Relate I/O's activity to processes

[Spendius]

Hi,

The guy here
http://rootshell.be/~yong321/freeware/pio1_3_c.txt
wrote a small C prg that easily allows you to see what
processes perform strong I/O's, and to further troubleshoot
eventual waits caused by this process activity. It's helped
me in a few cases to point out database problems.

But this code is only relevant to Solaris operating system:
I'd like to know if you could help me to adapt it to HPUX
operating system.
As you'll see this code rests upon the psinfo files located
in /proc/<PID> directories. Is there a similar (and simple
too) way to get at processes I/O activity within these 3
operating systems as well ?

Thanks a lot !

[Christof Meerwald]

On 8 Nov 2006 01:27:02 -0800, Spendius wrote:
> The guy here
> http://rootshell.be/~yong321/freeware/pio1_3_c.txt

[...]

> But this code is only relevant to Solaris operating system:
> I'd like to know if you could help me to adapt it to HPUX
> operating system.

Have a look at the pstat APIs:

/*
* This structure contains per-process information
*/
struct __pst_status {
[...]
_T_ULONG_T pst_majorfaults; /* # page faults needing disk
access */
[...]
_T_LONG_T pst_inblock; /* block input operations */
_T_LONG_T pst_oublock; /* block output operations */
[...]

Christof

--
http://cmeerw.org sip:cmeerw at cmeerw.org
mailto:cmeerw at cmeerw.org xmpp:cmeerw at cmeerw.org

[yon...@yahoo.com]

Christof Meerwald wrote:
> ...

> Have a look at the pstat APIs:
>
> /*
> * This structure contains per-process information
> */
> struct __pst_status {
> [...]
> _T_ULONG_T pst_majorfaults; /* # page faults needing disk
> access */
> [...]
> _T_LONG_T pst_inblock; /* block input operations */
> _T_LONG_T pst_oublock; /* block output operations */
> [...]
>
>
> Christof
>
> --
> http://cmeerw.org sip:cmeerw at cmeerw.org
> mailto:cmeerw at cmeerw.org xmpp:cmeerw at cmeerw.org

Hi, Christof,

I checked pst_inblock and pst_oublock with a small program. They seem
to always have the same values 2147479776 and 2147479780, respectively,
for all processes at any time. I just found somebody else had the same
problem:

http://www.unix.com/archive/index.php/t-15529.html

Do you have any idea? Thanks.

My server is:
HP-UX td176 B.11.23 U ia64 1928826293 unlimited-user license

Yong Huang

[Don Morris]

yon...@yahoo.com wrote:
> Christof Meerwald wrote:
>> ...
>> Have a look at the pstat APIs:
>>
>> /*
>> * This structure contains per-process information
>> */
>> struct __pst_status {
>> [...]
>> _T_ULONG_T pst_majorfaults; /* # page faults needing disk
>> access */
>> [...]
>> _T_LONG_T pst_inblock; /* block input operations */
>> _T_LONG_T pst_oublock; /* block output operations */
>> [...]
>>
>>
>> Christof
>>
>> --
>> http://cmeerw.org sip:cmeerw at cmeerw.org
>> mailto:cmeerw at cmeerw.org xmpp:cmeerw at cmeerw.org
>
> Hi, Christof,
>
> I checked pst_inblock and pst_oublock with a small program. They seem
> to always have the same values 2147479776 and 2147479780, respectively,
> for all processes at any time. I just found somebody else had the same
> problem:

Those look awfully 32-bit. Did you compile 32-bit and not use
-D_PSTAT64? There's so many things that get misreported if you don't
that this is officially unsupported. (From the pstat man page):

The use of the pstat functional interfaces for applications using the
ILP32 programming model without defining the -D_PSTAT64 compiler flag
is deprecated. Furthermore, some pstat functions are available only
for applications using the LP64 programming model and for
applications
written in standard C and extended ANSI C that use the ILP32
programming model and that define -D_PSTAT64. The pstat functions
pstat_getlwp(), pstat_getcrashinfo(), and pstat_getlocality() are
some
of the pstat functions that fall into this category.

Don

[yon...@yahoo.com]

Thanks, Don. I tried gcc (3.4.3) and cc (/usr/bin/cc, cc: HP C/aC++
B3910B A.06.12 [Aug 17 2006]) with and without -D_PSTAT64. All generate
binary successfully but each binary shows the same inblock and oublock
values for all processes, even though between with and without the
flag, they show slightly different values.

