Re: OOM problems with 2.6.11-rc4

["Sean" <seanlkml@sympatico.ca>]

On Tue, March 15, 2005 3:44 pm, Noah Meyerhans said:
> Hello.  We have a server, currently running 2.6.11-rc4, that is
> experiencing similar OOM problems to those described at
> http://groups-beta.google.com/group/fa.linux.kernel/msg/9633559fea029f6e
> and discussed further by several developers here (the summary is at
> http://www.kerneltraffic.org/kernel-traffic/kt20050212_296.html#6)  We
> are running 2.6.11-rc4 because it contains the patches that Andrea
> mentioned in the kerneltraffic link.  The problem was present in 2.6.10
> as well.  We can try newer 2.6 kernels if it helps.
>
> The machine in question is a dual Xeon system with 2 GB of RAM, 3.5 GB
> of swap, and several TB of NFS exported filesystems.  One notable point
> is that this machine has been running in overcommit mode 2
> (/proc/sys/vm/overcommit_memory = 2) and the OOM killer is still being
> triggered, which is allegedly not supposed to be possible according to
> the kerneltraffic.org document above.  We had been running in overcommit
> mode 0 until about a month ago, and experienced similar OOM problems
> then as well.

We're seeing this on our dual Xeon box too, with 4 GB of RAM and 2GB of
swap (no NFS) using stock RHEL 4 kernel.   The only thing that seems to
keep it from happening is setting /proc/sys/vm/vfs_cache_pressure to
10000.

Sean