[RFC PATCH]debugfs:Fix terminology inconsistency of dir name to mount debugfs filesystem.
GeunSik Lim
Hi all,
I want to hear your opinions about this proposal for consistency of
mount directory to mount debugfs filesystem that need by ftrace infrastructure.
Um... I appended "RFC" word in the subject because this mail is my proposal just.
commit 1766a83645706100b1829bb422f852ec757c6f4b
Author: GeunSik,Lim <lee...@gmail.com>
Date: Tue May 26 13:49:23 2009 +0900
Fix terminology inconsistency of dir name to mount debugfs filesystem.
Many developers use "/debug/" directory name to mount debugfs filesystem
for ftrace according to ./Documentation/tracers/ftrace.txt file.
But, two directory names(ex:/debug/, /debugfs/) is existed in kernel source
like ftrace, DRM, Wireless, Network[sky2]files to mount debugfs filesystem.
I think that we don't have to select either "/debug/" directory name or
"/debugfs/" directory name for terminology consistency.
debugfs means debug filesystem for debugging easy to use by greg kroah
hartman. "/debug/" name is suitable as directory name of debugfs for
tracing using ftrace like "/sys/" of sysfs(system filesystem).
-debugfs related reference: http://lwn.net/Articles/115405/
Fix inconsistency of directory name according to duplicated expression
to mount debugfs.
Signed-off-by: GeunSik Lim <geuns...@samsung.com>
---
Documentation/DocBook/debugobjects.tmpl | 2 +-
drivers/block/pktcdvd.c | 2 +-
drivers/gpu/drm/drm_debugfs.c | 12 ++++++------
drivers/gpu/drm/drm_drv.c | 2 +-
drivers/gpu/drm/drm_stub.c | 2 +-
drivers/net/Kconfig | 4 ++--
drivers/net/wimax/i2400m/i2400m.h | 2 +-
drivers/net/wireless/libertas/README | 12 ++++++------
include/linux/kernel.h | 2 +-
kernel/trace/Kconfig | 10 +++++-----
kernel/trace/trace.c | 2 +-
11 files changed, 26 insertions(+), 26 deletions(-)
diff --git a/Documentation/DocBook/debugobjects.tmpl b/Documentation/DocBook/debugobjects.tmpl
index 7f5f218..9beb77a 100644
--- a/Documentation/DocBook/debugobjects.tmpl
+++ b/Documentation/DocBook/debugobjects.tmpl
@@ -106,7 +106,7 @@
number of errors are printk'ed including a full stack trace.
</para>
<para>
- The statistics are available via debugfs/debug_objects/stats.
+ The statistics are available via /debug/debug_objects/stats.
They provide information about the number of warnings and the
number of successful fixups along with information about the
usage of the internal tracking objects and the state of the
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index dc7a8c3..36989b0 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -430,7 +430,7 @@ static void pkt_sysfs_cleanup(void)
/********************************************************************
entries in debugfs
- /debugfs/pktcdvd[0-7]/
+ /debug/pktcdvd[0-7]/
info
*******************************************************************/
diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
index c77c6c6..04a2ccf 100644
--- a/drivers/gpu/drm/drm_debugfs.c
+++ b/drivers/gpu/drm/drm_debugfs.c
@@ -105,7 +105,7 @@ int drm_debugfs_create_files(struct drm_info_list *files, int count,
ent = debugfs_create_file(files[i].name, S_IFREG | S_IRUGO,
root, tmp, &drm_debugfs_fops);
if (!ent) {
- DRM_ERROR("Cannot create /debugfs/dri/%s/%s\n",
+ DRM_ERROR("Cannot create /debug/dri/%s/%s\n",
name, files[i].name);
drm_free(tmp, sizeof(struct drm_info_node),
_DRM_DRIVER);
@@ -133,9 +133,9 @@ EXPORT_SYMBOL(drm_debugfs_create_files);
* \param minor device minor number
* \param root DRI debugfs dir entry.
*
- * Create the DRI debugfs root entry "/debugfs/dri", the device debugfs root entry
- * "/debugfs/dri/%minor%/", and each entry in debugfs_list as
- * "/debugfs/dri/%minor%/%name%".
+ * Create the DRI debugfs root entry "/debug/dri", the device debugfs root entry
+ * "/debug/dri/%minor%/", and each entry in debugfs_list as
+ * "/debug/dri/%minor%/%name%".
*/
int drm_debugfs_init(struct drm_minor *minor, int minor_id,
struct dentry *root)
@@ -148,7 +148,7 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
sprintf(name, "%d", minor_id);
minor->debugfs_root = debugfs_create_dir(name, root);
if (!minor->debugfs_root) {
- DRM_ERROR("Cannot create /debugfs/dri/%s\n", name);
+ DRM_ERROR("Cannot create /debug/dri/%s\n", name);
return -1;
}
@@ -165,7 +165,7 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
ret = dev->driver->debugfs_init(minor);
if (ret) {
DRM_ERROR("DRM: Driver failed to initialize "
- "/debugfs/dri.\n");
+ "/debug/dri.\n");
return ret;
}
}
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 019b7c5..5472e67 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -339,7 +339,7 @@ static int __init drm_core_init(void)
drm_debugfs_root = debugfs_create_dir("dri", NULL);
if (!drm_debugfs_root) {
- DRM_ERROR("Cannot create /debugfs/dri\n");
+ DRM_ERROR("Cannot create /debug/dri\n");
ret = -1;
goto err_p3;
}
diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index b9631e3..9488769 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -328,7 +328,7 @@ static int drm_get_minor(struct drm_device *dev, struct drm_minor **minor, int t
#if defined(CONFIG_DEBUG_FS)
ret = drm_debugfs_init(new_minor, minor_id, drm_debugfs_root);
if (ret) {
- DRM_ERROR("DRM: Failed to initialize /debugfs/dri.\n");
+ DRM_ERROR("DRM: Failed to initialize /debug/dri.\n");
goto err_g2;
}
#endif
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 214a92d..898c269 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -2200,7 +2200,7 @@ config SKGE_DEBUG
depends on SKGE && DEBUG_FS
help
This option adds the ability to dump driver state for debugging.
- The file debugfs/skge/ethX displays the state of the internal
+ The file /debug/skge/ethX displays the state of the internal
transmit and receive rings.
If unsure, say N.
@@ -2226,7 +2226,7 @@ config SKY2_DEBUG
depends on SKY2 && DEBUG_FS
help
This option adds the ability to dump driver state for debugging.
- The file debugfs/sky2/ethX displays the state of the internal
+ The file /debug/sky2/ethX displays the state of the internal
transmit and receive rings.
If unsure, say N.
diff --git a/drivers/net/wimax/i2400m/i2400m.h b/drivers/net/wimax/i2400m/i2400m.h
index 3ae2df3..2366696 100644
--- a/drivers/net/wimax/i2400m/i2400m.h
+++ b/drivers/net/wimax/i2400m/i2400m.h
@@ -389,7 +389,7 @@ struct i2400m {
unsigned ready:1; /* all probing steps done */
unsigned rx_reorder:1; /* RX reorder is enabled */
u8 trace_msg_from_user; /* echo rx msgs to 'trace' pipe */
- /* typed u8 so debugfs/u8 can tweak */
+ /* typed u8 so /debug/u8 can tweak */
enum i2400m_system_state state;
wait_queue_head_t state_wq; /* Woken up when on state updates */
diff --git a/drivers/net/wireless/libertas/README b/drivers/net/wireless/libertas/README
index d860fc3..11616ba 100644
--- a/drivers/net/wireless/libertas/README
+++ b/drivers/net/wireless/libertas/README
@@ -72,7 +72,7 @@ rdrf
location that is to be read. This parameter must be specified in
hexadecimal (its possible to preceed preceding the number with a "0x").
- Path: /debugfs/libertas_wireless/ethX/registers/
+ Path: /debug/libertas_wireless/ethX/registers/
Usage:
echo "0xa123" > rdmac ; cat rdmac
@@ -95,7 +95,7 @@ wrrf
sleepparams
This command is used to set the sleepclock configurations
- Path: /debugfs/libertas_wireless/ethX/
+ Path: /debug/libertas_wireless/ethX/
Usage:
cat sleepparams: reads the current sleepclock configuration
@@ -115,7 +115,7 @@ subscribed_events
The subscribed_events directory contains the interface for the
subscribed events API.
- Path: /debugfs/libertas_wireless/ethX/subscribed_events/
+ Path: /debug/libertas_wireless/ethX/subscribed_events/
Each event is represented by a filename. Each filename consists of the
following three fields:
@@ -165,7 +165,7 @@ subscribed_events
extscan
This command is used to do a specific scan.
- Path: /debugfs/libertas_wireless/ethX/
+ Path: /debug/libertas_wireless/ethX/
Usage: echo "SSID" > extscan
@@ -179,7 +179,7 @@ getscantable
Display the current contents of the driver scan table (ie. get the
scan results).
- Path: /debugfs/libertas_wireless/ethX/
+ Path: /debug/libertas_wireless/ethX/
Usage:
cat getscantable
@@ -188,7 +188,7 @@ setuserscan
Initiate a customized scan and retrieve the results
- Path: /debugfs/libertas_wireless/ethX/
+ Path: /debug/libertas_wireless/ethX/
Usage:
echo "[ARGS]" > setuserscan
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 883cd44..7ffa753 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -406,7 +406,7 @@ static inline char *pack_hex_byte(char *buf, u8 byte)
*
* Use tracing_on/tracing_off when you want to quickly turn on or off
* tracing. It simply enables or disables the recording of the trace events.
- * This also corresponds to the user space debugfs/tracing/tracing_on
+ * This also corresponds to the user space /debug/tracing/tracing_on
* file, which gives a means for the kernel and userspace to interact.
* Place a tracing_off() in the kernel where you want tracing to end.
* From user space, examine the trace, and then echo 1 > tracing_on
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 417d198..7fcc3d6 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -120,7 +120,7 @@ config IRQSOFF_TRACER
disabled by default and can be runtime (re-)started
via:
- echo 0 > /debugfs/tracing/tracing_max_latency
+ echo 0 > /debug/tracing/tracing_max_latency
(Note that kernel size and overhead increases with this option
enabled. This option and the preempt-off timing option can be
@@ -141,7 +141,7 @@ config PREEMPT_TRACER
disabled by default and can be runtime (re-)started
via:
- echo 0 > /debugfs/tracing/tracing_max_latency
+ echo 0 > /debug/tracing/tracing_max_latency
(Note that kernel size and overhead increases with this option
enabled. This option and the irqs-off timing option can be
@@ -213,7 +213,7 @@ config TRACE_BRANCH_PROFILING
This tracer profiles all the the likely and unlikely macros
in the kernel. It will display the results in:
- /debugfs/tracing/profile_annotated_branch
+ /debug/tracing/profile_annotated_branch
Note: this will add a significant overhead, only turn this
on if you need to profile the system's use of these macros.
@@ -228,7 +228,7 @@ config PROFILE_ALL_BRANCHES
taken in the kernel is recorded whether it hit or miss.
The results will be displayed in:
- /debugfs/tracing/profile_branch
+ /debug/tracing/profile_branch
This configuration, when enabled, will impose a great overhead
on the system. This should only be enabled when the system
@@ -276,7 +276,7 @@ config STACK_TRACER
select KALLSYMS
help
This special tracer records the maximum stack footprint of the
- kernel and displays it in debugfs/tracing/stack_trace.
+ kernel and displays it in /debug/tracing/stack_trace.
This tracer works by hooking into every function call that the
kernel executes, and keeping a maximum stack depth value and
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index cda81ec..b474e8c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -335,7 +335,7 @@ static raw_spinlock_t ftrace_max_lock =
/*
* Copy the new maximum trace into the separate maximum-trace
* structure. (this way the maximum trace is permanently saved,
- * for later retrieval via /debugfs/tracing/latency_trace)
+ * for later retrieval via /debug/tracing/latency_trace)
*/
static void
__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
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GeunSik Lim (ELS - OS Group - S/W Lab - SAIT - SAMSUNG)
e-Mail :1) geuns...@samsung.com
2) lee...@gmail.com , lee...@gmail.com
HomePage: http://intomail.dnip.net/invain/me/
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Iñaky Pérez-González
> Hi all,
>
> I want to hear your opinions about this proposal for consistency of
> mount directory to mount debugfs filesystem that need by ftrace
> infrastructure. Um... I appended "RFC" word in the subject because this
> mail is my proposal just.
>
>
> commit 1766a83645706100b1829bb422f852ec757c6f4b
> Author: GeunSik,Lim <lee...@gmail.com>
> Date: Tue May 26 13:49:23 2009 +0900
>
> Fix terminology inconsistency of dir name to mount debugfs filesystem.
>
> Many developers use "/debug/" directory name to mount debugfs
> filesystem for ftrace according to ./Documentation/tracers/ftrace.txt file.
>
> But, two directory names(ex:/debug/, /debugfs/) is existed in kernel
> source like ftrace, DRM, Wireless, Network[sky2]files to mount debugfs
> filesystem. I think that we don't have to select either "/debug/" directory
> name or "/debugfs/" directory name for terminology consistency.
>
> debugfs means debug filesystem for debugging easy to use by greg
> kroah hartman. "/debug/" name is suitable as directory name of debugfs for
> tracing using ftrace like "/sys/" of sysfs(system filesystem). -debugfs
> related reference: http://lwn.net/Articles/115405/
>
> Fix inconsistency of directory name according to duplicated
> expression to mount debugfs.
>
> Signed-off-by: GeunSik Lim <geuns...@samsung.com>
For the WiMAX part, not really an issue:
Acked-By: Inaky Perez-Gonzalez <in...@linux.intel.com>
Steven Rostedt
On Tue, 26 May 2009, GeunSik Lim wrote:
>
>
> Hi all,
>
> I want to hear your opinions about this proposal for consistency of
> mount directory to mount debugfs filesystem that need by ftrace infrastructure.
> Um... I appended "RFC" word in the subject because this mail is my proposal just.
>
>
> commit 1766a83645706100b1829bb422f852ec757c6f4b
> Author: GeunSik,Lim <lee...@gmail.com>
> Date: Tue May 26 13:49:23 2009 +0900
>
> Fix terminology inconsistency of dir name to mount debugfs filesystem.
>
> Many developers use "/debug/" directory name to mount debugfs filesystem
> for ftrace according to ./Documentation/tracers/ftrace.txt file.
>
> But, two directory names(ex:/debug/, /debugfs/) is existed in kernel source
> like ftrace, DRM, Wireless, Network[sky2]files to mount debugfs filesystem.
> I think that we don't have to select either "/debug/" directory name or
> "/debugfs/" directory name for terminology consistency.
>
> debugfs means debug filesystem for debugging easy to use by greg kroah
> hartman. "/debug/" name is suitable as directory name of debugfs for
> tracing using ftrace like "/sys/" of sysfs(system filesystem).
> -debugfs related reference: http://lwn.net/Articles/115405/
>
> Fix inconsistency of directory name according to duplicated expression
> to mount debugfs.
>
> Signed-off-by: GeunSik Lim <geuns...@samsung.com>
I'm guilty of using both /debug and /debugfs in comments. In practice, I
only use /debug.
But...
The filesystem Nazi's out there will argue that the proper place to mount
the debugfs filesystem is /sys/kernel/debug. I personally find that
location annoying.
-- Steve
Greg KH
Why?
When I created debugfs, I was told that I had to pick a place to mount
it so that everyone could write scripts that "knew" where it would be.
So we picked /sys/kernel/debug/ and the code creates the mount point to
put it there. Now distros actually mount debugfs at that location.
So, now you don't like this? After it's become a standard? Ick.
Becides, /debug/ is pretty presumptious, it's as if debugging the kernel
is a system-wide thing :)
So please, don't use /debug/ use the standard, defined, and ACTUALLY
USED BY DISTROS TODAY mount point of /sys/kernel/debug/
If you want to create your own symlink from /debug/ to that location to
make it easier to type, feel free, but do not hard code any scripts to
use that location, or they are going to break.
thanks,
greg k-h
Steven Rostedt
On Tue, 26 May 2009, Greg KH wrote:
> >
> > The filesystem Nazi's out there will argue that the proper place to mount
> > the debugfs filesystem is /sys/kernel/debug. I personally find that
> > location annoying.
>
> Why?
Because it is too much to type ;-)
>
> When I created debugfs, I was told that I had to pick a place to mount
> it so that everyone could write scripts that "knew" where it would be.
>
> So we picked /sys/kernel/debug/ and the code creates the mount point to
> put it there. Now distros actually mount debugfs at that location.
>
> So, now you don't like this? After it's become a standard? Ick.
>
> Becides, /debug/ is pretty presumptious, it's as if debugging the kernel
> is a system-wide thing :)
>
> So please, don't use /debug/ use the standard, defined, and ACTUALLY
> USED BY DISTROS TODAY mount point of /sys/kernel/debug/
>
> If you want to create your own symlink from /debug/ to that location to
> make it easier to type, feel free, but do not hard code any scripts to
> use that location, or they are going to break.
All my scripts search /proc/mounts to find where debugfs is mounted, then
it uses that.
Hmm, Not sure what packages in the distros use the default. I don't see
the debugfs in /etc/fstab in any of my machines.
-- Steve
Greg KH
> All my scripts search /proc/mounts to find where debugfs is mounted, then
> it uses that.
Good.
> Hmm, Not sure what packages in the distros use the default. I don't see
> the debugfs in /etc/fstab in any of my machines.
It's in mine, I don't know what packages use it at the moment.
thanks,
greg k-h
GeunSik Lim
>
> On Tue, 26 May 2009, Greg KH wrote:
>> >
>> > The filesystem Nazi's out there will argue that the proper place to mount
>> > the debugfs filesystem is /sys/kernel/debug. I personally find that
>> > location annoying.
