Messages in this thread | | | Date | Tue, 17 Oct 2017 14:03:18 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH 1/2] mm: drop migrate type checks from has_unmovable_pages |
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On Tue 17-10-17 22:41:08, Michael Ellerman wrote: > Michal Hocko <mhocko@kernel.org> writes: > > > From: Michal Hocko <mhocko@suse.com> > > > > Michael has noticed that the memory offline tries to migrate kernel code > > pages when doing > > echo 0 > /sys/devices/system/memory/memory0/online > > > > The current implementation will fail the operation after several failed > > page migration attempts but we shouldn't even attempt to migrate > > that memory and fail right away because this memory is clearly not > > migrateable. This will become a real problem when we drop the retry loop > > counter resp. timeout. > > > > The real problem is in has_unmovable_pages in fact. We should fail if > > there are any non migrateable pages in the area. In orther to guarantee > > that remove the migrate type checks because MIGRATE_MOVABLE is not > > guaranteed to contain only migrateable pages. It is merely a heuristic. > > Similarly MIGRATE_CMA does guarantee that the page allocator doesn't > > allocate any non-migrateable pages from the block but CMA allocations > > themselves are unlikely to migrateable. Therefore remove both checks. > > > > Reported-by: Michael Ellerman <mpe@ellerman.id.au> > > Signed-off-by: Michal Hocko <mhocko@suse.com> > > Thanks, that works for me. > > Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Thanks a lot Michael!
Andrew, could you add these two patches and merge them before mm-memory_hotplug-do-not-fail-offlining-too-early.patch? Or should I rather repost the full series (including 2 already merged patches? again? -- Michal Hocko SUSE Labs
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