path: root/fs
diff options
authorHugh Dickins <hugh.dickins@tiscali.co.uk>2009-09-21 17:02:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-22 07:17:31 -0700
commit9a840895147b12de5cdd633c600b38686840ee53 (patch)
treea266a69a39decb4ec0364ac331f0ab19b6f09f06 /fs
parent21333b2b66b805a360641568588e5a0bb06d9d1f (diff)
ksm: identify PageKsm pages
KSM will need to identify its kernel merged pages unambiguously, and /proc/kpageflags will probably like to do so too. Since KSM will only be substituting anonymous pages, statistics are best preserved by making a PageKsm page a special PageAnon page: one with no anon_vma. But KSM then needs its own page_add_ksm_rmap() - keep it in ksm.h near PageKsm; and do_wp_page() must COW them, unlike singly mapped PageAnons. 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: Wu Fengguang <fengguang.wu@intel.com> 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 'fs')
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/proc/page.c b/fs/proc/page.c
index 2707c6c7a20..2281c2cbfe2 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -2,6 +2,7 @@
#include <linux/compiler.h>
#include <linux/fs.h>
#include <linux/init.h>
+#include <linux/ksm.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/proc_fs.h>
@@ -95,6 +96,8 @@ static const struct file_operations proc_kpagecount_operations = {
#define KPF_NOPAGE 20
+#define KPF_KSM 21
/* kernel hacking assistances
* WARNING: subject to change, never rely on them!
@@ -137,6 +140,8 @@ static u64 get_uflags(struct page *page)
u |= 1 << KPF_MMAP;
if (PageAnon(page))
u |= 1 << KPF_ANON;
+ if (PageKsm(page))
+ u |= 1 << KPF_KSM;
* compound pages: export both head/tail info