>>
>> Why?
>
> Because it is too much to type ;-)
source all over the world, I think that a regular rules or consistency
is important
as greg k-h explained.
Recently, I read "ftrace-world.odp" presentation file of steven rostedt.
For example, about Mounting debugfs...
#> mount -t debugfs nodev /sys/kernel/debug
OR
#> mkdir /debug
#> mount -t debugfs nodev /debug
I want that we will reach a consensus about mount directory name of
debugfs filesystem to avoid confusing among the kernel developers.
/debug/ ?
or /sys/kernel/debug/?
.....
Frankly speaking, I like /sys/kernel/debug/ rule is better than /debug/ rule
for consistency.
>
>>
>> When I created debugfs, I was told that I had to pick a place to mount
>> it so that everyone could write scripts that "knew" where it would be.
>>
>> So we picked /sys/kernel/debug/ and the code creates the mount point to
>> put it there. Now distros actually mount debugfs at that location.
>>
>> So, now you don't like this? After it's become a standard? Ick.
>>
>> Becides, /debug/ is pretty presumptious, it's as if debugging the kernel
>> is a system-wide thing :)
>>
>> So please, don't use /debug/ use the standard, defined, and ACTUALLY
>> USED BY DISTROS TODAY mount point of /sys/kernel/debug/
>>
>> If you want to create your own symlink from /debug/ to that location to
>> make it easier to type, feel free, but do not hard code any scripts to
>> use that location, or they are going to break.
>
> All my scripts search /proc/mounts to find where debugfs is mounted, then
> it uses that.
>
> Hmm, Not sure what packages in the distros use the default. I don't see
> the debugfs in /etc/fstab in any of my machines.
>
Yes.. In my case, I use linux distributions like Ubuntu 8.10, Fedora
9/10, CENTOS 5.3 currently. This distributions use proc , tmpfs,
devpts, sysfs for official release
by default.
> -- Steve
>
>
--
Regards,
GeunSik Lim
Steven Rostedt
And this is why I always mention that directory.
>
> >
> >>
> >> When I created debugfs, I was told that I had to pick a place to mount
> >> it so that everyone could write scripts that "knew" where it would be.
> >>
> >> So we picked /sys/kernel/debug/ and the code creates the mount point to
> >> put it there. Now distros actually mount debugfs at that location.
> >>
> >> So, now you don't like this? After it's become a standard? Ick.
> >>
> >> Becides, /debug/ is pretty presumptious, it's as if debugging the kernel
> >> is a system-wide thing :)
> >>
> >> So please, don't use /debug/ use the standard, defined, and ACTUALLY
> >> USED BY DISTROS TODAY mount point of /sys/kernel/debug/
> >>
> >> If you want to create your own symlink from /debug/ to that location to
> >> make it easier to type, feel free, but do not hard code any scripts to
> >> use that location, or they are going to break.
> >
> > All my scripts search /proc/mounts to find where debugfs is mounted, then
> > it uses that.
> >
> > Hmm, Not sure what packages in the distros use the default. I don't see
> > the debugfs in /etc/fstab in any of my machines.
> >
> Yes.. In my case, I use linux distributions like Ubuntu 8.10, Fedora
> 9/10, CENTOS 5.3 currently. This distributions use proc , tmpfs,
> devpts, sysfs for official release
> by default.
>
The key thing is not to have scripts depend on a path. When debugfs is
enabled in a kernel, you automatically get /sys/kernel/debug, so that is a
natural place to mount it.
I have also suggested to people (as Greg suggested earlier to me) that you
can mount it there and then make a soft link to it. Which also works.
I personally just mount it at /debug.
To handle the scripts problem, all my scripts start with:
# grep debugfs /proc/mounts | cut -d ' ' -f 2
I also have a C function to do a search for debugfs in /proc/mounts.
If you look in Documentation/trace/ftrace.txt I have:
===
To mount the debugfs system:
# mkdir /debug
# mount -t debugfs nodev /debug
( Note: it is more common to mount at /sys/kernel/debug, but for
simplicity this document will use /debug)
===
Thus it is a personal preference of mine to put it at /debug. But I do not
hide the fact that it is recommended to be in /sys/kernel/debug. Heck, I'm
the one that brought to light that path in this thread. I just curse it
everytime I have to say it ;-)
-- Steve
GeunSik Lim
Thank you for explanation about history of "/debug/" and "/sys/kernel/debug/"
in the ./Documentations/trace/ftrace.txt file.
Do I have to change contents of patch file from "/debug/***" to "debug/***"
to consider both "/debug/"directory and
"/sys/kernel/debug/ (initial directory by debugfs)" directory in the
my patch file?
Or,
Do I have to keep "/" character of "/debug" in my patch file that I proposed
because many contributors already use "/debugfs/" or "/debug/"
in their patch files?
Steven, Can you advise me?
>
> -- Steve
>
--
Regards,
GeunSik Lim ( SAMSUNG ELECTRONICS)
Blog : http://blog.naver.com/invain/
e-Mail: geuns...@samsung.com
lee...@gmail.com , lee...@gmail.com
Jaswinder Singh Rajput
On Tue, 2009-05-26 at 22:38 -0400, Steven Rostedt wrote:
> If you look in Documentation/trace/ftrace.txt I have:
>
> ===
> To mount the debugfs system:
>
> # mkdir /debug
> # mount -t debugfs nodev /debug
>
> ( Note: it is more common to mount at /sys/kernel/debug, but for
> simplicity this document will use /debug)
> ===
>
Please standardize Documentation/trace/ftrace.txt and avoid confusion to
users:
===
To mount the debugfs system:
# mount -t debugfs nodev /sys/kernel/debug
===
Thanks,
--
JSR
Steven Rostedt
On Wed, 27 May 2009, Jaswinder Singh Rajput wrote:
> Hello Steve,
>
> On Tue, 2009-05-26 at 22:38 -0400, Steven Rostedt wrote:
>
> > If you look in Documentation/trace/ftrace.txt I have:
> >
> > ===
> > To mount the debugfs system:
> >
> > # mkdir /debug
> > # mount -t debugfs nodev /debug
> >
> > ( Note: it is more common to mount at /sys/kernel/debug, but for
> > simplicity this document will use /debug)
> > ===
> >
>
> Please standardize Documentation/trace/ftrace.txt and avoid confusion to
> users:
>
> ===
> To mount the debugfs system:
>
> # mount -t debugfs nodev /sys/kernel/debug
> ===
I really don't want to do that. Then I would need to show
# echo function_graph > /sys/kernel/debug/current_trace
Which I really do not like. I state that the common place to mount it is
in /sys/kernel/debug, But my examples are much easier to understand if
I just do: # echo function_graph > /debug/current_trace
-- Steve
Greg KH
>
> On Wed, 27 May 2009, Jaswinder Singh Rajput wrote:
>
> > Hello Steve,
> >
> > On Tue, 2009-05-26 at 22:38 -0400, Steven Rostedt wrote:
> >
> > > If you look in Documentation/trace/ftrace.txt I have:
> > >
> > > ===
> > > To mount the debugfs system:
> > >
> > > # mkdir /debug
> > > # mount -t debugfs nodev /debug
> > >
> > > ( Note: it is more common to mount at /sys/kernel/debug, but for
> > > simplicity this document will use /debug)
> > > ===
> > >
> >
> > Please standardize Documentation/trace/ftrace.txt and avoid confusion to
> > users:
> >
> > ===
> > To mount the debugfs system:
> >
> > # mount -t debugfs nodev /sys/kernel/debug
> > ===
>
> I really don't want to do that. Then I would need to show
>
> # echo function_graph > /sys/kernel/debug/current_trace
>
> Which I really do not like. I state that the common place to mount it is
> in /sys/kernel/debug, But my examples are much easier to understand if
> I just do: # echo function_graph > /debug/current_trace
It's not just the "common" place, it is the DOCUMENTED PLACE.
I'm sorry you have to type a long path, perhaps you wish to invest in a
tab key for auto-completion :)
Again, distros already mount debugfs at this location, please don't
confuse people just because you are annoyed at the length of the path.
thanks,
greg k-h
Steven Rostedt
On Wed, 27 May 2009, Greg KH wrote:
> > > >
> > > > ( Note: it is more common to mount at /sys/kernel/debug, but for
> > > > simplicity this document will use /debug)
> > > > ===
> >
> > I really don't want to do that. Then I would need to show
> >
> > # echo function_graph > /sys/kernel/debug/current_trace
> >
> > Which I really do not like. I state that the common place to mount it is
> > in /sys/kernel/debug, But my examples are much easier to understand if
> > I just do: # echo function_graph > /debug/current_trace
>
> It's not just the "common" place, it is the DOCUMENTED PLACE.
I can change the wording to be "documented" or "distro mounted".
>
> I'm sorry you have to type a long path, perhaps you wish to invest in a
> tab key for auto-completion :)
>
> Again, distros already mount debugfs at this location, please don't
> confuse people just because you are annoyed at the length of the path.
Have you found which packages do that?
The point is that the document is more interested in showing the files
that are being used, and if I add /sys/kernel/debug/ in front of every
file, that just distracts from the eye. As stated:
"but for simplicity this document will use /debug"
I'll update ftrace.txt to explain it better.
Something like:
=====
Debugfs is mounted by some packages at /sys/kernel/debugfs. If it is not
you can mount it by adding
debugfs /sys/kernel/debug debugfs defaults 0 0
to your /etc/fstab, or by manually mounting it:
# mount -t debugfs nodev /sys/kernel/debugfs
For simplicity, this document will assume that you also added the
following symbolic link:
# ln -s /sys/kernel/debugfs /debug
=====
Then I can keep the document simplistic and still have the "DOCUMENTED"
locating specified.
-- Steve
Greg KH
> > I'm sorry you have to type a long path, perhaps you wish to invest in a
> > tab key for auto-completion :)
> >
> > Again, distros already mount debugfs at this location, please don't
> > confuse people just because you are annoyed at the length of the path.
>
> Have you found which packages do that?
The base system packages on all openSUSE and SLE11 releases. Possibly
SLE10 also does it, but I don't have a running instance of that at the
moment.
> The point is that the document is more interested in showing the files
> that are being used, and if I add /sys/kernel/debug/ in front of every
> file, that just distracts from the eye. As stated:
>
> "but for simplicity this document will use /debug"
Sorry for the "distraction", but that goes against documentation on your
machine:
$ man mount | grep -A 3 "Mount options for debugfs"
Mount options for debugfs
The debugfs file system is a pseudo file system, traditionally mounted
on /sys/kernel/debug. There are no mount options.
It's not only a documented standard, it's a "tradition" :)
Please fix your documentation.
thanks,
greg k-h
GeunSik Lim
>
> On Wed, 27 May 2009, Greg KH wrote:
>> > > >
>> > > > ( Note: it is more common to mount at /sys/kernel/debug, but for
>> > > > simplicity this document will use /debug)
>> > > > ===
>
>> >
>> > I really don't want to do that. Then I would need to show
>> >
>> > # echo function_graph > /sys/kernel/debug/current_trace
>> >
>> > Which I really do not like. I state that the common place to mount it is
>> > in /sys/kernel/debug, But my examples are much easier to understand if
>> > I just do: # echo function_graph > /debug/current_trace
>>
>> It's not just the "common" place, it is the DOCUMENTED PLACE.
>
> I can change the wording to be "documented" or "distro mounted".
>
>>
>> I'm sorry you have to type a long path, perhaps you wish to invest in a
>> tab key for auto-completion :)
>>
>> Again, distros already mount debugfs at this location, please don't
>> confuse people just because you are annoyed at the length of the path.
>
> Have you found which packages do that?
>
> The point is that the document is more interested in showing the files
> that are being used, and if I add /sys/kernel/debug/ in front of every
> file, that just distracts from the eye. As stated:
>
> "but for simplicity this document will use /debug"
>
> I'll update ftrace.txt to explain it better.
>
> Something like:
>
> =====
> Debugfs is mounted by some packages at /sys/kernel/debugfs. If it is not
> you can mount it by adding
>
> debugfs /sys/kernel/debug debugfs defaults 0 0
>
> to your /etc/fstab, or by manually mounting it:
>
> # mount -t debugfs nodev /sys/kernel/debugfs
>
> For simplicity, this document will assume that you also added the
> following symbolic link:
>
> # ln -s /sys/kernel/debugfs /debug
> =====
/sys/kernel/debugfs --> /sys/kenrel/debug
Default directory of debugfs filesystem is /sys/kernel/debug/ as you know.
>
> Then I can keep the document simplistic and still have the "DOCUMENTED"
> locating specified.
>
> -- Steve
>
>
--
Regards,
GeunSik Lim ( SAMSUNG ELECTRONICS)
Blog : http://blog.naver.com/invain/
e-Mail: geuns...@samsung.com
lee...@gmail.com , lee...@gmail.com
GeunSik Lim
Dear Greg and Steen,
Thanks your advices and opinions about a confusion according to
too many mount directory names for debugfs. I made rfc v2 patch file again like belows.
Can I hear your advices about below patch contents?.
Regards,
GeunSik Lim.
Subject: [PATCH] Fix terminology inconsistency of dir name to mount debugfs filesystem.
Many developers use "/debug/" or "/debugfs/ directory name to mount
debugfs filesystem for ftrace according to
./Documentation/tracers/ftrace.txt file.
And, three directory names(ex:/debug/, /debugfs/, /sys/kernel/debug/) is
existed in kernel source like ftrace, DRM, Wireless, Network[sky2]files
to mount debugfs filesystem.
debugfs means debug filesystem for debugging easy to use by greg kroah
hartman. "/sys/kernel/debug/" name is suitable as directory name
of debugfs filesystem.
-debugfs related reference: http://lwn.net/Articles/115405/
Fix inconsistency of directory name to mount debugfs filesystem.
Signed-off-by: GeunSik Lim <geuns...@samsung.com>
Acked-By: Inaky Perez-Gonzalez <in...@linux.intel.com>
CC: Greg KH <gr...@kroah.com>
CC: Steven Rostedt <ros...@goodmis.org>
CC: linux-kernel <linux-...@vger.kernel.org>
---
Documentation/DocBook/debugobjects.tmpl | 2 +-
Documentation/cdrom/packet-writing.txt | 2 +-
Documentation/fault-injection/fault-injection.txt | 70 +++++-----
Documentation/kprobes.txt | 6 +-
Documentation/trace/ftrace.txt | 166 ++++++++++----------
Documentation/trace/mmiotrace.txt | 26 ++--
drivers/block/pktcdvd.c | 2 +-
drivers/gpu/drm/drm_debugfs.c | 12 +-
drivers/gpu/drm/drm_drv.c | 2 +-
drivers/gpu/drm/drm_stub.c | 2 +-
drivers/net/Kconfig | 4 +-
drivers/net/wimax/i2400m/i2400m.h | 2 +-
drivers/net/wireless/ath5k/Kconfig | 6 +-
drivers/net/wireless/libertas/README | 12 +-
drivers/scsi/lpfc/lpfc_debugfs.c | 4 +-
include/linux/kernel.h | 2 +-
include/linux/tracepoint.h | 4 +-
kernel/trace/Kconfig | 10 +-
kernel/trace/trace.c | 24 ++--
scripts/tracing/draw_functrace.py | 8 +-
20 files changed, 183 insertions(+), 183 deletions(-)
diff --git a/Documentation/DocBook/debugobjects.tmpl b/Documentation/DocBook/debugobjects.tmpl
index 7f5f218..08ff908 100644
--- a/Documentation/DocBook/debugobjects.tmpl
+++ b/Documentation/DocBook/debugobjects.tmpl
@@ -106,7 +106,7 @@
number of errors are printk'ed including a full stack trace.
</para>
<para>
- The statistics are available via debugfs/debug_objects/stats.
+ The statistics are available via /sys/kernel/debug/debug_objects/stats.
They provide information about the number of warnings and the
number of successful fixups along with information about the
usage of the internal tracking objects and the state of the
diff --git a/Documentation/cdrom/packet-writing.txt b/Documentation/cdrom/packet-writing.txt
index cf1f812..1c40777 100644
--- a/Documentation/cdrom/packet-writing.txt
+++ b/Documentation/cdrom/packet-writing.txt
@@ -117,7 +117,7 @@ Using the pktcdvd debugfs interface
To read pktcdvd device infos in human readable form, do:
- # cat /debug/pktcdvd/pktcdvd[0-7]/info
+ # cat /sys/kernel/debug/pktcdvd/pktcdvd[0-7]/info
For a description of the debugfs interface look into the file:
diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt
index 4bc374a..0793056 100644
--- a/Documentation/fault-injection/fault-injection.txt
+++ b/Documentation/fault-injection/fault-injection.txt
@@ -29,16 +29,16 @@ o debugfs entries
fault-inject-debugfs kernel module provides some debugfs entries for runtime
configuration of fault-injection capabilities.
-- /debug/fail*/probability:
+- /sys/kernel/debug/fail*/probability:
likelihood of failure injection, in percent.
Format: <percent>
Note that one-failure-per-hundred is a very high error rate
for some testcases. Consider setting probability=100 and configure
- /debug/fail*/interval for such testcases.
+ /sys/kernel/debug/fail*/interval for such testcases.
-- /debug/fail*/interval:
+- /sys/kernel/debug/fail*/interval:
specifies the interval between failures, for calls to
should_fail() that pass all the other tests.
@@ -46,18 +46,18 @@ configuration of fault-injection capabilities.
Note that if you enable this, by setting interval>1, you will
probably want to set probability=100.
