Re: [PATCH 0/5] Candidate fix for increased number of GFP_ATOMICfailures V2

[Tobias Diedrich]

Mel Gorman wrote:
> On Fri, Nov 06, 2009 at 07:03:23AM +0100, Tobias Diedrich wrote:
> > Mel Gorman wrote:
> > > [No BZ ID] Kernel crash on 2.6.31.x (kcryptd: page allocation failure..)
> > > 	This apparently is easily reproducible, particular in comparison to
> > > 	the other reports. The point of greatest interest is that this is
> > > 	order-0 GFP_ATOMIC failures. Sven, I'm hoping that you in particular
> > > 	will be able to follow the tests below as you are the most likely
> > > 	person to have an easily reproducible situation.
> > 
> > I've also seen order-0 failures on 2.6.31.5:
> > Note that this is with a one process hogging and mlocking memory and
> > min_free_kbytes reduced to 100 to reproduce the problem more easily.
> > 
> 
> Is that a vanilla, with patches 1-3 applied or both?
That was on vanilla 2.6.31.5.

I tried 2.6.31.5 before with patches 1+2 and netconsole enabled and
still got the order-1 failures (apparently I get order-1 failures
with netconsole and order-0 failures without).

> > I tried bisecting the issue, but in the end without memory pressure
> > I can't reproduce it reliably and with the above mentioned pressure
> > I get allocation failures even on 2.6.30.o
> 
> To be honest, it's not entirely unexpected with min_free_kbytes set that
> low. The system should cope with a certain amount of pressure but with
> pressure and a low min_free_kbytes, the system will simply be reacting
> too late to free memory in the non-atomic paths.
Maybe I should try again on 2.6.30 without netconsole und try
increasing min_free_kbytes until the allocation failures
disappear and try to bisect again with that setting...

-- 
Tobias						PGP: http://8ef7ddba.uguu.de
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