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authorHugh Dickins <hugh.dickins@tiscali.co.uk>2009-09-21 17:01:53 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-22 07:17:31 -0700
commitd19f352484467a5e518639ddff0554669c10ffab (patch)
tree87c31fff63fd3dccb2e47ddfee878a11228b7777 /include/asm-generic
parent3866ea90d3635ddddcd77ce51087222ac7de85f2 (diff)
ksm: define MADV_MERGEABLE and MADV_UNMERGEABLE
The out-of-tree KSM used ioctls on fds cloned from /dev/ksm to register a memory area for merging: we prefer now to use an madvise(2) interface. This patch just defines MADV_MERGEABLE (to tell KSM it may merge pages in this area found identical to pages in other mergeable areas) and MADV_UNMERGEABLE (to undo that). Most architectures use asm-generic, but alpha, mips, parisc, xtensa need their own definitions: included here for mmotm convenience, but we'll probably want to split this and feed pieces to arch maintainers. Based upon earlier patches by Chris Wright and Izik Eidus. Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by: Chris Wright <chrisw@redhat.com> Signed-off-by: Izik Eidus <ieidus@redhat.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Helge Deller <deller@gmx.de> Cc: Chris Zankel <chris@zankel.net> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Avi Kivity <avi@redhat.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/mman-common.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/include/asm-generic/mman-common.h b/include/asm-generic/mman-common.h
index 3b69ad34189..dd63bd38864 100644
--- a/include/asm-generic/mman-common.h
+++ b/include/asm-generic/mman-common.h
@@ -35,6 +35,9 @@
#define MADV_DONTFORK 10 /* don't inherit across fork */
#define MADV_DOFORK 11 /* do inherit across fork */
+#define MADV_MERGEABLE 12 /* KSM may merge identical pages */
+#define MADV_UNMERGEABLE 13 /* KSM may not merge identical pages */
+
/* compatibility flags */
#define MAP_FILE 0