Messages in this thread Patch in this message | | | Date | Tue, 17 Jan 2017 21:07:49 +0000 | From | Mel Gorman <> | Subject | Re: [PATCH 1/4] mm, page_alloc: Split buffered_rmqueue |
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On Tue, Jan 17, 2017 at 08:20:08PM +0000, Mel Gorman wrote: > It's late so I'm fairly tired but assuming I can reproduce this in the > morning, the first thing I'll try is something like this to force a reread > of mems_allowed; > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index ebea51cc0135..3fc2b3a8d301 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -3774,13 +3774,6 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, > .migratetype = gfpflags_to_migratetype(gfp_mask), > }; > > - if (cpusets_enabled()) { > - alloc_mask |= __GFP_HARDWALL; > - alloc_flags |= ALLOC_CPUSET; > - if (!ac.nodemask) > - ac.nodemask = &cpuset_current_mems_allowed; > - } > - > gfp_mask &= gfp_allowed_mask; > > lockdep_trace_alloc(gfp_mask); > @@ -3802,6 +3795,13 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, > alloc_flags |= ALLOC_CMA; > > retry_cpuset: > + if (cpusets_enabled()) { > + alloc_mask |= __GFP_HARDWALL; > + alloc_flags |= ALLOC_CPUSET; > + if (!nodemask) > + ac.nodemask = &cpuset_current_mems_allowed; > + } > + > cpuset_mems_cookie = read_mems_allowed_begin(); > > /* Dirty zone balancing only done in the fast path */ >
I later recalled that we looked at this before and didn't think a reinit was necessary because the location of cpuset_current_mems_allowed doesn't change so I came back and took another look. The location doesn't change but after the first attempt, we reset ac.nodemask to the given nodemask and don't recheck current_mems_allowed if the cpuset changed. The application of memory policies versus cpusets is a mess so it'll take time to pick apart to see if this is even remotely in the right direction.
-- Mel Gorman SUSE Labs
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