Sleeping processes

[Geir Wettland]

I am trying to take a backup of my system, but as you can see from my ps
command it is sleeping:

F S UID PID PPID C PRI NI ADDR SZ WCHAN TTY TIME COMD

1 S 0 22026 22023 0 168 20 47d2580 657 68fa8000 ttys0 2:12 fbackup

Reading the man page for ps I learn that the WCHAN coloumn says what event
the process is waiting for.

My question is simply:
What is event 68fa8000 and where do I find some more information about the issue?

Thanks in advance,
Geir Wettland.

[Ken Mintz]

> F S UID PID PPID C PRI NI ADDR SZ WCHAN TTY TIME COMD
> 1 S 0 22026 22023 0 168 20 47d2580 657 68fa8000 ttys0 2:12 fbackup

> What is event 68fa8000 and where do I find some more information about the
> issue?

WCHAN is usually simply the address of an internal kernel data structure.

We can use adb on the kernel to determine the name of the structure (if
it is not allocated dynamically), but the name is often meaningful only
to a development engineer who is familiar with internal kernel algorithms.
If the structure is allocated dynamically (for example, a socket buffer),
any name that adb might yield is meaningless.

In terms of understanding what is happening, it is often useful to see
the kernel stack trace for the process. Unfortunately, that is not
obtained easily.

-- Ken Mintz

DISCLAIMER: Comments and opinions expressed are my own. They do not
represent Hewlett-Packard Company.

[Paul Hite]

In article <431...@hpindda.cup.hp.com>, mi...@hpindda.cup.hp.com (Ken Mintz) writes:
> > F S UID PID PPID C PRI NI ADDR SZ WCHAN TTY TIME COMD
> > 1 S 0 22026 22023 0 168 20 47d2580 657 68fa8000 ttys0 2:12 fbackup
> > What is event 68fa8000 and where do I find some more information about the
> > issue?
>
> WCHAN is usually simply the address of an internal kernel data structure.
>
> We can use adb on the kernel to determine the name of the structure (if
> it is not allocated dynamically), but the name is often meaningful only
> to a development engineer who is familiar with internal kernel algorithms.

You can use glance to decode the WCHAN address:
rwhod 105 1 154 root 0.0/ 0.1% 90ms 0.8/ 0.5 36 SOCKT
sh 23819 23796 158 smc 0.0/ 0.1% 10ms 0.0/ 0.0 72 SLEEP
sh 23793 23790 158 smc 0.0/ 0.0% 20ms 0.0/ 0.0 76 SLEEP
statdaemon 3 0 128 root 2.5/ 2.1% 2880ms 0.0/ 0.0 na SYS
swapper 0 0 128 root 0.0/ 0.1% 90ms 0.4/ 0.0 na MBUF
syncer 46 1 168 root 1.3/ 0.1% 140ms 6.7/ 1.3 24 SLEEP
syslogd 75 1 154 root 0.0/ 0.0% 0ms 0.0/ 0.0 64 SLEEP
vi 23772 19475 156 dave 0.0/ 0.2% 300ms 0.0/ 0.1 228 TERM
^^^^^
|
This is the decoded WCHAN field -----

I believe the glance is the only tool on HP-UX that does this. I obtained the
source code for the latest BSD ps from uunet. It decodes the WCHAN field by
default and a -n can be used to get the actual address. It would be very nice
if someone could port that to HP-UX.

Paul Hite PRC Realty Systems McLean,Va pa...@prcrs.prc.com (703) 556-2243
"We are trying to bring up an Air Traffic Control display on an X window
terminal and there seems to be some problems." -- from comp.windows.x