Commit 4fad7fb6 authored by David Rientjes's avatar David Rientjes Committed by Linus Torvalds
Browse files

mm, thp: fix setting of defer+madvise thp defrag mode 

Setting thp defrag mode of "defer+madvise" actually sets "defer" in the
kernel due to the name similarity and the out-of-order way the string is
checked in defrag_store().

Check the string in the correct order so that
TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG is set appropriately for
"defer+madvise".

Fixes: 21440d7e ("mm, thp: add new defer+madvise defrag option")
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1704051814420.137626@chino.kir.corp.google.com


Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5402e97a

mm/huge_memory.c

+6 −6
Original line number Diff line number Diff line
@@ -240,18 +240,18 @@ static ssize_t defrag_store(struct kobject *kobj, 
		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags);

		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags);

		set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags);

	} else if (!memcmp("defer", buf,

		    min(sizeof("defer")-1, count))) {

		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags);

		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags);

		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags);

		set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags);

	} else if (!memcmp("defer+madvise", buf,

		    min(sizeof("defer+madvise")-1, count))) {

		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags);

		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags);

		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags);

		set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags);

	} else if (!memcmp("defer", buf,

		    min(sizeof("defer")-1, count))) {

		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags);

		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags);

		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags);

		set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags);

	} else if (!memcmp("madvise", buf,

			   min(sizeof("madvise")-1, count))) {

		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags);

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