Re: Mem issues in 2.6.9 (ever since 2.6.9-rc3) and possible cause

[Thomas Gleixner <tglx@linutronix.de>]

On Sat, 2004-10-23 at 14:59 +0200, Javier Marcet wrote:
> I've been following quite closely the development of 2.6.9, testing
> every -rc release and a lot of -bk's.
> 
> Upon changing from 2.6.9-rc2 to 2.6.9-rc3 I began experiencing random
> oom kills whenever a high memory i/o load took place.
> This happened with plenty of free memory, and with whatever values I
> used for vm.overcommit_ratio and vm.overcommit_memory
> Doubling the physical RAM didn't change the situation either.
> 
> Having traced the problem to 2.6.9-rc3, I took a look at the differences
> in memory handling between 2.6.9-rc2 and 2.6.9-rc3 and with the attached
> patch I have no more oom kills. Not a single one.
> 
> I'm not saying everything within the patch is needed, not even that it's
> the right thing to change. Nonetheless, 2.6.9 vanilla was unusable,
> while this avoids those memory leaks.
> 
> Please, review and see what's wrong there :)

The changes in mempolicy.c are unrelated, except you have a NUMA enabled
machine.

The flush_dcache_page() is only relevant for non x86, as they result in
a NOP there.

tglx