-- /debug/fail*/times:
+- /sys/kernel/debug/fail*/times:
specifies how many times failures may happen at most.
A value of -1 means "no limit".
-- /debug/fail*/space:
+- /sys/kernel/debug/fail*/space:
specifies an initial resource "budget", decremented by "size"
on each call to should_fail(,size). Failure injection is
suppressed until "space" reaches zero.
-- /debug/fail*/verbose
+- /sys/kernel/debug/fail*/verbose
Format: { 0 | 1 | 2 }
specifies the verbosity of the messages when failure is
@@ -65,17 +65,17 @@ configuration of fault-injection capabilities.
log line per failure; '2' will print a call trace too -- useful
to debug the problems revealed by fault injection.
-- /debug/fail*/task-filter:
+- /sys/kernel/debug/fail*/task-filter:
Format: { 'Y' | 'N' }
A value of 'N' disables filtering by process (default).
Any positive value limits failures to only processes indicated by
/proc/<pid>/make-it-fail==1.
-- /debug/fail*/require-start:
-- /debug/fail*/require-end:
-- /debug/fail*/reject-start:
-- /debug/fail*/reject-end:
+- /sys/kernel/debug/fail*/require-start:
+- /sys/kernel/debug/fail*/require-end:
+- /sys/kernel/debug/fail*/reject-start:
+- /sys/kernel/debug/fail*/reject-end:
specifies the range of virtual addresses tested during
stacktrace walking. Failure is injected only if some caller
@@ -84,26 +84,26 @@ configuration of fault-injection capabilities.
Default required range is [0,ULONG_MAX) (whole of virtual address space).
Default rejected range is [0,0).
-- /debug/fail*/stacktrace-depth:
+- /sys/kernel/debug/fail*/stacktrace-depth:
specifies the maximum stacktrace depth walked during search
for a caller within [require-start,require-end) OR
[reject-start,reject-end).
-- /debug/fail_page_alloc/ignore-gfp-highmem:
+- /sys/kernel/debug/fail_page_alloc/ignore-gfp-highmem:
Format: { 'Y' | 'N' }
default is 'N', setting it to 'Y' won't inject failures into
highmem/user allocations.
-- /debug/failslab/ignore-gfp-wait:
-- /debug/fail_page_alloc/ignore-gfp-wait:
+- /sys/kernel/debug/failslab/ignore-gfp-wait:
+- /sys/kernel/debug/fail_page_alloc/ignore-gfp-wait:
Format: { 'Y' | 'N' }
default is 'N', setting it to 'Y' will inject failures
only into non-sleep allocations (GFP_ATOMIC allocations).
-- /debug/fail_page_alloc/min-order:
+- /sys/kernel/debug/fail_page_alloc/min-order:
specifies the minimum page allocation order to be injected
failures.
@@ -166,13 +166,13 @@ o Inject slab allocation failures into module init/exit code
#!/bin/bash
FAILTYPE=failslab
-echo Y > /debug/$FAILTYPE/task-filter
-echo 10 > /debug/$FAILTYPE/probability
-echo 100 > /debug/$FAILTYPE/interval
-echo -1 > /debug/$FAILTYPE/times
-echo 0 > /debug/$FAILTYPE/space
-echo 2 > /debug/$FAILTYPE/verbose
-echo 1 > /debug/$FAILTYPE/ignore-gfp-wait
+echo Y > /sys/kernel/debug/$FAILTYPE/task-filter
+echo 10 > /sys/kernel/debug/$FAILTYPE/probability
+echo 100 > /sys/kernel/debug/$FAILTYPE/interval
+echo -1 > /sys/kernel/debug/$FAILTYPE/times
+echo 0 > /sys/kernel/debug/$FAILTYPE/space
+echo 2 > /sys/kernel/debug/$FAILTYPE/verbose
+echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-wait
faulty_system()
{
@@ -217,20 +217,20 @@ then
exit 1
fi
-cat /sys/module/$module/sections/.text > /debug/$FAILTYPE/require-start
-cat /sys/module/$module/sections/.data > /debug/$FAILTYPE/require-end
+cat /sys/module/$module/sections/.text > /sys/kernel/debug/$FAILTYPE/require-start
+cat /sys/module/$module/sections/.data > /sys/kernel/debug/$FAILTYPE/require-end
-echo N > /debug/$FAILTYPE/task-filter
-echo 10 > /debug/$FAILTYPE/probability
-echo 100 > /debug/$FAILTYPE/interval
-echo -1 > /debug/$FAILTYPE/times
-echo 0 > /debug/$FAILTYPE/space
-echo 2 > /debug/$FAILTYPE/verbose
-echo 1 > /debug/$FAILTYPE/ignore-gfp-wait
-echo 1 > /debug/$FAILTYPE/ignore-gfp-highmem
-echo 10 > /debug/$FAILTYPE/stacktrace-depth
+echo N > /sys/kernel/debug/$FAILTYPE/task-filter
+echo 10 > /sys/kernel/debug/$FAILTYPE/probability
+echo 100 > /sys/kernel/debug/$FAILTYPE/interval
+echo -1 > /sys/kernel/debug/$FAILTYPE/times
+echo 0 > /sys/kernel/debug/$FAILTYPE/space
+echo 2 > /sys/kernel/debug/$FAILTYPE/verbose
+echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-wait
+echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-highmem
+echo 10 > /sys/kernel/debug/$FAILTYPE/stacktrace-depth
-trap "echo 0 > /debug/$FAILTYPE/probability" SIGINT SIGTERM EXIT
+trap "echo 0 > /sys/kernel/debug/$FAILTYPE/probability" SIGINT SIGTERM EXIT
echo "Injecting errors into the module $module... (interrupt to stop)"
sleep 1000000
diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt
index 1e7a769..053037a 100644
--- a/Documentation/kprobes.txt
+++ b/Documentation/kprobes.txt
@@ -507,9 +507,9 @@ http://www.linuxsymposium.org/2006/linuxsymposium_procv2.pdf (pages 101-115)
Appendix A: The kprobes debugfs interface
With recent kernels (> 2.6.20) the list of registered kprobes is visible
-under the /debug/kprobes/ directory (assuming debugfs is mounted at /debug).
+under the /sys/kernel/debug/kprobes/ directory (assuming debugfs is mounted at //sys/kernel/debug).
-/debug/kprobes/list: Lists all registered probes on the system
+/sys/kernel/debug/kprobes/list: Lists all registered probes on the system
c015d71a k vfs_read+0x0
c011a316 j do_fork+0x0
@@ -525,7 +525,7 @@ virtual addresses that correspond to modules that've been unloaded),
such probes are marked with [GONE]. If the probe is temporarily disabled,
such probes are marked with [DISABLED].
-/debug/kprobes/enabled: Turn kprobes ON/OFF forcibly.
+/sys/kernel/debug/kprobes/enabled: Turn kprobes ON/OFF forcibly.
Provides a knob to globally and forcibly turn registered kprobes ON or OFF.
By default, all kprobes are enabled. By echoing "0" to this file, all
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index fd9a3e6..cbc6cca 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -35,11 +35,11 @@ well as the files to display output.
To mount the debugfs system:
- # mkdir /debug
- # mount -t debugfs nodev /debug
+ # mkdir /sys/kernel/debug
+ # mount -t debugfs nodev /sys/kernel/debug
( Note: it is more common to mount at /sys/kernel/debug, but for
- simplicity this document will use /debug)
+ simplicity this document will use /sys/kernel/debug)
That's it! (assuming that you have ftrace configured into your kernel)
@@ -389,18 +389,18 @@ trace_options
The trace_options file is used to control what gets printed in
the trace output. To see what is available, simply cat the file:
- cat /debug/tracing/trace_options
+ cat /sys/kernel/debug/tracing/trace_options
print-parent nosym-offset nosym-addr noverbose noraw nohex nobin \
noblock nostacktrace nosched-tree nouserstacktrace nosym-userobj
To disable one of the options, echo in the option prepended with
"no".
- echo noprint-parent > /debug/tracing/trace_options
+ echo noprint-parent > /sys/kernel/debug/tracing/trace_options
To enable an option, leave off the "no".
- echo sym-offset > /debug/tracing/trace_options
+ echo sym-offset > /sys/kernel/debug/tracing/trace_options
Here are the available options:
@@ -476,11 +476,11 @@ sched_switch
This tracer simply records schedule switches. Here is an example
of how to use it.
- # echo sched_switch > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo sched_switch > /sys/kernel/debug/tracing/current_tracer
+ # echo 1 > /sys/kernel/debug/tracing/tracing_enabled
# sleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > /sys/kernel/debug/tracing/tracing_enabled
+ # cat /sys/kernel/debug/tracing/trace
# tracer: sched_switch
#
@@ -574,13 +574,13 @@ new trace is saved.
To reset the maximum, echo 0 into tracing_max_latency. Here is
an example:
- # echo irqsoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo irqsoff > /sys/kernel/debug/tracing/current_tracer
+ # echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
+ # echo 1 > /sys/kernel/debug/tracing/tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > /sys/kernel/debug/tracing/tracing_enabled
+ # cat /sys/kernel/debug/tracing/latency_trace
# tracer: irqsoff
#
irqsoff latency trace v1.1.5 on 2.6.26
@@ -681,13 +681,13 @@ Like the irqsoff tracer, it records the maximum latency for
which preemption was disabled. The control of preemptoff tracer
is much like the irqsoff tracer.
- # echo preemptoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo preemptoff > /sys/kernel/debug/tracing/current_tracer
+ # echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
+ # echo 1 > /sys/kernel/debug/tracing/tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > /sys/kernel/debug/tracing/tracing_enabled
+ # cat /sys/kernel/debug/tracing/latency_trace
# tracer: preemptoff
#
preemptoff latency trace v1.1.5 on 2.6.26-rc8
@@ -828,13 +828,13 @@ tracer.
Again, using this trace is much like the irqsoff and preemptoff
tracers.
- # echo preemptirqsoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo preemptirqsoff > /sys/kernel/debug/tracing/current_tracer
+ # echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
+ # echo 1 > /sys/kernel/debug/tracing/tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > /sys/kernel/debug/tracing/tracing_enabled
+ # cat /sys/kernel/debug/tracing/latency_trace
# tracer: preemptirqsoff
#
preemptirqsoff latency trace v1.1.5 on 2.6.26-rc8
@@ -990,12 +990,12 @@ slightly differently than we did with the previous tracers.
Instead of performing an 'ls', we will run 'sleep 1' under
'chrt' which changes the priority of the task.
- # echo wakeup > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo wakeup > /sys/kernel/debug/tracing/current_tracer
+ # echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
+ # echo 1 > /sys/kernel/debug/tracing/tracing_enabled
# chrt -f 5 sleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > /sys/kernel/debug/tracing/tracing_enabled
+ # cat /sys/kernel/debug/tracing/latency_trace
# tracer: wakeup
#
wakeup latency trace v1.1.5 on 2.6.26-rc8
@@ -1105,11 +1105,11 @@ can be done from the debug file system. Make sure the
ftrace_enabled is set; otherwise this tracer is a nop.
# sysctl kernel.ftrace_enabled=1
- # echo function > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo function > /sys/kernel/debug/tracing/current_tracer
+ # echo 1 > /sys/kernel/debug/tracing/tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > /sys/kernel/debug/tracing/tracing_enabled
+ # cat /sys/kernel/debug/tracing/trace
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1146,7 +1146,7 @@ int trace_fd;
[...]
int main(int argc, char *argv[]) {
[...]
- trace_fd = open("/debug/tracing/tracing_enabled", O_WRONLY);
+ trace_fd = open("/sys/kernel/debug/tracing/tracing_enabled", O_WRONLY);
[...]
if (condition_hit()) {
write(trace_fd, "0", 1);
@@ -1155,7 +1155,7 @@ int main(int argc, char *argv[]) {
}
Note: Here we hard coded the path name. The debugfs mount is not
-guaranteed to be at /debug (and is more commonly at
+guaranteed to be at /sys/kernel/debug (and is more commonly at
/sys/kernel/debug). For simple one time traces, the above is
sufficent. For anything else, a search through /proc/mounts may
be needed to find where the debugfs file-system is mounted.
@@ -1164,16 +1164,16 @@ be needed to find where the debugfs file-system is mounted.
Single thread tracing
---------------------
-By writing into /debug/tracing/set_ftrace_pid you can trace a
+By writing into /sys/kernel/debug/tracing/set_ftrace_pid you can trace a
single thread. For example:
-# cat /debug/tracing/set_ftrace_pid
+# cat /sys/kernel/debug/tracing/set_ftrace_pid
no pid
-# echo 3111 > /debug/tracing/set_ftrace_pid
-# cat /debug/tracing/set_ftrace_pid
+# echo 3111 > /sys/kernel/debug/tracing/set_ftrace_pid
+# cat /sys/kernel/debug/tracing/set_ftrace_pid
3111
-# echo function > /debug/tracing/current_tracer
-# cat /debug/tracing/trace | head
+# echo function > /sys/kernel/debug/tracing/current_tracer
+# cat /sys/kernel/debug/tracing/trace | head
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1184,8 +1184,8 @@ no pid
yum-updatesd-3111 [003] 1637.254683: lock_hrtimer_base <-hrtimer_try_to_cancel
yum-updatesd-3111 [003] 1637.254685: fget_light <-do_sys_poll
yum-updatesd-3111 [003] 1637.254686: pipe_poll <-do_sys_poll
-# echo -1 > /debug/tracing/set_ftrace_pid
-# cat /debug/tracing/trace |head
+# echo -1 > /sys/kernel/debug/tracing/set_ftrace_pid
+# cat /sys/kernel/debug/tracing/trace |head
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1217,12 +1217,12 @@ int main (int argc, char **argv)
char line[64];
int s;
- ffd = open("/debug/tracing/current_tracer", O_WRONLY);
+ ffd = open("/sys/kernel/debug/tracing/current_tracer", O_WRONLY);
if (ffd < 0)
exit(-1);
write(ffd, "nop", 3);
- fd = open("/debug/tracing/set_ftrace_pid", O_WRONLY);
+ fd = open("/sys/kernel/debug/tracing/set_ftrace_pid", O_WRONLY);
s = sprintf(line, "%d\n", getpid());
write(fd, line, s);
@@ -1374,22 +1374,22 @@ want, depending on your needs.
tracing_cpu_mask file) or you might sometimes see unordered
function calls while cpu tracing switch.
- hide: echo nofuncgraph-cpu > /debug/tracing/trace_options
- show: echo funcgraph-cpu > /debug/tracing/trace_options
+ hide: echo nofuncgraph-cpu > /sys/kernel/debug/tracing/trace_options
+ show: echo funcgraph-cpu > /sys/kernel/debug/tracing/trace_options
- The duration (function's time of execution) is displayed on
the closing bracket line of a function or on the same line
than the current function in case of a leaf one. It is default
enabled.
- hide: echo nofuncgraph-duration > /debug/tracing/trace_options
- show: echo funcgraph-duration > /debug/tracing/trace_options
+ hide: echo nofuncgraph-duration > /sys/kernel/debug/tracing/trace_options
+ show: echo funcgraph-duration > /sys/kernel/debug/tracing/trace_options
- The overhead field precedes the duration field in case of
reached duration thresholds.
- hide: echo nofuncgraph-overhead > /debug/tracing/trace_options
- show: echo funcgraph-overhead > /debug/tracing/trace_options
+ hide: echo nofuncgraph-overhead > /sys/kernel/debug/tracing/trace_options
+ show: echo funcgraph-overhead > /sys/kernel/debug/tracing/trace_options
depends on: funcgraph-duration
ie:
@@ -1418,8 +1418,8 @@ want, depending on your needs.
- The task/pid field displays the thread cmdline and pid which
executed the function. It is default disabled.
- hide: echo nofuncgraph-proc > /debug/tracing/trace_options
- show: echo funcgraph-proc > /debug/tracing/trace_options
+ hide: echo nofuncgraph-proc > /sys/kernel/debug/tracing/trace_options
+ show: echo funcgraph-proc > /sys/kernel/debug/tracing/trace_options
ie:
@@ -1442,8 +1442,8 @@ want, depending on your needs.
system clock since it started. A snapshot of this time is
given on each entry/exit of functions
- hide: echo nofuncgraph-abstime > /debug/tracing/trace_options
- show: echo funcgraph-abstime > /debug/tracing/trace_options
+ hide: echo nofuncgraph-abstime > /sys/kernel/debug/tracing/trace_options
+ show: echo funcgraph-abstime > /sys/kernel/debug/tracing/trace_options
ie:
@@ -1540,7 +1540,7 @@ listed in:
available_filter_functions
- # cat /debug/tracing/available_filter_functions
+ # cat /sys/kernel/debug/tracing/available_filter_functions
put_prev_task_idle
kmem_cache_create
pick_next_task_rt
@@ -1552,12 +1552,12 @@ mutex_lock
If I am only interested in sys_nanosleep and hrtimer_interrupt:
# echo sys_nanosleep hrtimer_interrupt \
- > /debug/tracing/set_ftrace_filter
- # echo ftrace > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ > /sys/kernel/debug/tracing/set_ftrace_filter
+ # echo ftrace > /sys/kernel/debug/tracing/current_tracer
+ # echo 1 > /sys/kernel/debug/tracing/tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > /sys/kernel/debug/tracing/tracing_enabled
+ # cat /sys/kernel/debug/tracing/trace
# tracer: ftrace
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1568,7 +1568,7 @@ If I am only interested in sys_nanosleep and hrtimer_interrupt:
To see which functions are being traced, you can cat the file:
- # cat /debug/tracing/set_ftrace_filter
+ # cat /sys/kernel/debug/tracing/set_ftrace_filter
hrtimer_interrupt
sys_nanosleep
@@ -1588,7 +1588,7 @@ Note: It is better to use quotes to enclose the wild cards,
otherwise the shell may expand the parameters into names
of files in the local directory.