/house/yong321>cc test.c
/house/yong321>./a.out -p $$
InBlock Ops: 2147479808 ; OuBlocks: 2147479812

/house/yong321>cc -D_PSTAT64 test.c
/house/yong321>./a.out -p $$
InBlock Ops: 2147479744 ; OuBlocks: 2147479752

/house/yong321>./a.out -p 1
InBlock Ops: 2147479744 ; OuBlocks: 2147479752

Yong Huang

[Don Morris]

yon...@yahoo.com wrote:
>
> Thanks, Don. I tried gcc (3.4.3) and cc (/usr/bin/cc, cc: HP C/aC++
> B3910B A.06.12 [Aug 17 2006]) with and without -D_PSTAT64. All generate
> binary successfully but each binary shows the same inblock and oublock
> values for all processes, even though between with and without the
> flag, they show slightly different values.
>
> /house/yong321>cc test.c
> /house/yong321>./a.out -p $$
> InBlock Ops: 2147479808 ; OuBlocks: 2147479812
>
> /house/yong321>cc -D_PSTAT64 test.c
> /house/yong321>./a.out -p $$
> InBlock Ops: 2147479744 ; OuBlocks: 2147479752
>
> /house/yong321>./a.out -p 1
> InBlock Ops: 2147479744 ; OuBlocks: 2147479752

Hmm... I can't duplicate it here -- though I don't have your exact
environment, so that may be an issue.

Can you post your code -- or try with a really dirt simple program?

Here's my sample (obviously you parse your args for a target pid -
but you're likely not far off...):

# cat inblock_test.c
#include <stdlib.h>
#include <string.h>
#include <sys/pstat.h>

int
main(int argc, char *argv[])
{
struct pst_status pst;
register struct pst_status *psp = &pst;
int count;

(void)memset((void *)psp, -1, sizeof(*psp));
count = pstat_getproc(psp, sizeof(*psp), 0UL, (int)getpid());

if ( count == 0 ) {
printf("Oddness: Couldn't locate ourselves?\n");
exit(EXIT_FAILURE);
}

printf("pst_inblock: %llx, pst_oublock: %llx.\n",
psp->pst_inblock, psp->pst_oublock);
exit(EXIT_SUCCESS);
}
# cc +DD32 -D_PSTAT64 -o inblock_test inblock_test.c
# ./inblock_test
pst_inblock: 0, pst_oublock: 3.

Don

[yon...@yahoo.com]

Thanks, Don. Here's my code cut down from a bigger program:

/house/yong321>cat test.c
#include <stdio.h>
#include <sys/pstat.h>

void probe_one(pid_t);

main(int argc, char **argv)
{
pid_t pid;
int i;
while ((i = getopt(argc, argv, "HhnAp:")) != EOF)
{ switch(i)
{ case 'p':
pid = atoi(optarg);
break;
}
}

if (pid)
probe_one(pid);
}

void probe_one(pid_t pid)
{
struct pst_status pst;

if (pstat_getproc(&pst, sizeof(pst), (size_t)0, pid) != -1)
printf("InBlock Ops: %lu ; OuBlocks: %lu \n", &pst.pst_inblock,
&pst.pst_oublock);
else
perror("pstat_getproc");
}
/house/yong321>cc +DD32 -D_PSTAT64 test.c

/house/yong321>./a.out -p $$
InBlock Ops: 2147479744 ; OuBlocks: 2147479752
/house/yong321>./a.out -p 1
InBlock Ops: 2147479744 ; OuBlocks: 2147479752

/house/yong321>uname -a

HP-UX td176 B.11.23 U ia64 1928826293 unlimited-user license

The server is td176.testdrive.hp.com [15.170.178.176]. Everybody can
apply for a free account.

When I run your code, I get two 0's:

/house/yong321>./inblock_test
pst_inblock: 0, pst_oublock: 0.

Thanks again for your help.

Yong Huang

[Don Morris]

yon...@yahoo.com wrote:
> if (pstat_getproc(&pst, sizeof(pst), (size_t)0, pid) != -1)
> printf("InBlock Ops: %lu ; OuBlocks: %lu \n", &pst.pst_inblock,
> &pst.pst_oublock);

Whoops! There's your problem, man. You want to print pst.pst_inblock
and pst.pst_oublock -- not their address (well, unless you're just
really really into seeing where on the stack your compiler puts your
local addresses...). Remove the '&' character before them.

Don

[yon...@yahoo.com]

My eyes crossed when reading and copying Examples 4 and 5 in `man
pstat`. Thanks for correction. I'm writing my topio freeware program.
I'll give credit to those who helped.

Yong Huang

[yon...@yahoo.com]

yon...@yahoo.com wrote:
...

> pstat`. Thanks for correction. I'm writing my topio freeware program.
> I'll give credit to those who helped.
>
> Yong Huang

Don and others, when you have time, take a quick look at

http://rootshell.be/~yong321/freeware/pio.html#hpux

Any comments are very welcome. Thanks.

Yong Huang