Messages in this thread | | | Date | Wed, 01 Oct 2008 10:01:46 -0500 | From | Christoph Lameter <> | Subject | Re: [PATCH 4/4] capture pages freed during direct reclaim for allocation by the reclaimer |
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Andy Whitcroft wrote: > When a process enters direct reclaim it will expend effort identifying > and releasing pages in the hope of obtaining a page. However as these > pages are released asynchronously there is every possibility that the > pages will have been consumed by other allocators before the reclaimer > gets a look in. This is particularly problematic where the reclaimer is > attempting to allocate a higher order page. It is highly likely that > a parallel allocation will consume lower order constituent pages as we > release them preventing them coelescing into the higher order page the > reclaimer desires.
The reclaim problem is due to the pcp queueing right? Could we disable pcp queueing during reclaim? pcp processing is not necessarily a gain, so temporarily disabling it should not be a problem.
At the beginning of reclaim just flush all pcp pages and then do not allow pcp refills again until reclaim is finished?
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