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authorVlastimil Babka <vbabka@suse.cz>2017-11-18 00:26:34 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-18 01:10:00 +0100
commitb527cfe5bc23208cf9a346879501333cec638aba (patch)
tree3302cb8445a9ae8edd1ac187ffef8dc8f84f9781 /lib/decompress_inflate.c
parentmm, compaction: persistently skip hugetlbfs pageblocks (diff)
downloadlinux-b527cfe5bc23208cf9a346879501333cec638aba.tar.xz
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mm, compaction: extend pageblock_skip_persistent() to all compound pages
pageblock_skip_persistent() checks for HugeTLB pages of pageblock order. When clearing pageblock skip bits for compaction, the bits are not cleared for such pageblocks, because they cannot contain base pages suitable for migration, nor free pages to use as migration targets. This optimization can be simply extended to all compound pages of order equal or larger than pageblock order, because migrating such pages (if they support it) cannot help sub-pageblock fragmentation. This includes THP's and also gigantic HugeTLB pages, which the current implementation doesn't persistently skip due to a strict pageblock_order equality check and not recognizing tail pages. While THP pages are generally less "persistent" than HugeTLB, we can still expect that if a THP exists at the point of __reset_isolation_suitable(), it will exist also during the subsequent compaction run. The time difference here could be actually smaller than between a compaction run that sets a (non-persistent) skip bit on a THP, and the next compaction run that observes it. Link: http://lkml.kernel.org/r/20171102121706.21504-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/decompress_inflate.c')
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