Re: OOM problems on 2.6.12-rc1 with many fsx tests

[Andrew Morton <akpm@osdl.org>]

Mingming Cao <cmm@us.ibm.com> wrote:
>
> I run into OOM problem again on 2.6.12-rc1. I run some(20) fsx tests on
> 2.6.12-rc1 kernel(and 2.6.11-mm4) on ext3 filesystem, after about 10
> hours the system hit OOM, and OOM keep killing processes one by one. I
> could reproduce this problem very constantly on a 2 way PIII 700MHZ with
> 512MB RAM. Also the problem could be reproduced on running the same test
> on reiser fs.
> 
> The fsx command is:
> 
> ./fsx -c 10 -n -r 4096 -w 4096 /mnt/test/foo1 &

I was able to reproduce this on ext3.  Seven instances of the above leaked
10-15MB over 10 hours.  All of it permanently stuck on the LRU.

I'll continue to poke at it - see what kernel it started with, which
filesystems it affects, whether it happens on UP&&!PREEMPT, etc.  Not a
quick process.

Given that you also saw it on reiserfs, it might be a bug in the core
mmap/truncate/unmap handling.  We'll see.

> I also see fsx tests start to generating report about read bad data
> about the tests have run for about 9 hours(one hour before of the OOM
> happen). 

I haven't noticed anything like that.