Subject: Re: Consistent vnlock dead locks in low memory conditions
To: Manuel Bouyer <bouyer@antioche.eu.org>
From: Stephen Jones <smj@cirr.com>
List: tech-net
Date: 06/22/2006 14:57:30
On Jun 22, 2006, at 2:15 PM, Manuel Bouyer wrote:
>
> Depends on RAM available, and other things I guess
>
>> Would that really cause a deadlock?
>
> in my experience, yes.
What sort of 'other things' and can you please tell me more about
your experiences?
>
> If you didn't change the default value then it's probably OK.
They usually all show up as allocated in systat within a few hours of
the
system running no matter what the setting is set to. Is that
probably OK too?
>> BUFCACHE I have set to 6 (%) in the kernel, can that be set
>> via sysctl as well?
>
> Yes, it's vm.bufcache.
What I really meant to ask is it dynamic though? Can it only be
increased without a reboot
or drop to single user mode?
> If it's a NFS server it doens't matter; this is for clients.
This particular server is an NFS client as well. I typically see
vnlock deadlocks
on clients and rarely on a server. However, this case is a bit of
exception as it only
has one served file system and its nfsd are the first to deadlock.