Messages in this thread | | | Date | Wed, 25 Nov 2015 12:57:08 -0800 (PST) | From | David Rientjes <> | Subject | Re: [PATCH 1/2] mm, oom: Give __GFP_NOFAIL allocations access to memory reserves |
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On Wed, 25 Nov 2015, Michal Hocko wrote:
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 8034909faad2..94b04c1e894a 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -2766,8 +2766,13 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, > goto out; > } > /* Exhausted what can be done so it's blamo time */ > - if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) > + if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) { > *did_some_progress = 1; > + > + if (gfp_mask & __GFP_NOFAIL) > + page = get_page_from_freelist(gfp_mask, order, > + ALLOC_NO_WATERMARKS, ac); > + } > out: > mutex_unlock(&oom_lock); > return page;
Well, sure, that's one way to do it, but for cpuset users, wouldn't this lead to a depletion of the first system zone since you've dropped ALLOC_CPUSET and are doing ALLOC_NO_WATERMARKS in the same call? get_page_from_freelist() shouldn't be doing any balancing over the set of allowed zones. Can you justify depleting memory reserves on a zone outside of the set of allowed cpuset mems rather than trying to drop ALLOC_CPUSET first?
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