From: Cohen, Andy (Andy.Cohen@cognex.com)
Date: Mon Feb 23 2004 - 13:15:20 EST
SUMMARY
=======
Turns out it was due to a known bug. I did receive alot of very informative replies about how memory works and the like much of which was over my head but interesting none-the-less.
The gist of the problem is that the hung process will stay hung forever (until the system is rebooted). The latest patchkit (#6 for 5.1A) fixed the problem.
This email from Whitney Latta says it all:
The processes are waiting for a lock on an anonymous memory object... and will wait forever for "something" to unset the lbit. The problem is, this may never happen!
As luck would have it, this issue has been seen and resolved in patchkits for V5.1A... kit#5 and higher (which is why I recommended the patchkit loaded be included in the message). If you already have patchkit#5/6 installed, then this may be a new variation of this issue, and will need to be brought to the attention of HP Services and Tru64 Unix engineering.
Here is the description of the fix (note, a further symptom of this problem is that panics could also occur under certain circumstances). This patch will fix the hanging "ps", as well.
========================================================================
PROBLEM: (94036) (PATCH ID: OSF520-861)
********
When running in lockmode 0 (which is normal for uniprocessor machines), the
locking package ended up patching out the wrong routine. This led to
a_lock related panics.
========================================================================
Note the problem occurs when running in "lockmode 0", which is the nominal lock state for uniprocessor systems, like this as800. The "lockmode" parameter, set in the "generic:" stanza of sysconfigtab, sets up the SMP locking package on the system... and, at boottime, patches out the lock routines based on this setting. (lockmode=2 is standard SMP locking for multiprocessor systems).
Unfortunately, this will do nothing for the current problem of hanging commands, but will eliminate exposure to it in the future. So, to address the current issue, a reboot will be necessary (the anon_lock will never complete on its own!).
If the patchkit is not current, then I recommend installing the latest patchkit available online (pk#6 for V5.1A).
Thanks everybody!
Andy
ORIGINAL QUESTION
=================
Hi,
When we're logged in as root and issue a 'ps' nothing happens - it just hangs. I can't kill them -- they won't die. We're running 5.1A on an AS 800. Have I exhausted some process limit?
Thanks,
Andy
p.s. -- I don't see anything in /var/adm/messages or uerf.
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