- # echo 'hrtimer_*' > /debug/tracing/set_ftrace_filter
+ # echo 'hrtimer_*' > /sys/kernel/debug/tracing/set_ftrace_filter
Produces:
@@ -1609,7 +1609,7 @@ Produces:
Notice that we lost the sys_nanosleep.
- # cat /debug/tracing/set_ftrace_filter
+ # cat /sys/kernel/debug/tracing/set_ftrace_filter
hrtimer_run_queues
hrtimer_run_pending
hrtimer_init
@@ -1635,17 +1635,17 @@ To append to the filters, use '>>'
To clear out a filter so that all functions will be recorded
again:
- # echo > /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo > /sys/kernel/debug/tracing/set_ftrace_filter
+ # cat /sys/kernel/debug/tracing/set_ftrace_filter
#
Again, now we want to append.
- # echo sys_nanosleep > /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo sys_nanosleep > /sys/kernel/debug/tracing/set_ftrace_filter
+ # cat /sys/kernel/debug/tracing/set_ftrace_filter
sys_nanosleep
- # echo 'hrtimer_*' >> /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo 'hrtimer_*' >> /sys/kernel/debug/tracing/set_ftrace_filter
+ # cat /sys/kernel/debug/tracing/set_ftrace_filter
hrtimer_run_queues
hrtimer_run_pending
hrtimer_init
@@ -1668,7 +1668,7 @@ hrtimer_init_sleeper
The set_ftrace_notrace prevents those functions from being
traced.
- # echo '*preempt*' '*lock*' > /debug/tracing/set_ftrace_notrace
+ # echo '*preempt*' '*lock*' > /sys/kernel/debug/tracing/set_ftrace_notrace
Produces:
@@ -1758,13 +1758,13 @@ the effect on the tracing is different. Every read from
trace_pipe is consumed. This means that subsequent reads will be
different. The trace is live.
- # echo function > /debug/tracing/current_tracer
- # cat /debug/tracing/trace_pipe > /tmp/trace.out &
+ # echo function > /sys/kernel/debug/tracing/current_tracer
+ # cat /sys/kernel/debug/tracing/trace_pipe > /tmp/trace.out &
[1] 4153
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo 1 > /sys/kernel/debug/tracing/tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > /sys/kernel/debug/tracing/tracing_enabled
+ # cat /sys/kernel/debug/tracing/trace
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1800,7 +1800,7 @@ number listed is the number of entries that can be recorded per
CPU. To know the full size, multiply the number of possible CPUS
with the number of entries.
- # cat /debug/tracing/buffer_size_kb
+ # cat /sys/kernel/debug/tracing/buffer_size_kb
1408 (units kilobytes)
Note, to modify this, you must have tracing completely disabled.
@@ -1808,18 +1808,18 @@ To do that, echo "nop" into the current_tracer. If the
current_tracer is not set to "nop", an EINVAL error will be
returned.
- # echo nop > /debug/tracing/current_tracer
- # echo 10000 > /debug/tracing/buffer_size_kb
- # cat /debug/tracing/buffer_size_kb
+ # echo nop > /sys/kernel/debug/tracing/current_tracer
+ # echo 10000 > /sys/kernel/debug/tracing/buffer_size_kb
+ # cat /sys/kernel/debug/tracing/buffer_size_kb
10000 (units kilobytes)
The number of pages which will be allocated is limited to a
percentage of available memory. Allocating too much will produce
an error.
- # echo 1000000000000 > /debug/tracing/buffer_size_kb
+ # echo 1000000000000 > /sys/kernel/debug/tracing/buffer_size_kb
-bash: echo: write error: Cannot allocate memory
- # cat /debug/tracing/buffer_size_kb
+ # cat /sys/kernel/debug/tracing/buffer_size_kb
85
-----------
diff --git a/Documentation/trace/mmiotrace.txt b/Documentation/trace/mmiotrace.txt
index 5731c67..162effb 100644
--- a/Documentation/trace/mmiotrace.txt
+++ b/Documentation/trace/mmiotrace.txt
@@ -32,41 +32,41 @@ is no way to automatically detect if you are losing events due to CPUs racing.
Usage Quick Reference
---------------------
-$ mount -t debugfs debugfs /debug
-$ echo mmiotrace > /debug/tracing/current_tracer
-$ cat /debug/tracing/trace_pipe > mydump.txt &
+$ mount -t debugfs debugfs /sys/kernel/debug
+$ echo mmiotrace > /sys/kernel/debug/tracing/current_tracer
+$ cat /sys/kernel/debug/tracing/trace_pipe > mydump.txt &
Start X or whatever.
-$ echo "X is up" > /debug/tracing/trace_marker
-$ echo nop > /debug/tracing/current_tracer
+$ echo "X is up" > /sys/kernel/debug/tracing/trace_marker
+$ echo nop > /sys/kernel/debug/tracing/current_tracer
Check for lost events.
Usage
-----
-Make sure debugfs is mounted to /debug. If not, (requires root privileges)
-$ mount -t debugfs debugfs /debug
+Make sure debugfs is mounted to /sys/kernel/debug. If not, (requires root privileges)
+$ mount -t debugfs debugfs /sys/kernel/debug
Check that the driver you are about to trace is not loaded.
Activate mmiotrace (requires root privileges):
-$ echo mmiotrace > /debug/tracing/current_tracer
+$ echo mmiotrace > /sys/kernel/debug/tracing/current_tracer
Start storing the trace:
-$ cat /debug/tracing/trace_pipe > mydump.txt &
+$ cat /sys/kernel/debug/tracing/trace_pipe > mydump.txt &
The 'cat' process should stay running (sleeping) in the background.
Load the driver you want to trace and use it. Mmiotrace will only catch MMIO
accesses to areas that are ioremapped while mmiotrace is active.
During tracing you can place comments (markers) into the trace by
-$ echo "X is up" > /debug/tracing/trace_marker
+$ echo "X is up" > /sys/kernel/debug/tracing/trace_marker
This makes it easier to see which part of the (huge) trace corresponds to
which action. It is recommended to place descriptive markers about what you
do.
Shut down mmiotrace (requires root privileges):
-$ echo nop > /debug/tracing/current_tracer
+$ echo nop > /sys/kernel/debug/tracing/current_tracer
The 'cat' process exits. If it does not, kill it by issuing 'fg' command and
pressing ctrl+c.
@@ -78,10 +78,10 @@ to view your kernel log and look for "mmiotrace has lost events" warning. If
events were lost, the trace is incomplete. You should enlarge the buffers and
try again. Buffers are enlarged by first seeing how large the current buffers
are:
-$ cat /debug/tracing/buffer_size_kb
+$ cat /sys/kernel/debug/tracing/buffer_size_kb
gives you a number. Approximately double this number and write it back, for
instance:
-$ echo 128000 > /debug/tracing/buffer_size_kb
+$ echo 128000 > /sys/kernel/debug/tracing/buffer_size_kb
Then start again from the top.
If you are doing a trace for a driver project, e.g. Nouveau, you should also
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index dc7a8c3..9aa8932 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -430,7 +430,7 @@ static void pkt_sysfs_cleanup(void)
/********************************************************************
entries in debugfs
- /debugfs/pktcdvd[0-7]/
+ /sys/kernel/debug/pktcdvd[0-7]/
info
*******************************************************************/
diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
index c77c6c6..6ce0e26 100644
--- a/drivers/gpu/drm/drm_debugfs.c
+++ b/drivers/gpu/drm/drm_debugfs.c
@@ -105,7 +105,7 @@ int drm_debugfs_create_files(struct drm_info_list *files, int count,
ent = debugfs_create_file(files[i].name, S_IFREG | S_IRUGO,
root, tmp, &drm_debugfs_fops);
if (!ent) {
- DRM_ERROR("Cannot create /debugfs/dri/%s/%s\n",
+ DRM_ERROR("Cannot create /sys/kernel/debug/dri/%s/%s\n",
name, files[i].name);
drm_free(tmp, sizeof(struct drm_info_node),
_DRM_DRIVER);
@@ -133,9 +133,9 @@ EXPORT_SYMBOL(drm_debugfs_create_files);
* \param minor device minor number
* \param root DRI debugfs dir entry.
*
- * Create the DRI debugfs root entry "/debugfs/dri", the device debugfs root entry
- * "/debugfs/dri/%minor%/", and each entry in debugfs_list as
- * "/debugfs/dri/%minor%/%name%".
+ * Create the DRI debugfs root entry "/sys/kernel/debug/dri", the device debugfs root entry
+ * "/sys/kernel/debug/dri/%minor%/", and each entry in debugfs_list as
+ * "/sys/kernel/debug/dri/%minor%/%name%".
*/
int drm_debugfs_init(struct drm_minor *minor, int minor_id,
struct dentry *root)
@@ -148,7 +148,7 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
sprintf(name, "%d", minor_id);
minor->debugfs_root = debugfs_create_dir(name, root);
if (!minor->debugfs_root) {
- DRM_ERROR("Cannot create /debugfs/dri/%s\n", name);
+ DRM_ERROR("Cannot create /sys/kernel/debug/dri/%s\n", name);
return -1;
}
@@ -165,7 +165,7 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
ret = dev->driver->debugfs_init(minor);
if (ret) {
DRM_ERROR("DRM: Driver failed to initialize "
- "/debugfs/dri.\n");
+ "/sys/kernel/debug/dri.\n");
return ret;
}
}
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 019b7c5..1bf7efd 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -339,7 +339,7 @@ static int __init drm_core_init(void)
drm_debugfs_root = debugfs_create_dir("dri", NULL);
if (!drm_debugfs_root) {
- DRM_ERROR("Cannot create /debugfs/dri\n");
+ DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
ret = -1;
goto err_p3;
}
diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index b9631e3..b2a93c4 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -328,7 +328,7 @@ static int drm_get_minor(struct drm_device *dev, struct drm_minor **minor, int t
#if defined(CONFIG_DEBUG_FS)
ret = drm_debugfs_init(new_minor, minor_id, drm_debugfs_root);
if (ret) {
- DRM_ERROR("DRM: Failed to initialize /debugfs/dri.\n");
+ DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
goto err_g2;
}
#endif
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 214a92d..a170cea 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -2200,7 +2200,7 @@ config SKGE_DEBUG
depends on SKGE && DEBUG_FS
help
This option adds the ability to dump driver state for debugging.
- The file debugfs/skge/ethX displays the state of the internal
+ The file /sys/kernel/debug/skge/ethX displays the state of the internal
transmit and receive rings.
If unsure, say N.
@@ -2226,7 +2226,7 @@ config SKY2_DEBUG
depends on SKY2 && DEBUG_FS
help
This option adds the ability to dump driver state for debugging.
- The file debugfs/sky2/ethX displays the state of the internal
+ The file /sys/kernel/debug/sky2/ethX displays the state of the internal
transmit and receive rings.
If unsure, say N.
diff --git a/drivers/net/wimax/i2400m/i2400m.h b/drivers/net/wimax/i2400m/i2400m.h
index 3ae2df3..da2e8f2 100644
--- a/drivers/net/wimax/i2400m/i2400m.h
+++ b/drivers/net/wimax/i2400m/i2400m.h
@@ -389,7 +389,7 @@ struct i2400m {
unsigned ready:1; /* all probing steps done */
unsigned rx_reorder:1; /* RX reorder is enabled */
u8 trace_msg_from_user; /* echo rx msgs to 'trace' pipe */
- /* typed u8 so debugfs/u8 can tweak */
+ /* typed u8 so /sys/kernel/debug/u8 can tweak */
enum i2400m_system_state state;
wait_queue_head_t state_wq; /* Woken up when on state updates */
diff --git a/drivers/net/wireless/ath5k/Kconfig b/drivers/net/wireless/ath5k/Kconfig
index 75383a5..fdfa708 100644
--- a/drivers/net/wireless/ath5k/Kconfig
+++ b/drivers/net/wireless/ath5k/Kconfig
@@ -27,11 +27,11 @@ config ATH5K_DEBUG
Say Y, if and you will get debug options for ath5k.
To use this, you need to mount debugfs:
- mkdir /debug/
- mount -t debugfs debug /debug/
+ mkdir /sys/kernel/debug/
+ mount -t debugfs debug /sys/kernel/debug/
You will get access to files under:
- /debug/ath5k/phy0/
+ /sys/kernel/debug/ath5k/phy0/
To enable debug, pass the debug level to the debug module
parameter. For example:
diff --git a/drivers/net/wireless/libertas/README b/drivers/net/wireless/libertas/README
index d860fc3..ab6a2d5 100644
--- a/drivers/net/wireless/libertas/README
+++ b/drivers/net/wireless/libertas/README
@@ -72,7 +72,7 @@ rdrf
location that is to be read. This parameter must be specified in
hexadecimal (its possible to preceed preceding the number with a "0x").
- Path: /debugfs/libertas_wireless/ethX/registers/
+ Path: /sys/kernel/debug/libertas_wireless/ethX/registers/
Usage:
echo "0xa123" > rdmac ; cat rdmac
@@ -95,7 +95,7 @@ wrrf
sleepparams
This command is used to set the sleepclock configurations
- Path: /debugfs/libertas_wireless/ethX/
+ Path: /sys/kernel/debug/libertas_wireless/ethX/
Usage:
cat sleepparams: reads the current sleepclock configuration
@@ -115,7 +115,7 @@ subscribed_events
The subscribed_events directory contains the interface for the
subscribed events API.
- Path: /debugfs/libertas_wireless/ethX/subscribed_events/
+ Path: /sys/kernel/debug/libertas_wireless/ethX/subscribed_events/
Each event is represented by a filename. Each filename consists of the
following three fields:
@@ -165,7 +165,7 @@ subscribed_events
extscan
This command is used to do a specific scan.
- Path: /debugfs/libertas_wireless/ethX/
+ Path: /sys/kernel/debug/libertas_wireless/ethX/
Usage: echo "SSID" > extscan
@@ -179,7 +179,7 @@ getscantable
Display the current contents of the driver scan table (ie. get the
scan results).
- Path: /debugfs/libertas_wireless/ethX/
+ Path: /sys/kernel/debug/libertas_wireless/ethX/
Usage:
cat getscantable
@@ -188,7 +188,7 @@ setuserscan
Initiate a customized scan and retrieve the results
- Path: /debugfs/libertas_wireless/ethX/
+ Path: /sys/kernel/debug/libertas_wireless/ethX/
Usage:
echo "[ARGS]" > setuserscan
diff --git a/drivers/scsi/lpfc/lpfc_debugfs.c b/drivers/scsi/lpfc/lpfc_debugfs.c
index 52be564..9112380 100644
--- a/drivers/scsi/lpfc/lpfc_debugfs.c
+++ b/drivers/scsi/lpfc/lpfc_debugfs.c
@@ -51,8 +51,8 @@
* debugfs interface
*
* To access this interface the user should:
- * # mkdir /debug
- * # mount -t debugfs none /debug
+ * # mkdir /sys/kernel/debug
+ * # mount -t debugfs none /sys/kernel/debug
*
* The lpfc debugfs directory hierarchy is:
* lpfc/lpfcX/vportY
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 883cd44..99b7aad 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -406,7 +406,7 @@ static inline char *pack_hex_byte(char *buf, u8 byte)
*
* Use tracing_on/tracing_off when you want to quickly turn on or off
* tracing. It simply enables or disables the recording of the trace events.
- * This also corresponds to the user space debugfs/tracing/tracing_on
+ * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
* file, which gives a means for the kernel and userspace to interact.
* Place a tracing_off() in the kernel where you want tracing to end.
* From user space, examine the trace, and then echo 1 > tracing_on
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index d35a7ee..9c9ac7d 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -197,7 +197,7 @@ static inline void tracepoint_synchronize_unregister(void)
* * This is how the trace record is structured and will
* * be saved into the ring buffer. These are the fields
* * that will be exposed to user-space in
- * * /debug/tracing/events/<*>/format.
+ * * /sys/kernel/debug/tracing/events/<*>/format.
* *
* * The declared 'local variable' is called '__entry'
* *
@@ -257,7 +257,7 @@ static inline void tracepoint_synchronize_unregister(void)
* tracepoint callback (this is used by programmatic plugins and
* can also by used by generic instrumentation like SystemTap), and
* it is also used to expose a structured trace record in
- * /debug/tracing/events/.
+ * /sys/kernel/debug/tracing/events/.
*/
#define TRACE_EVENT(name, proto, args, struct, assign, print) \
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 417d198..e5ce28f 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -120,7 +120,7 @@ config IRQSOFF_TRACER
disabled by default and can be runtime (re-)started
via:
- echo 0 > /debugfs/tracing/tracing_max_latency
+ echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
(Note that kernel size and overhead increases with this option
enabled. This option and the preempt-off timing option can be
@@ -141,7 +141,7 @@ config PREEMPT_TRACER
disabled by default and can be runtime (re-)started
via:
- echo 0 > /debugfs/tracing/tracing_max_latency
+ echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
(Note that kernel size and overhead increases with this option
enabled. This option and the irqs-off timing option can be
@@ -213,7 +213,7 @@ config TRACE_BRANCH_PROFILING
This tracer profiles all the the likely and unlikely macros
in the kernel. It will display the results in:
- /debugfs/tracing/profile_annotated_branch
+ /sys/kernel/debug/tracing/profile_annotated_branch
Note: this will add a significant overhead, only turn this
on if you need to profile the system's use of these macros.
@@ -228,7 +228,7 @@ config PROFILE_ALL_BRANCHES
taken in the kernel is recorded whether it hit or miss.
