Messages in this thread | | | Date | Mon, 25 Jun 2012 16:33:29 -0700 | Subject | Re: [PATCH 02/11] memcg: Reclaim when more than one page needed. | From | Suleiman Souhlal <> |
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On Mon, Jun 25, 2012 at 7:15 AM, Glauber Costa <glommer@parallels.com> wrote: > From: Suleiman Souhlal <ssouhlal@FreeBSD.org> > > mem_cgroup_do_charge() was written before slab accounting, and expects > three cases: being called for 1 page, being called for a stock of 32 pages, > or being called for a hugepage. If we call for 2 or 3 pages (and several > slabs used in process creation are such, at least with the debug options I > had), it assumed it's being called for stock and just retried without reclaiming. > > Fix that by passing down a minsize argument in addition to the csize. > > And what to do about that (csize == PAGE_SIZE && ret) retry? If it's > needed at all (and presumably is since it's there, perhaps to handle > races), then it should be extended to more than PAGE_SIZE, yet how far? > And should there be a retry count limit, of what? For now retry up to > COSTLY_ORDER (as page_alloc.c does), stay safe with a cond_resched(), > and make sure not to do it if __GFP_NORETRY.
The commit description mentions COSTLY_ORDER, but it's not actually used in the patch.
-- Suleiman
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