Norman Gaywood wrote:
>
> I think I have a trigger for a VM bug in the RH kernel-bigmem-2.4.18-18
>
> 16GB
> ...
> tar cf /dev/tape .
>
This machine will die due to buffer_heads which are attached
to highmem pagecache, and due to inodes which are pinned by
highmem pagecache.
> ...
> while [ `expr $COUNT - 1` != 0 ]
> do
> date
> # 2000 by 1_000_000 seems to be a 1.8G process
> perl -e '$i=2000;while ($i--){ $a[$i]="x"x1_000_000; }' &
> ...
This will evict the highmem pagecache. That frees the buffer_heads
and unpins the inodes.
> So what do I do now?
I guess talk to Red Hat. These are well-known problems and there
should be fixes for them in a "bigmem" kernel.
Otherwise, the -aa kernels have patches to address these problems.
One option would be to roll your own kernel, based on a kernel.org
kernel and a matching patch from
http://www.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/
> ...
> Anyone have some patches for me to
> try that won't take me too far from the RH 8.0 base system.
Hard. The relevant patches are:
http://www.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.20aa1/05_vm_16_active_free_zone_bhs-1
and
http://www.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.20aa1/10_inode-highmem-2
The first one will not come vaguely close to applying to an
RH 2.4.18 kernel.
The second one may well apply, and will probably fix the problem.
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This archive was generated by hypermail 2b29 : Sat Dec 07 2002 - 22:00:25 EST