Re: [Bug #14141] order 2 page allocation failures (generic)

Tobias Oetiker
2009-10-22T10:27:33Z

Hi Mel,

Tuesday Mel Gorman wrote:
> 4. Does the following patch help by any chance?
>
> Thanks
>
> ==== CUT HERE ====
> vmscan: Force kswapd to take notice faster when high-order watermarks are being hit
>
> When a high-order allocation fails, kswapd is kicked so that it reclaims
> at a higher-order to avoid direct reclaimers stall and to help GFP_ATOMIC
> allocations. Something has changed in recent kernels that affect the timing
> where high-order GFP_ATOMIC allocations are now failing with more frequency,
> particularly under pressure. This patch forces kswapd to notice sooner that
> high-order allocations are occuring by checking when watermarks are hit early
> and by having kswapd restart quickly when the reclaim order is increased.
>
> Not-signed-off-by-because-this-is-a-hatchet-job: Mel Gorman <mel@csn.ul.ie>
> ---

it does seem to help ... I have been running it from 6am to 12am on
our server now and have not yet seen any issues ...

will shout if I do ...

cheers
tobi

--
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
http://it.oetiker.ch tobi@oetiker.ch ++41 62 775 9902 / sb: -9900