The results will be displayed in:
- /debugfs/tracing/profile_branch
+ /sys/kernel/debug/tracing/profile_branch
This configuration, when enabled, will impose a great overhead
on the system. This should only be enabled when the system
@@ -276,7 +276,7 @@ config STACK_TRACER
select KALLSYMS
help
This special tracer records the maximum stack footprint of the
- kernel and displays it in debugfs/tracing/stack_trace.
+ kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
This tracer works by hooking into every function call that the
kernel executes, and keeping a maximum stack depth value and
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index cda81ec..9b94d57 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -335,7 +335,7 @@ static raw_spinlock_t ftrace_max_lock =
/*
* Copy the new maximum trace into the separate maximum-trace
* structure. (this way the maximum trace is permanently saved,
- * for later retrieval via /debugfs/tracing/latency_trace)
+ * for later retrieval via /sys/kernel/debug/tracing/latency_trace)
*/
static void
__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
@@ -2366,21 +2366,21 @@ static const struct file_operations tracing_iter_fops = {
static const char readme_msg[] =
"tracing mini-HOWTO:\n\n"
- "# mkdir /debug\n"
- "# mount -t debugfs nodev /debug\n\n"
- "# cat /debug/tracing/available_tracers\n"
+ "# mkdir /sys/kernel/debug\n"
+ "# mount -t debugfs nodev /sys/kernel/debug\n\n"
+ "# cat /sys/kernel/debug/tracing/available_tracers\n"
"wakeup preemptirqsoff preemptoff irqsoff function sched_switch nop\n\n"
- "# cat /debug/tracing/current_tracer\n"
+ "# cat /sys/kernel/debug/tracing/current_tracer\n"
"nop\n"
- "# echo sched_switch > /debug/tracing/current_tracer\n"
- "# cat /debug/tracing/current_tracer\n"
+ "# echo sched_switch > /sys/kernel/debug/tracing/current_tracer\n"
+ "# cat /sys/kernel/debug/tracing/current_tracer\n"
"sched_switch\n"
- "# cat /debug/tracing/trace_options\n"
+ "# cat /sys/kernel/debug/tracing/trace_options\n"
"noprint-parent nosym-offset nosym-addr noverbose\n"
- "# echo print-parent > /debug/tracing/trace_options\n"
- "# echo 1 > /debug/tracing/tracing_enabled\n"
- "# cat /debug/tracing/trace > /tmp/trace.txt\n"
- "# echo 0 > /debug/tracing/tracing_enabled\n"
+ "# echo print-parent > /sys/kernel/debug/tracing/trace_options\n"
+ "# echo 1 > /sys/kernel/debug/tracing/tracing_enabled\n"
+ "# cat /sys/kernel/debug/tracing/trace > /tmp/trace.txt\n"
+ "# echo 0 > /sys/kernel/debug/tracing/tracing_enabled\n"
;
static ssize_t
diff --git a/scripts/tracing/draw_functrace.py b/scripts/tracing/draw_functrace.py
index 902f9a9..66f4d1b 100644
--- a/scripts/tracing/draw_functrace.py
+++ b/scripts/tracing/draw_functrace.py
@@ -12,10 +12,10 @@ calls. Only the functions's names and the the call time are provided.
Usage:
Be sure that you have CONFIG_FUNCTION_TRACER
- # mkdir /debugfs
- # mount -t debug debug /debug
- # echo function > /debug/tracing/current_tracer
- $ cat /debug/tracing/trace_pipe > ~/raw_trace_func
+ # mkdir /sys/kernel/debug
+ # mount -t debug debug /sys/kernel/debug
+ # echo function > /sys/kernel/debug/tracing/current_tracer
+ $ cat /sys/kernel/debug/tracing/trace_pipe > ~/raw_trace_func
Wait some times but not too much, the script is a bit slow.
Break the pipe (Ctrl + Z)
$ scripts/draw_functrace.py < raw_trace_func > draw_functrace
--
1.6.3.1
-----------------------------------------------
To unsubscribe from this list: send the line "unsubscribe linux-***"
in the body of a message to majo...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
GeunSik Lim ( S A M S U N G E L E C T R O N I C S )
e-Mail :1) geuns...@samsung.com
2) lee...@gmail.com , lee...@gmail.com
HomePage: http://blog.naver.com/invain/
Steven Rostedt
On Sat, 30 May 2009, GeunSik Lim wrote:
> diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
> index fd9a3e6..cbc6cca 100644
> --- a/Documentation/trace/ftrace.txt
> +++ b/Documentation/trace/ftrace.txt
> @@ -35,11 +35,11 @@ well as the files to display output.
>
> To mount the debugfs system:
>
> - # mkdir /debug
> - # mount -t debugfs nodev /debug
> + # mkdir /sys/kernel/debug
If you configure debugfs into the kernel, the directory /sys/kernel/debug
will automatically be created. Remember, /sys is a psuedo filesystem as
well.
> + # mount -t debugfs nodev /sys/kernel/debug
>
> ( Note: it is more common to mount at /sys/kernel/debug, but for
> - simplicity this document will use /debug)
> + simplicity this document will use /sys/kernel/debug)
LOL!
Egad! This is exactly why I hate the path name. It distracts so much from
the eyes to what you want to accomplish. It seems that because it is a
tradition to use this /sys/kernel/debug path, that I'm destine to fail in
my discuss for it. I will ask that this document suggest the following at
the beginning.
===
When debugfs is configured into the kernel (which selecting any ftrace
option will do) the directory /sys/kernel/debug will be created. To mount
this directory, you can add to your /etc/fstab file:
debugfs /debug debugfs defaults 0 0
Or you can mount it at run time with:
mount -t debugfs nodev /sys/kernel/debug
For quicker access to that directory you may want to make a soft link to
it:
ln -s /sys/kernel/debug /debug
Any selected ftrace option will also create a directory called tracing
within the debugfs. The rest of the document will assume that you are in
the ftrace directory (cd /sys/kernel/debugfs) and will only concentrate
on the files within that directory and not distract from the content with
the extended "/sys/kernel/debug/tracing" path name.
===
And then we can change all your other changes in this file as:
s,/sys/kernel/debug/tracing,,
-- Steve
Steven Rostedt
On Fri, 29 May 2009, Steven Rostedt wrote:
> ===
> When debugfs is configured into the kernel (which selecting any ftrace
> option will do) the directory /sys/kernel/debug will be created. To mount
> this directory, you can add to your /etc/fstab file:
>
> debugfs /debug debugfs defaults 0 0
>
> Or you can mount it at run time with:
>
> mount -t debugfs nodev /sys/kernel/debug
>
> For quicker access to that directory you may want to make a soft link to
> it:
>
> ln -s /sys/kernel/debug /debug
>
> Any selected ftrace option will also create a directory called tracing
> within the debugfs. The rest of the document will assume that you are in
> the ftrace directory (cd /sys/kernel/debugfs) and will only concentrate
s,/sys/kernel/debugfs,/sys/kernel/debug/tracing,
> on the files within that directory and not distract from the content with
> the extended "/sys/kernel/debug/tracing" path name.
> ===
-- Steve
Steven Rostedt
On Fri, 29 May 2009, Steven Rostedt wrote:
> When debugfs is configured into the kernel (which selecting any ftrace
> option will do) the directory /sys/kernel/debug will be created. To mount
> this directory, you can add to your /etc/fstab file:
>
> debugfs /debug debugfs defaults 0 0
s,/debug,/sys/kernel/debug,
>
> Or you can mount it at run time with:
>
> mount -t debugfs nodev /sys/kernel/debug
>
> For quicker access to that directory you may want to make a soft link to
> it:
>
> ln -s /sys/kernel/debug /debug
>
> Any selected ftrace option will also create a directory called tracing
> within the debugfs. The rest of the document will assume that you are in
> the ftrace directory (cd /sys/kernel/debugfs) and will only concentrate
> on the files within that directory and not distract from the content with
> the extended "/sys/kernel/debug/tracing" path name.
> ===
-- Steve
Steven Rostedt
On Sat, 30 May 2009, GeunSik Lim wrote:
>
>
> Dear Greg and Steen,
>
> Thanks your advices and opinions about a confusion according to
> too many mount directory names for debugfs. I made rfc v2 patch file again like belows.
> Can I hear your advices about below patch contents?.
>
> * ref:
> http://groups.google.com/group/linux.kernel/browse_thread/thread/c34e386587979340/dc52317f888e78b6?#dc52317f888e78b6
>
>
> Regards,
> GeunSik Lim.
>
> Subject: [PATCH] Fix terminology inconsistency of dir name to mount debugfs filesystem.
>
> Many developers use "/debug/" or "/debugfs/ directory name to mount
> debugfs filesystem for ftrace according to
> ./Documentation/tracers/ftrace.txt file.
>
> And, three directory names(ex:/debug/, /debugfs/, /sys/kernel/debug/) is
> existed in kernel source like ftrace, DRM, Wireless, Network[sky2]files
> to mount debugfs filesystem.
>
> debugfs means debug filesystem for debugging easy to use by greg kroah
> hartman. "/sys/kernel/debug/" name is suitable as directory name
> of debugfs filesystem.
> -debugfs related reference: http://lwn.net/Articles/115405/
Note, LWN has an update this week:
http://lwn.net/Articles/334546/
But it currently is subscriber only. Others would need to either buy a
subscription (plug) or wait a week for it to become open.
Still for some aspects, just having "debugfs" without the leading "/"
might just be self explanatory. We can assume the user already knows where
debugfs is mounted.
-- Steve
>
> Fix inconsistency of directory name to mount debugfs filesystem.
>
> Signed-off-by: GeunSik Lim <geuns...@samsung.com>
> Acked-By: Inaky Perez-Gonzalez <in...@linux.intel.com>
> CC: Greg KH <gr...@kroah.com>
> CC: Steven Rostedt <ros...@goodmis.org>
> CC: linux-kernel <linux-...@vger.kernel.org>
GeunSik Lim
I updated contents that you advised like belows.
If I mistake, Please correct me.
And, I also need your review about below 2 contents in the ftrace.txt file.
Thanks,
GeunSik Lim.
1)
@@ -1146,7 +1158,7 @@ int trace_fd;
[...]
int main(int argc, char *argv[]) {
[...]
- trace_fd = open("/debug/tracing/tracing_enabled", O_WRONLY);
+ trace_fd = open("/sys/kernel/debug/tracing/tracing_enabled", O_WRONLY);
[...]
if (condition_hit()) {
write(trace_fd, "0", 1);
@@ -1154,26 +1166,23 @@ int main(int argc, char *argv[]) {
[...]
}
@@ -1217,12 +1226,12 @@ int main (int argc, char **argv)
char line[64];
int s;
- ffd = open("/debug/tracing/current_tracer", O_WRONLY);
+ ffd =
open("/sys/kernel/debug/tracing/current_tracer", O_WRONLY);
if (ffd < 0)
exit(-1);
write(ffd, "nop", 3);
- fd = open("/debug/tracing/set_ftrace_pid", O_WRONLY);
+ fd = open("/sys/kernel/debug/tracing/set_ftrace_pid",
O_WRONLY);
s = sprintf(line, "%d\n", getpid());
write(fd, line, s);
-Note: Here we hard coded the path name. The debugfs mount is not
-guaranteed to be at /debug (and is more commonly at
-/sys/kernel/debug). For simple one time traces, the above is
-sufficent. For anything else, a search through /proc/mounts may
+Note: Here we hard coded the path name. A search through /proc/mounts may
be needed to find where the debugfs file-system is mounted.
2)
More details can be found in the source code, in the
-kernel/tracing/*.c files.
+kernel/trace/*.c files
* about ftrace.txt file
---
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index fd9a3e6..790199b 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -7,7 +7,6 @@ Copyright 2008 Red Hat Inc.
(dual licensed under the GPL v2)
Reviewers: Elias Oltmanns, Randy Dunlap, Andrew Morton,
John Kacur, and David Teigland.
-
Written for: 2.6.28-rc2
Introduction
@@ -33,13 +32,26 @@ The File System
Ftrace uses the debugfs file system to hold the control files as
well as the files to display output.
-To mount the debugfs system:
+When debugfs is configured into the kernel (which selecting any ftrace
+option will do) the directory /sys/kernel/debug will be created. To mount
+this directory, you can add to your /etc/fstab file:
+
+ debugfs /sys/kernel/debug debugfs defaults 0 0
+
+Or you can mount it at run time with:
+
+ mount -t debugfs nodev /sys/kernel/debug
+
+For quicker access to that directory you may want to make a soft link to
+it:
- # mkdir /debug
- # mount -t debugfs nodev /debug
+ ln -s /sys/kernel/debug /debug
-( Note: it is more common to mount at /sys/kernel/debug, but for
- simplicity this document will use /debug)
+Any selected ftrace option will also create a directory called tracing
+within the debugfs. The rest of the document will assume that you are in
+the ftrace directory (cd /sys/kernel/debug/tracing) and will only concentrate
+on the files within that directory and not distract from the content with
+the extended "/sys/kernel/debug/tracing" path name.
That's it! (assuming that you have ftrace configured into your kernel)
@@ -389,18 +401,18 @@ trace_options
The trace_options file is used to control what gets printed in
the trace output. To see what is available, simply cat the file:
- cat /debug/tracing/trace_options
+ cat ./trace_options
print-parent nosym-offset nosym-addr noverbose noraw nohex nobin \
noblock nostacktrace nosched-tree nouserstacktrace nosym-userobj
To disable one of the options, echo in the option prepended with
"no".
- echo noprint-parent > /debug/tracing/trace_options
+ echo noprint-parent > ./trace_options
To enable an option, leave off the "no".
- echo sym-offset > /debug/tracing/trace_options
+ echo sym-offset > ./trace_options
Here are the available options:
@@ -476,11 +488,11 @@ sched_switch
This tracer simply records schedule switches. Here is an example
of how to use it.
- # echo sched_switch > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo sched_switch > ./current_tracer
+ # echo 1 > ./tracing_enabled
# sleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > ./tracing_enabled
+ # cat ./trace
# tracer: sched_switch
#
@@ -574,13 +586,13 @@ new trace is saved.
To reset the maximum, echo 0 into tracing_max_latency. Here is
an example:
- # echo irqsoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo irqsoff > ./current_tracer
+ # echo 0 > ./tracing_max_latency
+ # echo 1 > ./tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > ./tracing_enabled
+ # cat ./latency_trace
# tracer: irqsoff
#
irqsoff latency trace v1.1.5 on 2.6.26
@@ -681,13 +693,13 @@ Like the irqsoff tracer, it records the maximum
latency for
which preemption was disabled. The control of preemptoff tracer
is much like the irqsoff tracer.
- # echo preemptoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo preemptoff > ./current_tracer
+ # echo 0 > ./tracing_max_latency
+ # echo 1 > ./tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > ./tracing_enabled
+ # cat ./latency_trace
# tracer: preemptoff
#
preemptoff latency trace v1.1.5 on 2.6.26-rc8
@@ -828,13 +840,13 @@ tracer.
Again, using this trace is much like the irqsoff and preemptoff
tracers.
- # echo preemptirqsoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo preemptirqsoff > ./current_tracer
+ # echo 0 > ./tracing_max_latency
+ # echo 1 > ./tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > ./tracing_enabled
+ # cat ./latency_trace
# tracer: preemptirqsoff
#
preemptirqsoff latency trace v1.1.5 on 2.6.26-rc8
@@ -990,12 +1002,12 @@ slightly differently than we did with the
previous tracers.
Instead of performing an 'ls', we will run 'sleep 1' under
'chrt' which changes the priority of the task.
- # echo wakeup > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo wakeup > ./current_tracer
+ # echo 0 > ./tracing_max_latency
+ # echo 1 > ./tracing_enabled
# chrt -f 5 sleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > ./tracing_enabled
+ # cat ./latency_trace
# tracer: wakeup
#
wakeup latency trace v1.1.5 on 2.6.26-rc8
@@ -1105,11 +1117,11 @@ can be done from the debug file system. Make sure the
ftrace_enabled is set; otherwise this tracer is a nop.
# sysctl kernel.ftrace_enabled=1
- # echo function > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo function > ./current_tracer
+ # echo 1 > ./tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > ./tracing_enabled
+ # cat ./trace
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1146,7 +1158,7 @@ int trace_fd;
[...]
int main(int argc, char *argv[]) {
[...]
- trace_fd = open("/debug/tracing/tracing_enabled", O_WRONLY);
+ trace_fd = open("/sys/kernel/debug/tracing/tracing_enabled", O_WRONLY);
[...]
if (condition_hit()) {
write(trace_fd, "0", 1);
@@ -1154,26 +1166,23 @@ int main(int argc, char *argv[]) {
[...]
}
-Note: Here we hard coded the path name. The debugfs mount is not
-guaranteed to be at /debug (and is more commonly at
-/sys/kernel/debug). For simple one time traces, the above is
-sufficent. For anything else, a search through /proc/mounts may
+Note: Here we hard coded the path name. A search through /proc/mounts may
be needed to find where the debugfs file-system is mounted.
