diff options
author | Hugh Dickins <hugh@veritas.com> | 2009-01-06 17:39:34 -0500 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-06 18:59:03 -0500 |
commit | 7b1fe59793e61f826bef053107b57b23954833bb (patch) | |
tree | 0ac769c48123c5d0770b0a0f88bad9e6318b83ed /mm/memory.c | |
parent | ab967d86015a19777955370deebc8262d50fed63 (diff) |
mm: reuse_swap_page replaces can_share_swap_page
A good place to free up old swap is where do_wp_page(), or do_swap_page(),
is about to redirty the page: the data on disk is then stale and won't be
read again; and if we do decide to write the page out later, using the
previous swap location makes an unnecessary disk seek very likely.
So give can_share_swap_page() the side-effect of delete_from_swap_cache()
when it safely can. And can_share_swap_page() was always a misleading
name, the more so if it has a side-effect: rename it reuse_swap_page().
Irrelevant cleanup nearby: remove swap_token_default_timeout definition
from swap.h: it's used nowhere.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Robin Holt <holt@sgi.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 | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c index 3922ffcf3dff..8f471edcb985 100644 --- a/mm/memory.c +++ b/mm/memory.c | |||
@@ -1861,7 +1861,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, | |||
1861 | } | 1861 | } |
1862 | page_cache_release(old_page); | 1862 | page_cache_release(old_page); |
1863 | } | 1863 | } |
1864 | reuse = can_share_swap_page(old_page); | 1864 | reuse = reuse_swap_page(old_page); |
1865 | unlock_page(old_page); | 1865 | unlock_page(old_page); |
1866 | } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) == | 1866 | } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) == |
1867 | (VM_WRITE|VM_SHARED))) { | 1867 | (VM_WRITE|VM_SHARED))) { |
@@ -2392,7 +2392,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, | |||
2392 | 2392 | ||
2393 | inc_mm_counter(mm, anon_rss); | 2393 | inc_mm_counter(mm, anon_rss); |
2394 | pte = mk_pte(page, vma->vm_page_prot); | 2394 | pte = mk_pte(page, vma->vm_page_prot); |
2395 | if (write_access && can_share_swap_page(page)) { | 2395 | if (write_access && reuse_swap_page(page)) { |
2396 | pte = maybe_mkwrite(pte_mkdirty(pte), vma); | 2396 | pte = maybe_mkwrite(pte_mkdirty(pte), vma); |
2397 | write_access = 0; | 2397 | write_access = 0; |
2398 | } | 2398 | } |