From: Hugh Dickins <hugh.dickins@tiscali.co.uk>
To: Andrew Morton <akpm@linux-foundation.com>
Cc: Andi Kleen <andi@firstfloor.org>,
Wu Fengguang <fengguang.wu@intel.com>,
Izik Eidus <ieidus@redhat.com>, Chris Wright <chrisw@redhat.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Michael Kerrisk <mtk.manpages@gmail.com>,
Richard Henderson <rth@twiddle.net>,
Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
Ralf Baechle <ralf@linux-mips.org>,
Kyle McMartin <kyle@mcmartin.ca>, Helge Deller <deller@gmx.de>,
Chris Zankel <chris@zankel.net>, Rik van RIel <riel@redhat.com>,
Balbir Singh <balbir@in.ibm.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Avi Kivity <avi@redhat.com>,
Nick Piggin <nickpiggin@yahoo.com.au>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: [PATCH mmotm] ksm: antidote to MADV_MERGEABLE HWPOISON
Date: Fri, 21 Aug 2009 19:30:15 +0100 (BST) [thread overview]
Message-ID: <Pine.LNX.4.64.0908211912330.14259@sister.anvils> (raw)
linux-next is now sporting MADV_HWPOISON at 12, which would have a very
nasty effect on KSM if you had CONFIG_MEMORY_FAILURE=y with CONFIG_KSM=y.
Shift MADV_MERGEABLE and MADV_UNMERGEABLE down two - two to reduce the
confusion if old and new userspace and kernel are mismatched.
Personally I'd prefer the MADV_HWPOISON testing feature to shift; but
linux-next comes first in the mmotm lineup, and I can't be sure that
madvise KSM already has more users than there are HWPOISON testers:
so unless Andi is happy to shift MADV_HWPOISON, mmotm needs this.
---
Fix to ksm-define-madv_mergeable-and-madv_unmergeable.patch
parisc unaffected because its MADVs are displaced.
arch/alpha/include/asm/mman.h | 4 ++--
arch/mips/include/asm/mman.h | 4 ++--
arch/xtensa/include/asm/mman.h | 4 ++--
include/asm-generic/mman-common.h | 4 ++--
4 files changed, 8 insertions(+), 8 deletions(-)
--- mmotm/arch/alpha/include/asm/mman.h 2009-08-21 12:08:18.000000000 +0100
+++ linux/arch/alpha/include/asm/mman.h 2009-08-21 18:28:14.000000000 +0100
@@ -48,8 +48,8 @@
#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 */
+#define MADV_MERGEABLE 14 /* KSM may merge identical pages */
+#define MADV_UNMERGEABLE 15 /* KSM may not merge identical pages */
/* compatibility flags */
#define MAP_FILE 0
--- mmotm/arch/mips/include/asm/mman.h 2009-08-21 12:08:18.000000000 +0100
+++ linux/arch/mips/include/asm/mman.h 2009-08-21 18:28:24.000000000 +0100
@@ -71,8 +71,8 @@
#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 */
+#define MADV_MERGEABLE 14 /* KSM may merge identical pages */
+#define MADV_UNMERGEABLE 15 /* KSM may not merge identical pages */
/* compatibility flags */
#define MAP_FILE 0
--- mmotm/arch/xtensa/include/asm/mman.h 2009-08-21 12:08:18.000000000 +0100
+++ linux/arch/xtensa/include/asm/mman.h 2009-08-21 18:28:52.000000000 +0100
@@ -78,8 +78,8 @@
#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 */
+#define MADV_MERGEABLE 14 /* KSM may merge identical pages */
+#define MADV_UNMERGEABLE 15 /* KSM may not merge identical pages */
/* compatibility flags */
#define MAP_FILE 0
--- mmotm/include/asm-generic/mman-common.h 2009-08-21 12:08:18.000000000 +0100
+++ linux/include/asm-generic/mman-common.h 2009-08-21 18:29:01.000000000 +0100
@@ -36,8 +36,8 @@
#define MADV_DOFORK 11 /* do inherit across fork */
#define MADV_HWPOISON 12 /* poison a page for testing */
-#define MADV_MERGEABLE 12 /* KSM may merge identical pages */
-#define MADV_UNMERGEABLE 13 /* KSM may not merge identical pages */
+#define MADV_MERGEABLE 14 /* KSM may merge identical pages */
+#define MADV_UNMERGEABLE 15 /* KSM may not merge identical pages */
/* compatibility flags */
#define MAP_FILE 0
--
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next reply other threads:[~2009-08-21 18:30 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-21 18:30 Hugh Dickins [this message]
2009-08-21 18:41 ` Andi Kleen
2009-08-21 19:23 ` Hugh Dickins
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