Single thread tracing
---------------------
-By writing into /debug/tracing/set_ftrace_pid you can trace a
+By writing into ./set_ftrace_pid you can trace a
single thread. For example:
-# cat /debug/tracing/set_ftrace_pid
+# cat ./set_ftrace_pid
no pid
-# echo 3111 > /debug/tracing/set_ftrace_pid
-# cat /debug/tracing/set_ftrace_pid
+# echo 3111 > ./set_ftrace_pid
+# cat ./set_ftrace_pid
3111
-# echo function > /debug/tracing/current_tracer
-# cat /debug/tracing/trace | head
+# echo function > ./current_tracer
+# cat ./trace | head
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1184,8 +1193,8 @@ no pid
yum-updatesd-3111 [003] 1637.254683: lock_hrtimer_base
<-hrtimer_try_to_cancel
yum-updatesd-3111 [003] 1637.254685: fget_light <-do_sys_poll
yum-updatesd-3111 [003] 1637.254686: pipe_poll <-do_sys_poll
-# echo -1 > /debug/tracing/set_ftrace_pid
-# cat /debug/tracing/trace |head
+# echo -1 > ./set_ftrace_pid
+# cat ./trace |head
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1217,12 +1226,12 @@ int main (int argc, char **argv)
char line[64];
int s;
- ffd = open("/debug/tracing/current_tracer", O_WRONLY);
+ ffd =
open("/sys/kernel/debug/tracing/current_tracer", O_WRONLY);
if (ffd < 0)
exit(-1);
write(ffd, "nop", 3);
- fd = open("/debug/tracing/set_ftrace_pid", O_WRONLY);
+ fd = open("/sys/kernel/debug/tracing/set_ftrace_pid",
O_WRONLY);
s = sprintf(line, "%d\n", getpid());
write(fd, line, s);
@@ -1374,22 +1383,22 @@ want, depending on your needs.
tracing_cpu_mask file) or you might sometimes see unordered
function calls while cpu tracing switch.
- hide: echo nofuncgraph-cpu > /debug/tracing/trace_options
- show: echo funcgraph-cpu > /debug/tracing/trace_options
+ hide: echo nofuncgraph-cpu > ./trace_options
+ show: echo funcgraph-cpu > ./trace_options
- The duration (function's time of execution) is displayed on
the closing bracket line of a function or on the same line
than the current function in case of a leaf one. It is default
enabled.
- hide: echo nofuncgraph-duration > /debug/tracing/trace_options
- show: echo funcgraph-duration > /debug/tracing/trace_options
+ hide: echo nofuncgraph-duration > ./trace_options
+ show: echo funcgraph-duration > ./trace_options
- The overhead field precedes the duration field in case of
reached duration thresholds.
- hide: echo nofuncgraph-overhead > /debug/tracing/trace_options
- show: echo funcgraph-overhead > /debug/tracing/trace_options
+ hide: echo nofuncgraph-overhead > ./trace_options
+ show: echo funcgraph-overhead > ./trace_options
depends on: funcgraph-duration
ie:
@@ -1418,8 +1427,8 @@ want, depending on your needs.
- The task/pid field displays the thread cmdline and pid which
executed the function. It is default disabled.
- hide: echo nofuncgraph-proc > /debug/tracing/trace_options
- show: echo funcgraph-proc > /debug/tracing/trace_options
+ hide: echo nofuncgraph-proc > ./trace_options
+ show: echo funcgraph-proc > ./trace_options
ie:
@@ -1442,8 +1451,8 @@ want, depending on your needs.
system clock since it started. A snapshot of this time is
given on each entry/exit of functions
- hide: echo nofuncgraph-abstime > /debug/tracing/trace_options
- show: echo funcgraph-abstime > /debug/tracing/trace_options
+ hide: echo nofuncgraph-abstime > ./trace_options
+ show: echo funcgraph-abstime > ./trace_options
ie:
@@ -1540,7 +1549,7 @@ listed in:
available_filter_functions
- # cat /debug/tracing/available_filter_functions
+ # cat ./available_filter_functions
put_prev_task_idle
kmem_cache_create
pick_next_task_rt
@@ -1552,12 +1561,12 @@ mutex_lock
If I am only interested in sys_nanosleep and hrtimer_interrupt:
# echo sys_nanosleep hrtimer_interrupt \
- > /debug/tracing/set_ftrace_filter
- # echo ftrace > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ > ./set_ftrace_filter
+ # echo ftrace > ./current_tracer
+ # echo 1 > ./tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > ./tracing_enabled
+ # cat ./trace
# tracer: ftrace
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1568,7 +1577,7 @@ If I am only interested in sys_nanosleep and
hrtimer_interrupt:
To see which functions are being traced, you can cat the file:
- # cat /debug/tracing/set_ftrace_filter
+ # cat ./set_ftrace_filter
hrtimer_interrupt
sys_nanosleep
@@ -1588,7 +1597,7 @@ Note: It is better to use quotes to enclose the
wild cards,
otherwise the shell may expand the parameters into names
of files in the local directory.
- # echo 'hrtimer_*' > /debug/tracing/set_ftrace_filter
+ # echo 'hrtimer_*' > ./set_ftrace_filter
Produces:
@@ -1609,7 +1618,7 @@ Produces:
Notice that we lost the sys_nanosleep.
- # cat /debug/tracing/set_ftrace_filter
+ # cat ./set_ftrace_filter
hrtimer_run_queues
hrtimer_run_pending
hrtimer_init
@@ -1635,17 +1644,17 @@ To append to the filters, use '>>'
To clear out a filter so that all functions will be recorded
again:
- # echo > /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo > ./set_ftrace_filter
+ # cat ./set_ftrace_filter
#
Again, now we want to append.
- # echo sys_nanosleep > /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo sys_nanosleep > ./set_ftrace_filter
+ # cat ./set_ftrace_filter
sys_nanosleep
- # echo 'hrtimer_*' >> /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo 'hrtimer_*' >> ./set_ftrace_filter
+ # cat ./set_ftrace_filter
hrtimer_run_queues
hrtimer_run_pending
hrtimer_init
@@ -1668,7 +1677,7 @@ hrtimer_init_sleeper
The set_ftrace_notrace prevents those functions from being
traced.
- # echo '*preempt*' '*lock*' > /debug/tracing/set_ftrace_notrace
+ # echo '*preempt*' '*lock*' > ./set_ftrace_notrace
Produces:
@@ -1758,13 +1767,13 @@ the effect on the tracing is different. Every read from
trace_pipe is consumed. This means that subsequent reads will be
different. The trace is live.
- # echo function > /debug/tracing/current_tracer
- # cat /debug/tracing/trace_pipe > /tmp/trace.out &
+ # echo function > ./current_tracer
+ # cat ./trace_pipe > /tmp/trace.out &
[1] 4153
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo 1 > ./tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > ./tracing_enabled
+ # cat ./trace
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1800,7 +1809,7 @@ number listed is the number of entries that can
be recorded per
CPU. To know the full size, multiply the number of possible CPUS
with the number of entries.
- # cat /debug/tracing/buffer_size_kb
+ # cat ./buffer_size_kb
1408 (units kilobytes)
Note, to modify this, you must have tracing completely disabled.
@@ -1808,21 +1817,21 @@ To do that, echo "nop" into the current_tracer. If the
current_tracer is not set to "nop", an EINVAL error will be
returned.
- # echo nop > /debug/tracing/current_tracer
- # echo 10000 > /debug/tracing/buffer_size_kb
- # cat /debug/tracing/buffer_size_kb
+ # echo nop > ./current_tracer
+ # echo 10000 > ./buffer_size_kb
+ # cat ./buffer_size_kb
10000 (units kilobytes)
The number of pages which will be allocated is limited to a
percentage of available memory. Allocating too much will produce
an error.
- # echo 1000000000000 > /debug/tracing/buffer_size_kb
+ # echo 1000000000000 > ./buffer_size_kb
-bash: echo: write error: Cannot allocate memory
- # cat /debug/tracing/buffer_size_kb
+ # cat ./buffer_size_kb
85
---
--
Regards,
GeunSik Lim ( SAMSUNG ELECTRONICS)
Blog : http://blog.naver.com/invain/
e-Mail: geuns...@samsung.com
lee...@gmail.com , lee...@gmail.com
Steven Rostedt
Here's the function I use:
#define _STR(x) x
#define STR(x) _STR(x)
#define MAX_PATH 256
const char *find_debugfs(void)
{
static char debugfs[MAX_PATH+1];
static int debugfs_found;
char type[100];
FILE *fp;
if (debugfs_found)
return debugfs;
if ((fp = fopen("/proc/mounts","r")) == NULL) {
perror("/proc/mounts");
return NULL;
}
while (fscanf(fp, "%*s %"
STR(MAX_PATH)
"s %99s %*s %*d %*d\n",
debugfs, type) == 2) {
if (strcmp(type, "debugfs") == 0)
break;
}
fclose(fp);
if (strcmp(type, "debugfs") != 0) {
fprintf(stderr, "debugfs not mounted");
return NULL;
}
debugfs_found = 1;
return debugfs;
}
This might be a good idea to show it. This is the most robust since it
does not hard code the debugfs directory.
Please remove the "./", it is also distracting. We state that we "cd" to
the location. "cat trace_options" is good enough.
Same for the all the others below.
Also, since I'm the most picky about this, you may want to remove the
ftrace files from the patch and move it to another patch. That way the
owners of the other files can ack them and get those changes in. When we
have something for ftrace, I'll give my ack. But lets not hold up the
other changes because of me ;-)
-- Steve
GeunSik Lim
Default directory is "/sys/kernel/debug/tracing" in ftrace.txt file
as you mentioned.
I will append below code for "***/tracing/" directory name.
int size;
[...]
size = MAX_PATH - strlen(debugfs);
strncat(debugfs, "/tracing/", size);
return debugfs;
It's right. This is just my private style. I will remove "./".
>
> Same for the all the others below.
>
> Also, since I'm the most picky about this, you may want to remove the
> ftrace files from the patch and move it to another patch. That way the
I am not think that you are the most picky about this. I like your advice and
review about my proposal for consensus.
> owners of the other files can ack them and get those changes in. When we
> have something for ftrace, I'll give my ack. But lets not hold up the
> other changes because of me ;-)
>
Don't care. Hope it helps. ;-)
I will modify ftrace files from the patch according to your advice.
GeunSik Lim
>> Also, since I'm the most picky about this, you may want to remove the
>> ftrace files from the patch and move it to another patch. That way the
> I am not think that you are the most picky about this. I like your advice and
> review about my proposal for consensus.
>> owners of the other files can ack them and get those changes in. When we
>> have something for ftrace, I'll give my ack. But lets not hold up the
>> other changes because of me ;-)
>>
> Don't care. Hope it helps. ;-)
> I will modify ftrace files from the patch according to your advice.
I updated ftrace related contents according to Steven's help like belows.
If I misunderstood wrongly, Please correct me.
Thanks.
* About ftrace.txt file/
---
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index fd9a3e6..caaf5d9 100644
- cat /debug/tracing/trace_options
+ cat trace_options
print-parent nosym-offset nosym-addr noverbose noraw nohex nobin \
noblock nostacktrace nosched-tree nouserstacktrace nosym-userobj
To disable one of the options, echo in the option prepended with
"no".
- echo noprint-parent > /debug/tracing/trace_options
+ echo noprint-parent > trace_options
To enable an option, leave off the "no".
- echo sym-offset > /debug/tracing/trace_options
+ echo sym-offset > trace_options
Here are the available options:
@@ -476,11 +488,11 @@ sched_switch
This tracer simply records schedule switches. Here is an example
of how to use it.
- # echo sched_switch > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo sched_switch > current_tracer
+ # echo 1 > tracing_enabled
# sleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > tracing_enabled
+ # cat trace
# tracer: sched_switch
#
@@ -574,13 +586,13 @@ new trace is saved.
To reset the maximum, echo 0 into tracing_max_latency. Here is
an example:
- # echo irqsoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo irqsoff > current_tracer
+ # echo 0 > tracing_max_latency
+ # echo 1 > tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > tracing_enabled
+ # cat latency_trace
# tracer: irqsoff
#
irqsoff latency trace v1.1.5 on 2.6.26
@@ -681,13 +693,13 @@ Like the irqsoff tracer, it records the maximum
latency for
which preemption was disabled. The control of preemptoff tracer
is much like the irqsoff tracer.
- # echo preemptoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo preemptoff > current_tracer
+ # echo 0 > tracing_max_latency
+ # echo 1 > tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > tracing_enabled
+ # cat latency_trace
# tracer: preemptoff
#
preemptoff latency trace v1.1.5 on 2.6.26-rc8
@@ -828,13 +840,13 @@ tracer.
Again, using this trace is much like the irqsoff and preemptoff
tracers.
- # echo preemptirqsoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo preemptirqsoff > current_tracer
+ # echo 0 > tracing_max_latency
+ # echo 1 > tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > tracing_enabled
+ # cat latency_trace
# tracer: preemptirqsoff
#
preemptirqsoff latency trace v1.1.5 on 2.6.26-rc8
@@ -990,12 +1002,12 @@ slightly differently than we did with the
previous tracers.
Instead of performing an 'ls', we will run 'sleep 1' under
'chrt' which changes the priority of the task.
- # echo wakeup > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo wakeup > current_tracer
+ # echo 0 > tracing_max_latency
+ # echo 1 > tracing_enabled
# chrt -f 5 sleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > tracing_enabled
+ # cat latency_trace
# tracer: wakeup
#
wakeup latency trace v1.1.5 on 2.6.26-rc8
@@ -1105,11 +1117,11 @@ can be done from the debug file system. Make sure the
ftrace_enabled is set; otherwise this tracer is a nop.
# sysctl kernel.ftrace_enabled=1
- # echo function > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo function > current_tracer
+ # echo 1 > tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > tracing_enabled
+ # cat trace
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1146,7 +1158,7 @@ int trace_fd;
[...]
int main(int argc, char *argv[]) {
[...]
- trace_fd = open("/debug/tracing/tracing_enabled", O_WRONLY);
+ trace_fd = open(find_debugfs("tracing_enabled"), O_WRONLY);
[...]
if (condition_hit()) {
write(trace_fd, "0", 1);
@@ -1154,26 +1166,20 @@ int main(int argc, char *argv[]) {
[...]
}
-Note: Here we hard coded the path name. The debugfs mount is not
-guaranteed to be at /debug (and is more commonly at
-/sys/kernel/debug). For simple one time traces, the above is
-sufficent. For anything else, a search through /proc/mounts may
-be needed to find where the debugfs file-system is mounted.
-
Single thread tracing
---------------------
-By writing into /debug/tracing/set_ftrace_pid you can trace a
+By writing into set_ftrace_pid you can trace a
single thread. For example:
-# cat /debug/tracing/set_ftrace_pid
+# cat set_ftrace_pid
no pid
-# echo 3111 > /debug/tracing/set_ftrace_pid
-# cat /debug/tracing/set_ftrace_pid
+# echo 3111 > set_ftrace_pid
+# cat set_ftrace_pid
3111
-# echo function > /debug/tracing/current_tracer
-# cat /debug/tracing/trace | head
+# echo function > current_tracer
+# cat trace | head
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1184,8 +1190,8 @@ no pid
yum-updatesd-3111 [003] 1637.254683: lock_hrtimer_base
<-hrtimer_try_to_cancel
yum-updatesd-3111 [003] 1637.254685: fget_light <-do_sys_poll
yum-updatesd-3111 [003] 1637.254686: pipe_poll <-do_sys_poll
-# echo -1 > /debug/tracing/set_ftrace_pid
-# cat /debug/tracing/trace |head
+# echo -1 > set_ftrace_pid
+# cat trace |head
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1202,11 +1208,57 @@ something like this simple program:
#include <stdio.h>
#include <stdlib.h>
+#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
+#define _STR(x) #x
+#define STR(x) _STR(x)
+#define MAX_PATH 256
+
+const char *find_debugfs(char *file_name)
+{
+ static char debugfs[MAX_PATH+1];
+ static int debugfs_found;
+ char type[100];
+ FILE *fp;
+ int size;
+
+ if (debugfs_found)
+ return debugfs;
+
+ if ((fp = fopen("/proc/mounts","r")) == NULL) {
+ perror("/proc/mounts");
+ return NULL;
+ }
+
+ while (fscanf(fp, "%*s %"
+ STR(MAX_PATH)
+ "s %99s %*s %*d %*d\n",
+ debugfs, type) == 2) {
+ if (strcmp(type, "debugfs") == 0)
+ break;
+ }
+ fclose(fp);
+
+ if (strcmp(type, "debugfs") != 0) {
+ fprintf(stderr, "debugfs not mounted");
+ return NULL;
+ }
+
+ debugfs_found = 1;
+
+ size = MAX_PATH - strlen(debugfs);
+ strncat(debugfs, "/tracing/", size);
+
+ size = MAX_PATH - strlen(debugfs);
+ strncat(debugfs, file_name, size);
+
+ return debugfs;
+}
+
int main (int argc, char **argv)
{
if (argc < 1)
@@ -1217,12 +1269,12 @@ int main (int argc, char **argv)
char line[64];
int s;
- ffd = open("/debug/tracing/current_tracer", O_WRONLY);
+ ffd = open(find_debugfs("current_tracer"), O_WRONLY);
if (ffd < 0)
exit(-1);
write(ffd, "nop", 3);
- fd = open("/debug/tracing/set_ftrace_pid", O_WRONLY);
+ fd = open(find_debugfs("set_ftrace_pid"), O_WRONLY);
s = sprintf(line, "%d\n", getpid());
write(fd, line, s);
@@ -1374,22 +1426,22 @@ want, depending on your needs.
tracing_cpu_mask file) or you might sometimes see unordered
function calls while cpu tracing switch.
- hide: echo nofuncgraph-cpu > /debug/tracing/trace_options
- show: echo funcgraph-cpu > /debug/tracing/trace_options
+ hide: echo nofuncgraph-cpu > trace_options
+ show: echo funcgraph-cpu > trace_options
- The duration (function's time of execution) is displayed on
the closing bracket line of a function or on the same line
than the current function in case of a leaf one. It is default
enabled.
