[Samba] hanging smbd(s) revisited

[Matt Johnson]

Hi,

Just to add -- our fcntl locking issue is on Linux, we've seen it on 
2.6.9, 2.6.13.1 and 2.6.15.3, running Mandrake 10.2. locking.tdb is on a 
local disk. All smbd child processes are blocked on apparently the same 
fcntl when it happens.

Cheers

Matt

On Sat, 25 Feb 2006, Gerald (Jerry) Carter wrote:

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> William Jojo wrote:
>
>> filemon summary shows fd 3 with 250MB/s for a process
>> that's not running any more and IBM cannot tell me why that
>> happens. (we're  AIX 5.2 TL-08-1 and 3.0.21b) So that's why
>> I haven't been that suspicious of Samba.
>
> I wonder if this is an fcntl wake up bug like the only
> that was previously found on Solaris.
>
> Jeremy/Tridge, I can't remember which file it was in
> samba.org/~tridge/junkcode.  Can you help me out?
>
>> If Jerry or Jeremy can make a suggestion of what to look for,
>> I'll set it up on my end as well. We don't have Samba
>> actually *stop*, it's just *reeeeealy* slow and context
>> switches go fromabout 8-20k/sec(with 120k
>> syscalls) to over 60k/sec (with only 30k syscalls).
>
> This sounds really similar to me.  It was a kernel bug
> on solaris when waking up processes waiting on a byte
> range lock.
>
>> The other noticeable trait is the time it takes to
>> stop smbd. If I didn't know any better, I'd swear they are
>> trying to unravel some seriously nested stack of calls or
>> complex pieces of data. It takes almost two minutes for
>> all the smbd's to clear out after stopping from SWAT.
>
> This is normal.  smbd handles signals in band so the we
> receive the TERM signal and then schedule the shutdown
> when we get done with what we are doing.
>
>
>
>
>
> cheers, jerry
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-- 
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Matt Johnson <mwj at doc.ic.ac.uk>               (020) 7594 8440 / x48440
Systems Programmer, Computing Support Group         Office: Huxley 225
Department of Computing, Imperial College London
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