Commit b06eda09 authored Apr 01, 2020 by Rik van Riel Committed by Linus Torvalds Apr 02, 2020

mm,compaction,cma: add alloc_contig flag to compact_control



Patch series "fix THP migration for CMA allocations", v2.

Transparent huge pages are allocated with __GFP_MOVABLE, and can end up in
CMA memory blocks.  Transparent huge pages also have most of the
infrastructure in place to allow migration.

However, a few pieces were missing, causing THP migration to fail when
attempting to use CMA to allocate 1GB hugepages.

With these patches in place, THP migration from CMA blocks seems to work,
both for anonymous THPs and for tmpfs/shmem THPs.

This patch (of 2):

Add information to struct compact_control to indicate that the allocator
would really like to clear out this specific part of memory, used by for
example CMA.

Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Link: http://lkml.kernel.org/r/20200227213238.1298752-1-riel@surriel.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent eea274d6

mm/internal.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -229,6 +229,7 @@ struct compact_control {
		bool whole_zone; /* Whole zone should/has been scanned */
		bool contended; /* Signal lock or sched contention */
		bool rescan; /* Rescanning the same pageblock */
		bool alloc_contig; /* alloc_contig_range allocation */
		};

		/*

mm/page_alloc.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -8400,6 +8400,7 @@ int alloc_contig_range(unsigned long start, unsigned long end,
		.ignore_skip_hint = true,
		.no_set_skip_hint = true,
		.gfp_mask = current_gfp_context(gfp_mask),
		.alloc_contig = true,
		};
		INIT_LIST_HEAD(&cc.migratepages);

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