- hide: echo nofuncgraph-duration > /debug/tracing/trace_options
- show: echo funcgraph-duration > /debug/tracing/trace_options
+ hide: echo nofuncgraph-duration > trace_options
+ show: echo funcgraph-duration > trace_options
- The overhead field precedes the duration field in case of
reached duration thresholds.
- hide: echo nofuncgraph-overhead > /debug/tracing/trace_options
- show: echo funcgraph-overhead > /debug/tracing/trace_options
+ hide: echo nofuncgraph-overhead > trace_options
+ show: echo funcgraph-overhead > trace_options
depends on: funcgraph-duration
ie:
@@ -1418,8 +1470,8 @@ want, depending on your needs.
- The task/pid field displays the thread cmdline and pid which
executed the function. It is default disabled.
- hide: echo nofuncgraph-proc > /debug/tracing/trace_options
- show: echo funcgraph-proc > /debug/tracing/trace_options
+ hide: echo nofuncgraph-proc > trace_options
+ show: echo funcgraph-proc > trace_options
ie:
@@ -1442,8 +1494,8 @@ want, depending on your needs.
system clock since it started. A snapshot of this time is
given on each entry/exit of functions
- hide: echo nofuncgraph-abstime > /debug/tracing/trace_options
- show: echo funcgraph-abstime > /debug/tracing/trace_options
+ hide: echo nofuncgraph-abstime > trace_options
+ show: echo funcgraph-abstime > trace_options
ie:
@@ -1540,7 +1592,7 @@ listed in:
available_filter_functions
- # cat /debug/tracing/available_filter_functions
+ # cat available_filter_functions
put_prev_task_idle
kmem_cache_create
pick_next_task_rt
@@ -1552,12 +1604,12 @@ mutex_lock
If I am only interested in sys_nanosleep and hrtimer_interrupt:
# echo sys_nanosleep hrtimer_interrupt \
- > /debug/tracing/set_ftrace_filter
- # echo ftrace > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ > set_ftrace_filter
+ # echo ftrace > current_tracer
+ # echo 1 > tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > tracing_enabled
+ # cat trace
# tracer: ftrace
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1568,7 +1620,7 @@ If I am only interested in sys_nanosleep and
hrtimer_interrupt:
To see which functions are being traced, you can cat the file:
- # cat /debug/tracing/set_ftrace_filter
+ # cat set_ftrace_filter
hrtimer_interrupt
sys_nanosleep
@@ -1588,7 +1640,7 @@ Note: It is better to use quotes to enclose the
wild cards,
otherwise the shell may expand the parameters into names
of files in the local directory.
- # echo 'hrtimer_*' > /debug/tracing/set_ftrace_filter
+ # echo 'hrtimer_*' > set_ftrace_filter
Produces:
@@ -1609,7 +1661,7 @@ Produces:
Notice that we lost the sys_nanosleep.
- # cat /debug/tracing/set_ftrace_filter
+ # cat set_ftrace_filter
hrtimer_run_queues
hrtimer_run_pending
hrtimer_init
@@ -1635,17 +1687,17 @@ To append to the filters, use '>>'
To clear out a filter so that all functions will be recorded
again:
- # echo > /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo > set_ftrace_filter
+ # cat set_ftrace_filter
#
Again, now we want to append.
- # echo sys_nanosleep > /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo sys_nanosleep > set_ftrace_filter
+ # cat set_ftrace_filter
sys_nanosleep
- # echo 'hrtimer_*' >> /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo 'hrtimer_*' >> set_ftrace_filter
+ # cat set_ftrace_filter
hrtimer_run_queues
hrtimer_run_pending
hrtimer_init
@@ -1668,7 +1720,7 @@ hrtimer_init_sleeper
The set_ftrace_notrace prevents those functions from being
traced.
- # echo '*preempt*' '*lock*' > /debug/tracing/set_ftrace_notrace
+ # echo '*preempt*' '*lock*' > set_ftrace_notrace
Produces:
@@ -1758,13 +1810,13 @@ the effect on the tracing is different. Every read from
trace_pipe is consumed. This means that subsequent reads will be
different. The trace is live.
- # echo function > /debug/tracing/current_tracer
- # cat /debug/tracing/trace_pipe > /tmp/trace.out &
+ # echo function > current_tracer
+ # cat trace_pipe > /tmp/trace.out &
[1] 4153
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo 1 > tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > tracing_enabled
+ # cat trace
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1800,7 +1852,7 @@ number listed is the number of entries that can
be recorded per
CPU. To know the full size, multiply the number of possible CPUS
with the number of entries.
- # cat /debug/tracing/buffer_size_kb
+ # cat buffer_size_kb
1408 (units kilobytes)
Note, to modify this, you must have tracing completely disabled.
@@ -1808,18 +1860,18 @@ To do that, echo "nop" into the current_tracer. If the
current_tracer is not set to "nop", an EINVAL error will be
returned.
- # echo nop > /debug/tracing/current_tracer
- # echo 10000 > /debug/tracing/buffer_size_kb
- # cat /debug/tracing/buffer_size_kb
+ # echo nop > current_tracer
+ # echo 10000 > buffer_size_kb
+ # cat buffer_size_kb
10000 (units kilobytes)
The number of pages which will be allocated is limited to a
percentage of available memory. Allocating too much will produce
an error.
- # echo 1000000000000 > /debug/tracing/buffer_size_kb
+ # echo 1000000000000 > buffer_size_kb
-bash: echo: write error: Cannot allocate memory
- # cat /debug/tracing/buffer_size_kb
+ # cat buffer_size_kb
85
---
Regards,
GeunSik Lim ( SAMSUNG ELECTRONICS)
Blog : http://blog.naver.com/invain/
e-Mail: geuns...@samsung.com
lee...@gmail.com , lee...@gmail.com
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
Steven Rostedt
Heh, I usually have another function to add the /tracing part. But sure,
we could do that too.
-- Steve
Steven Rostedt
On Sat, 30 May 2009, GeunSik Lim wrote:
You need to make two functions. One to find the debugfs and one to add the
file. The "debugfs_found" will make the function return just the first
file_name every time. Something like this: (remove the file_name from
find_debugfs).
const char *tracing_file(const char *file_name)
{
static char trace_file[MAX_PATH+1];
snprintf(trace_file, MAX_PATH, "%s/%s", find_debugfs(), file_name);
return trace_file;
}
The above is not thread safe, but is OK for non threaded programs.
-- Steve
> +
> + return debugfs;
> +}
> +
> int main (int argc, char **argv)
> {
> if (argc < 1)
> @@ -1217,12 +1269,12 @@ int main (int argc, char **argv)
> char line[64];
> int s;
>
> - ffd = open("/debug/tracing/current_tracer", O_WRONLY);
> + ffd = open(find_debugfs("current_tracer"), O_WRONLY);
> if (ffd < 0)
> exit(-1);
> write(ffd, "nop", 3);
>
> - fd = open("/debug/tracing/set_ftrace_pid", O_WRONLY);
> + fd = open(find_debugfs("set_ftrace_pid"), O_WRONLY);
> s = sprintf(line, "%d\n", getpid());
> write(fd, line, s);
>
GeunSik Lim
> You need to make two functions. One to find the debugfs and one to add the
> file. The "debugfs_found" will make the function return just the first
> file_name every time. Something like this: (remove the file_name from
> find_debugfs).
>
> const char *tracing_file(const char *file_name)
> {
> static char trace_file[MAX_PATH+1];
>
> snprintf(trace_file, MAX_PATH, "%s/%s", find_debugfs(), file_name);
>
> return trace_file;
> }
>
> The above is not thread safe, but is OK for non threaded programs.
I modified pseudo code using tracing_file function that you sent.
* ftrace.txt info after modification.
---
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index fd9a3e6..05f8378 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -7,7 +7,6 @@ Copyright 2008 Red Hat Inc.
(dual licensed under the GPL v2)
Reviewers: Elias Oltmanns, Randy Dunlap, Andrew Morton,
John Kacur, and David Teigland.
-
Written for: 2.6.28-rc2
Introduction
@@ -33,13 +32,26 @@ The File System
Ftrace uses the debugfs file system to hold the control files as
well as the files to display output.
-To mount the debugfs system:
+When debugfs is configured into the kernel (which selecting any ftrace
+option will do) the directory /sys/kernel/debug will be created. To mount
+this directory, you can add to your /etc/fstab file:
+
+ debugfs /sys/kernel/debug debugfs defaults 0 0
+
+Or you can mount it at run time with:
+
+ mount -t debugfs nodev /sys/kernel/debug
- # mkdir /debug
- # mount -t debugfs nodev /debug
+For quicker access to that directory you may want to make a soft link to
+it:
-( Note: it is more common to mount at /sys/kernel/debug, but for
- simplicity this document will use /debug)
+ ln -s /sys/kernel/debug /debug
+
+ trace_fd = open(tracing_file("tracing_enabled"), O_WRONLY);
Single thread tracing
---------------------
@@ -1207,6 +1213,51 @@ something like this simple program:
#include <fcntl.h>
#include <unistd.h>
+#define _STR(x) #x
+#define STR(x) _STR(x)
+#define MAX_PATH 256
+
+const char *find_debugfs(void)
+{
+ static char debugfs[MAX_PATH+1];
+ static int debugfs_found;
+ char type[100];
+ FILE *fp;
+
+ if (debugfs_found)
+ return debugfs;
+
+ if ((fp = fopen("/proc/mounts","r")) == NULL) {
+ perror("/proc/mounts");
+ return NULL;
+ }
+
+ while (fscanf(fp, "%*s %"
+ STR(MAX_PATH)
+ "s %99s %*s %*d %*d\n",
+ debugfs, type) == 2) {
+ if (strcmp(type, "debugfs") == 0)
+ break;
+ }
+ fclose(fp);
+
+ if (strcmp(type, "debugfs") != 0) {
+ fprintf(stderr, "debugfs not mounted");
+ return NULL;
+ }
+
+ debugfs_found = 1;
+
+ return debugfs;
+}
+
+const char *tracing_file(const char *file_name)
+{
+ static char trace_file[MAX_PATH+1];
+ snprintf(trace_file, MAX_PATH, "%s/%s", find_debugfs(), file_name);
+ return trace_file;
+}
+
int main (int argc, char **argv)
{
if (argc < 1)
@@ -1217,12 +1268,12 @@ int main (int argc, char **argv)
char line[64];
int s;
- ffd = open("/debug/tracing/current_tracer", O_WRONLY);
+ ffd = open(tracing_file("current_tracer"), O_WRONLY);
if (ffd < 0)
exit(-1);
write(ffd, "nop", 3);
- fd = open("/debug/tracing/set_ftrace_pid", O_WRONLY);
+ fd = open(tracing_file("set_ftrace_pid"), O_WRONLY);
s = sprintf(line, "%d\n", getpid());
write(fd, line, s);
@@ -1374,22 +1425,22 @@ want, depending on your needs.
tracing_cpu_mask file) or you might sometimes see unordered
function calls while cpu tracing switch.
- hide: echo nofuncgraph-cpu > /debug/tracing/trace_options
- show: echo funcgraph-cpu > /debug/tracing/trace_options
+ hide: echo nofuncgraph-cpu > trace_options
+ show: echo funcgraph-cpu > trace_options
- The duration (function's time of execution) is displayed on
the closing bracket line of a function or on the same line
than the current function in case of a leaf one. It is default
enabled.
- hide: echo nofuncgraph-duration > /debug/tracing/trace_options
- show: echo funcgraph-duration > /debug/tracing/trace_options
+ hide: echo nofuncgraph-duration > trace_options
+ show: echo funcgraph-duration > trace_options
- The overhead field precedes the duration field in case of
reached duration thresholds.
- hide: echo nofuncgraph-overhead > /debug/tracing/trace_options
- show: echo funcgraph-overhead > /debug/tracing/trace_options
+ hide: echo nofuncgraph-overhead > trace_options
+ show: echo funcgraph-overhead > trace_options
depends on: funcgraph-duration
ie:
@@ -1418,8 +1469,8 @@ want, depending on your needs.
- The task/pid field displays the thread cmdline and pid which
executed the function. It is default disabled.
- hide: echo nofuncgraph-proc > /debug/tracing/trace_options
- show: echo funcgraph-proc > /debug/tracing/trace_options
+ hide: echo nofuncgraph-proc > trace_options
+ show: echo funcgraph-proc > trace_options
ie:
@@ -1442,8 +1493,8 @@ want, depending on your needs.
system clock since it started. A snapshot of this time is
given on each entry/exit of functions
- hide: echo nofuncgraph-abstime > /debug/tracing/trace_options
- show: echo funcgraph-abstime > /debug/tracing/trace_options
+ hide: echo nofuncgraph-abstime > trace_options
+ show: echo funcgraph-abstime > trace_options
ie:
@@ -1540,7 +1591,7 @@ listed in:
available_filter_functions
- # cat /debug/tracing/available_filter_functions
+ # cat available_filter_functions
put_prev_task_idle
kmem_cache_create
pick_next_task_rt
@@ -1552,12 +1603,12 @@ mutex_lock
If I am only interested in sys_nanosleep and hrtimer_interrupt:
# echo sys_nanosleep hrtimer_interrupt \
- > /debug/tracing/set_ftrace_filter
- # echo ftrace > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ > set_ftrace_filter
+ # echo ftrace > current_tracer
+ # echo 1 > tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > tracing_enabled
+ # cat trace
# tracer: ftrace
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1568,7 +1619,7 @@ If I am only interested in sys_nanosleep and
hrtimer_interrupt:
To see which functions are being traced, you can cat the file:
- # cat /debug/tracing/set_ftrace_filter
+ # cat set_ftrace_filter
hrtimer_interrupt
sys_nanosleep
@@ -1588,7 +1639,7 @@ Note: It is better to use quotes to enclose the
wild cards,
otherwise the shell may expand the parameters into names
of files in the local directory.
- # echo 'hrtimer_*' > /debug/tracing/set_ftrace_filter
+ # echo 'hrtimer_*' > set_ftrace_filter
Produces:
@@ -1609,7 +1660,7 @@ Produces:
Notice that we lost the sys_nanosleep.
- # cat /debug/tracing/set_ftrace_filter
+ # cat set_ftrace_filter
hrtimer_run_queues
hrtimer_run_pending
hrtimer_init
@@ -1635,17 +1686,17 @@ To append to the filters, use '>>'
To clear out a filter so that all functions will be recorded
again:
- # echo > /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo > set_ftrace_filter
+ # cat set_ftrace_filter
#
Again, now we want to append.
- # echo sys_nanosleep > /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo sys_nanosleep > set_ftrace_filter
+ # cat set_ftrace_filter
sys_nanosleep
- # echo 'hrtimer_*' >> /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo 'hrtimer_*' >> set_ftrace_filter
+ # cat set_ftrace_filter
hrtimer_run_queues
hrtimer_run_pending
hrtimer_init
@@ -1668,7 +1719,7 @@ hrtimer_init_sleeper
The set_ftrace_notrace prevents those functions from being
traced.
- # echo '*preempt*' '*lock*' > /debug/tracing/set_ftrace_notrace
+ # echo '*preempt*' '*lock*' > set_ftrace_notrace
Produces:
@@ -1758,13 +1809,13 @@ the effect on the tracing is different. Every read from
trace_pipe is consumed. This means that subsequent reads will be
different. The trace is live.
- # echo function > /debug/tracing/current_tracer
- # cat /debug/tracing/trace_pipe > /tmp/trace.out &
+ # echo function > current_tracer
+ # cat trace_pipe > /tmp/trace.out &
[1] 4153
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo 1 > tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > tracing_enabled
+ # cat trace
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1800,7 +1851,7 @@ number listed is the number of entries that can
be recorded per
CPU. To know the full size, multiply the number of possible CPUS
with the number of entries.
- # cat /debug/tracing/buffer_size_kb
+ # cat buffer_size_kb
1408 (units kilobytes)
Note, to modify this, you must have tracing completely disabled.
@@ -1808,18 +1859,18 @@ To do that, echo "nop" into the current_tracer. If the
current_tracer is not set to "nop", an EINVAL error will be
returned.
- # echo nop > /debug/tracing/current_tracer
- # echo 10000 > /debug/tracing/buffer_size_kb
- # cat /debug/tracing/buffer_size_kb
+ # echo nop > current_tracer
+ # echo 10000 > buffer_size_kb
+ # cat buffer_size_kb
10000 (units kilobytes)
The number of pages which will be allocated is limited to a
percentage of available memory. Allocating too much will produce
an error.
- # echo 1000000000000 > /debug/tracing/buffer_size_kb
+ # echo 1000000000000 > buffer_size_kb
-bash: echo: write error: Cannot allocate memory
- # cat /debug/tracing/buffer_size_kb
+ # cat buffer_size_kb
85
---
--
Regards,
GeunSik Lim ( SAMSUNG ELECTRONICS)
Blog : http://blog.naver.com/invain/
e-Mail: geuns...@samsung.com
lee...@gmail.com , lee...@gmail.com
GeunSik Lim
Dear Greg and Steven,
Thanks your advices and opinions about a confusion according to
too many mount directory names for debugfs filesystem.
I made rfc v3 like belows thanks to steven and greg.
Can I hear your advices and comments about below patch contents?
* LKML about rfc v2:
http://lkml.org/lkml/2009/5/29/219
* LKML about rfc v1:
http://lkml.org/lkml/2009/5/26/17
Regards,
GeunSik Lim.
Subject: [PATCH] Fix terminology inconsistency of dir name to mount debugfs filesystem.
Many developers use "/debug/" or "/debugfs/ directory name to mount
debugfs filesystem for ftrace according to
./Documentation/tracers/ftrace.txt file.
