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author | Hugh Dickins <hugh.dickins@tiscali.co.uk> | 2009-09-22 02:01:59 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-22 16:17:31 +0200 |
commit | 21333b2b66b805a360641568588e5a0bb06d9d1f (patch) | |
tree | c0ce4d31e31ae2d2b1ef975b00c0611a3099c7a3 /mm/memory.c | |
parent | ksm: the mm interface to ksm (diff) | |
download | linux-21333b2b66b805a360641568588e5a0bb06d9d1f.tar.xz linux-21333b2b66b805a360641568588e5a0bb06d9d1f.zip |
ksm: no debug in page_dup_rmap()
page_dup_rmap(), used on each mapped page when forking, was originally
just an inline atomic_inc of mapcount. 2.6.22 added CONFIG_DEBUG_VM
out-of-line checks to it, which would need to be ever-so-slightly
complicated to allow for the PageKsm() we're about to define.
But I think these checks never caught anything. And if it's coding errors
we're worried about, such checks should be in page_remove_rmap() too, not
just when forking; whereas if it's pagetable corruption we're worried
about, then they shouldn't be limited to CONFIG_DEBUG_VM.
Oh, just revert page_dup_rmap() to an inline atomic_inc of mapcount.
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: Nick Piggin <npiggin@suse.de>
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
-rw-r--r-- | mm/memory.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/memory.c b/mm/memory.c index 368561f32009..7a61a11f1867 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -597,7 +597,7 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, page = vm_normal_page(vma, addr, pte); if (page) { get_page(page); - page_dup_rmap(page, vma, addr); + page_dup_rmap(page); rss[!!PageAnon(page)]++; } |