mm: defer flush of writable TLB entries
authorMel Gorman <mgorman@suse.de>
Fri, 4 Sep 2015 22:47:35 +0000 (15:47 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 4 Sep 2015 23:54:41 +0000 (16:54 -0700)
commitd950c9477d51f0cefc2ed3cf76e695d46af0d9c1
treed6ba89db328ec09b2140a84dcdf1bd8ca5cbeaa4
parent72b252aed506b8f1a03f7abd29caef4cdf6a043b
mm: defer flush of writable TLB entries

If a PTE is unmapped and it's dirty then it was writable recently.  Due to
deferred TLB flushing, it's best to assume a writable TLB cache entry
exists.  With that assumption, the TLB must be flushed before any IO can
start or the page is freed to avoid lost writes or data corruption.  This
patch defers flushing of potentially writable TLBs as long as possible.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/sched.h
mm/internal.h
mm/rmap.c
mm/vmscan.c