And, three directory names(ex:/debug/, /debugfs/, /sys/kernel/debug/) is
existed in kernel source like ftrace, DRM, Wireless, Documentation,
Network[sky2]files to mount debugfs filesystem.
debugfs means debug filesystem for debugging easy to use by greg kroah
hartman. "/sys/kernel/debug/" name is suitable as directory name
of debugfs filesystem.
-debugfs related reference: http://lwn.net/Articles/334546/
Fix inconsistency of directory name to mount debugfs filesystem.
Signed-off-by: GeunSik Lim <geuns...@samsung.com>
Acked-by : Inaky Perez-Gonzalez <in...@linux.intel.com>
Reviewed-by : Steven Rostedt <ros...@goodmis.org>
Reviewed-by : Greg KH <gr...@kroah.com>
CC: Jiri Kosina <tri...@kernel.org>
CC: David Airlie <air...@linux.ie>
CC: Peter Osterlund <pet...@telia.com>
CC: James Smart <james...@emulex.com>
CC: Ananth N Mavinakayanahalli <ana...@in.ibm.com>
CC: Anil S Keshavamurthy <anil.s.kes...@intel.com>
CC: Masami Hiramatsu <mhir...@redhat.com>
CC: linux-kernel <linux-...@vger.kernel.org>
---
Documentation/DocBook/debugobjects.tmpl | 2 +-
Documentation/cdrom/packet-writing.txt | 2 +-
Documentation/fault-injection/fault-injection.txt | 70 +++---
Documentation/kprobes.txt | 6 +-
Documentation/trace/ftrace.txt | 233 +++++++++++++--------
Documentation/trace/mmiotrace.txt | 26 ++--
drivers/block/pktcdvd.c | 2 +-
drivers/gpu/drm/drm_debugfs.c | 12 +-
drivers/gpu/drm/drm_drv.c | 2 +-
drivers/gpu/drm/drm_stub.c | 2 +-
drivers/net/Kconfig | 4 +-
drivers/net/wimax/i2400m/i2400m.h | 2 +-
drivers/net/wireless/ath5k/Kconfig | 6 +-
drivers/net/wireless/libertas/README | 12 +-
drivers/scsi/lpfc/lpfc_debugfs.c | 4 +-
include/linux/kernel.h | 2 +-
include/linux/tracepoint.h | 4 +-
kernel/trace/Kconfig | 10 +-
kernel/trace/trace.c | 24 +-
scripts/tracing/draw_functrace.py | 8 +-
20 files changed, 242 insertions(+), 191 deletions(-)
index fd9a3e6..05f8378 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -7,7 +7,6 @@ Copyright 2008 Red Hat Inc.
(dual licensed under the GPL v2)
Reviewers: Elias Oltmanns, Randy Dunlap, Andrew Morton,
John Kacur, and David Teigland.
-
Written for: 2.6.28-rc2
Introduction
@@ -33,13 +32,26 @@ The File System
Ftrace uses the debugfs file system to hold the control files as
well as the files to display output.
-To mount the debugfs system:
+When debugfs is configured into the kernel (which selecting any ftrace
+option will do) the directory /sys/kernel/debug will be created. To mount
+this directory, you can add to your /etc/fstab file:
+
+ debugfs /sys/kernel/debug debugfs defaults 0 0
+
+Or you can mount it at run time with:
+
+ mount -t debugfs nodev /sys/kernel/debug
- # mkdir /debug
- # mount -t debugfs nodev /debug
+For quicker access to that directory you may want to make a soft link to
+it:
-( Note: it is more common to mount at /sys/kernel/debug, but for
- simplicity this document will use /debug)
+ ln -s /sys/kernel/debug /debug
+
+Any selected ftrace option will also create a directory called tracing
+within the debugfs. The rest of the document will assume that you are in
+the ftrace directory (cd /sys/kernel/debug/tracing) and will only concentrate
+on the files within that directory and not distract from the content with
+the extended "/sys/kernel/debug/tracing" path name.
That's it! (assuming that you have ftrace configured into your kernel)
@@ -389,18 +401,18 @@ trace_options
The trace_options file is used to control what gets printed in
the trace output. To see what is available, simply cat the file:
- cat /debug/tracing/trace_options
+ cat trace_options
print-parent nosym-offset nosym-addr noverbose noraw nohex nobin \
noblock nostacktrace nosched-tree nouserstacktrace nosym-userobj
To disable one of the options, echo in the option prepended with
"no".
- echo noprint-parent > /debug/tracing/trace_options
+ echo noprint-parent > trace_options
To enable an option, leave off the "no".
- echo sym-offset > /debug/tracing/trace_options
+ echo sym-offset > trace_options
Here are the available options:
@@ -476,11 +488,11 @@ sched_switch
This tracer simply records schedule switches. Here is an example
of how to use it.
- # echo sched_switch > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo sched_switch > current_tracer
+ # echo 1 > tracing_enabled
# sleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > tracing_enabled
+ # cat trace
# tracer: sched_switch
#
@@ -574,13 +586,13 @@ new trace is saved.
To reset the maximum, echo 0 into tracing_max_latency. Here is
an example:
- # echo irqsoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo irqsoff > current_tracer
+ # echo 0 > tracing_max_latency
+ # echo 1 > tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > tracing_enabled
+ # cat latency_trace
# tracer: irqsoff
#
irqsoff latency trace v1.1.5 on 2.6.26
@@ -681,13 +693,13 @@ Like the irqsoff tracer, it records the maximum latency for
which preemption was disabled. The control of preemptoff tracer
is much like the irqsoff tracer.
- # echo preemptoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo preemptoff > current_tracer
+ # echo 0 > tracing_max_latency
+ # echo 1 > tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > tracing_enabled
+ # cat latency_trace
# tracer: preemptoff
#
preemptoff latency trace v1.1.5 on 2.6.26-rc8
@@ -828,13 +840,13 @@ tracer.
Again, using this trace is much like the irqsoff and preemptoff
tracers.
- # echo preemptirqsoff > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo preemptirqsoff > current_tracer
+ # echo 0 > tracing_max_latency
+ # echo 1 > tracing_enabled
# ls -ltr
[...]
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > tracing_enabled
+ # cat latency_trace
# tracer: preemptirqsoff
#
preemptirqsoff latency trace v1.1.5 on 2.6.26-rc8
@@ -990,12 +1002,12 @@ slightly differently than we did with the previous tracers.
Instead of performing an 'ls', we will run 'sleep 1' under
'chrt' which changes the priority of the task.
- # echo wakeup > /debug/tracing/current_tracer
- # echo 0 > /debug/tracing/tracing_max_latency
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo wakeup > current_tracer
+ # echo 0 > tracing_max_latency
+ # echo 1 > tracing_enabled
# chrt -f 5 sleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/latency_trace
+ # echo 0 > tracing_enabled
+ # cat latency_trace
# tracer: wakeup
#
wakeup latency trace v1.1.5 on 2.6.26-rc8
@@ -1105,11 +1117,11 @@ can be done from the debug file system. Make sure the
ftrace_enabled is set; otherwise this tracer is a nop.
# sysctl kernel.ftrace_enabled=1
- # echo function > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo function > current_tracer
+ # echo 1 > tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > tracing_enabled
+ # cat trace
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1146,7 +1158,7 @@ int trace_fd;
[...]
int main(int argc, char *argv[]) {
[...]
- trace_fd = open("/debug/tracing/tracing_enabled", O_WRONLY);
+ trace_fd = open(tracing_file("tracing_enabled"), O_WRONLY);
[...]
if (condition_hit()) {
write(trace_fd, "0", 1);
@@ -1154,26 +1166,20 @@ int main(int argc, char *argv[]) {
[...]
}
-Note: Here we hard coded the path name. The debugfs mount is not
-guaranteed to be at /debug (and is more commonly at
-/sys/kernel/debug). For simple one time traces, the above is
-sufficent. For anything else, a search through /proc/mounts may
-be needed to find where the debugfs file-system is mounted.
-
Single thread tracing
---------------------
-By writing into /debug/tracing/set_ftrace_pid you can trace a
+By writing into set_ftrace_pid you can trace a
single thread. For example:
-# cat /debug/tracing/set_ftrace_pid
+# cat set_ftrace_pid
no pid
-# echo 3111 > /debug/tracing/set_ftrace_pid
-# cat /debug/tracing/set_ftrace_pid
+# echo 3111 > set_ftrace_pid
+# cat set_ftrace_pid
3111
-# echo function > /debug/tracing/current_tracer
-# cat /debug/tracing/trace | head
+# echo function > current_tracer
+# cat trace | head
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1184,8 +1190,8 @@ no pid
yum-updatesd-3111 [003] 1637.254683: lock_hrtimer_base <-hrtimer_try_to_cancel
yum-updatesd-3111 [003] 1637.254685: fget_light <-do_sys_poll
yum-updatesd-3111 [003] 1637.254686: pipe_poll <-do_sys_poll
-# echo -1 > /debug/tracing/set_ftrace_pid
-# cat /debug/tracing/trace |head
+# echo -1 > set_ftrace_pid
+# cat trace |head
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
int main (int argc, char **argv)
{
if (argc < 1)
@@ -1217,12 +1268,12 @@ int main (int argc, char **argv)
char line[64];
int s;
- ffd = open("/debug/tracing/current_tracer", O_WRONLY);
+ ffd = open(tracing_file("current_tracer"), O_WRONLY);
if (ffd < 0)
exit(-1);
write(ffd, "nop", 3);
- fd = open("/debug/tracing/set_ftrace_pid", O_WRONLY);
+ fd = open(tracing_file("set_ftrace_pid"), O_WRONLY);
s = sprintf(line, "%d\n", getpid());
write(fd, line, s);
@@ -1374,22 +1425,22 @@ want, depending on your needs.
tracing_cpu_mask file) or you might sometimes see unordered
function calls while cpu tracing switch.
- hide: echo nofuncgraph-cpu > /debug/tracing/trace_options
- show: echo funcgraph-cpu > /debug/tracing/trace_options
+ hide: echo nofuncgraph-cpu > trace_options
+ show: echo funcgraph-cpu > trace_options
- The duration (function's time of execution) is displayed on
the closing bracket line of a function or on the same line
than the current function in case of a leaf one. It is default
enabled.
- hide: echo nofuncgraph-duration > /debug/tracing/trace_options
- show: echo funcgraph-duration > /debug/tracing/trace_options
+ hide: echo nofuncgraph-duration > trace_options
+ show: echo funcgraph-duration > trace_options
- The overhead field precedes the duration field in case of
reached duration thresholds.
- hide: echo nofuncgraph-overhead > /debug/tracing/trace_options
- show: echo funcgraph-overhead > /debug/tracing/trace_options
+ hide: echo nofuncgraph-overhead > trace_options
+ show: echo funcgraph-overhead > trace_options
depends on: funcgraph-duration
ie:
@@ -1418,8 +1469,8 @@ want, depending on your needs.
- The task/pid field displays the thread cmdline and pid which
executed the function. It is default disabled.
- hide: echo nofuncgraph-proc > /debug/tracing/trace_options
- show: echo funcgraph-proc > /debug/tracing/trace_options
+ hide: echo nofuncgraph-proc > trace_options
+ show: echo funcgraph-proc > trace_options
ie:
@@ -1442,8 +1493,8 @@ want, depending on your needs.
system clock since it started. A snapshot of this time is
given on each entry/exit of functions
- hide: echo nofuncgraph-abstime > /debug/tracing/trace_options
- show: echo funcgraph-abstime > /debug/tracing/trace_options
+ hide: echo nofuncgraph-abstime > trace_options
+ show: echo funcgraph-abstime > trace_options
ie:
@@ -1540,7 +1591,7 @@ listed in:
available_filter_functions
- # cat /debug/tracing/available_filter_functions
+ # cat available_filter_functions
put_prev_task_idle
kmem_cache_create
pick_next_task_rt
@@ -1552,12 +1603,12 @@ mutex_lock
If I am only interested in sys_nanosleep and hrtimer_interrupt:
# echo sys_nanosleep hrtimer_interrupt \
- > /debug/tracing/set_ftrace_filter
- # echo ftrace > /debug/tracing/current_tracer
- # echo 1 > /debug/tracing/tracing_enabled
+ > set_ftrace_filter
+ # echo ftrace > current_tracer
+ # echo 1 > tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > tracing_enabled
+ # cat trace
# tracer: ftrace
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1568,7 +1619,7 @@ If I am only interested in sys_nanosleep and hrtimer_interrupt:
To see which functions are being traced, you can cat the file:
- # cat /debug/tracing/set_ftrace_filter
+ # cat set_ftrace_filter
hrtimer_interrupt
sys_nanosleep
@@ -1588,7 +1639,7 @@ Note: It is better to use quotes to enclose the wild cards,
otherwise the shell may expand the parameters into names
of files in the local directory.
- # echo 'hrtimer_*' > /debug/tracing/set_ftrace_filter
+ # echo 'hrtimer_*' > set_ftrace_filter
Produces:
@@ -1609,7 +1660,7 @@ Produces:
Notice that we lost the sys_nanosleep.
- # cat /debug/tracing/set_ftrace_filter
+ # cat set_ftrace_filter
hrtimer_run_queues
hrtimer_run_pending
hrtimer_init
@@ -1635,17 +1686,17 @@ To append to the filters, use '>>'
To clear out a filter so that all functions will be recorded
again:
- # echo > /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo > set_ftrace_filter
+ # cat set_ftrace_filter
#
Again, now we want to append.
- # echo sys_nanosleep > /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo sys_nanosleep > set_ftrace_filter
+ # cat set_ftrace_filter
sys_nanosleep
- # echo 'hrtimer_*' >> /debug/tracing/set_ftrace_filter
- # cat /debug/tracing/set_ftrace_filter
+ # echo 'hrtimer_*' >> set_ftrace_filter
+ # cat set_ftrace_filter
hrtimer_run_queues
hrtimer_run_pending
hrtimer_init
@@ -1668,7 +1719,7 @@ hrtimer_init_sleeper
The set_ftrace_notrace prevents those functions from being
traced.
- # echo '*preempt*' '*lock*' > /debug/tracing/set_ftrace_notrace
+ # echo '*preempt*' '*lock*' > set_ftrace_notrace
Produces:
@@ -1758,13 +1809,13 @@ the effect on the tracing is different. Every read from
trace_pipe is consumed. This means that subsequent reads will be
different. The trace is live.
- # echo function > /debug/tracing/current_tracer
- # cat /debug/tracing/trace_pipe > /tmp/trace.out &
+ # echo function > current_tracer
+ # cat trace_pipe > /tmp/trace.out &
[1] 4153
- # echo 1 > /debug/tracing/tracing_enabled
+ # echo 1 > tracing_enabled
# usleep 1
- # echo 0 > /debug/tracing/tracing_enabled
- # cat /debug/tracing/trace
+ # echo 0 > tracing_enabled
+ # cat trace
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
@@ -1800,7 +1851,7 @@ number listed is the number of entries that can be recorded per
CPU. To know the full size, multiply the number of possible CPUS
with the number of entries.
- # cat /debug/tracing/buffer_size_kb
+ # cat buffer_size_kb
1408 (units kilobytes)
Note, to modify this, you must have tracing completely disabled.
@@ -1808,18 +1859,18 @@ To do that, echo "nop" into the current_tracer. If the
current_tracer is not set to "nop", an EINVAL error will be
returned.
- # echo nop > /debug/tracing/current_tracer
- # echo 10000 > /debug/tracing/buffer_size_kb
- # cat /debug/tracing/buffer_size_kb
+ # echo nop > current_tracer
+ # echo 10000 > buffer_size_kb
+ # cat buffer_size_kb
10000 (units kilobytes)
The number of pages which will be allocated is limited to a
percentage of available memory. Allocating too much will produce
an error.
- # echo 1000000000000 > /debug/tracing/buffer_size_kb
+ # echo 1000000000000 > buffer_size_kb
-bash: echo: write error: Cannot allocate memory
- # cat /debug/tracing/buffer_size_kb
+ # cat buffer_size_kb
GeunSik Lim
Dear Greg and Steven,
This is debugfs's mount directory related patch files.
Please, merge my patch. Any Comment?
I read ./linux-2.6.git/MAINTAINERS file to submit debugfs related this patch file.
But, I don't know a maintainer about this patch exactly.
Um... If I mistake, Please, correct me.
Thanks,
Subject: [PATCH V1] Fix terminology inconsistency of dir name to mount debugfs filesystem.
Many developers use "/debug/" or "/debugfs/" or "/sys/kernel/debug/"
directory name to mount debugfs filesystem for ftrace according to
./Documentation/tracers/ftrace.txt file.
And, three directory names(ex:/debug/, /debugfs/, /sys/kernel/debug/) is
existed in kernel source like ftrace, DRM, Wireless, Documentation,
Network[sky2]files to mount debugfs filesystem.
debugfs means debug filesystem for debugging easy to use by greg kroah
hartman. "/sys/kernel/debug/" name is suitable as directory name
of debugfs filesystem.
- debugfs related reference: http://lwn.net/Articles/334546/
Fix inconsistency of directory name to mount debugfs filesystem.
* From Steven Rostedt
- find_debugfs() and tracing_files() in this patch.
Signed-off-by: GeunSik Lim <geuns...@samsung.com>
Acked-by : Inaky Perez-Gonzalez <in...@linux.intel.com>
Reviewed-by : Steven Rostedt <ros...@goodmis.org>
Reviewed-by : Greg KH <gr...@kroah.com>
Reviewed-by : James Smart <james...@emulex.com>
CC: Jiri Kosina <tri...@kernel.org>
CC: David Airlie <air...@linux.ie>
CC: Peter Osterlund <pet...@telia.com>
GeunSik Lim ( Samsung Electronics )