The patch titled
vmscan: let GFP_NOFS go to swap again
has been added to the -mm tree. Its filename is
vmscan-let-gfp_nofs-go-to-swap-again.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: vmscan: let GFP_NOFS go to swap again
From: Hugh Dickins <hugh@xxxxxxxxxxx>
In the past, GFP_NOFS (but of course not GFP_NOIO) was allowed to reclaim
by writing to swap. That got partially broken in 2.6.23, when may_enter_fs
initialization was moved up before the allocation of swap, so its
PageSwapCache test was failing the first time around,
Fix it by setting may_enter_fs when add_to_swap() succeeds with
__GFP_IO. In fact, check __GFP_IO before calling add_to_swap():
allocating swap we're not ready to use just increases disk seeking.
Signed-off-by: Hugh Dickins <hugh@xxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 3 +++
1 file changed, 3 insertions(+)
diff -puN mm/vmscan.c~vmscan-let-gfp_nofs-go-to-swap-again mm/vmscan.c
--- a/mm/vmscan.c~vmscan-let-gfp_nofs-go-to-swap-again
+++ a/mm/vmscan.c
@@ -672,6 +672,8 @@ static unsigned long shrink_page_list(st
* Try to allocate it some swap space here.
*/
if (PageAnon(page) && !PageSwapCache(page)) {
+ if (!(sc->gfp_mask & __GFP_IO))
+ goto keep_locked;
switch (try_to_munlock(page)) {
case SWAP_FAIL: /* shouldn't happen */
case SWAP_AGAIN:
@@ -683,6 +685,7 @@ static unsigned long shrink_page_list(st
}
if (!add_to_swap(page, GFP_ATOMIC))
goto activate_locked;
+ may_enter_fs = 1;
}
#endif /* CONFIG_SWAP */
_
Patches currently in -mm which might be from hugh@xxxxxxxxxxx are
origin.patch
linux-next.patch
sprint_symbol-use-less-stack.patch
migration-fix-writepage-error.patch
vmscan-let-gfp_nofs-go-to-swap-again.patch
dont-unlink-an-active-swapfile.patch
mm-implement-remap_pfn_range-with-apply_to_page_range.patch
mm-apply_to_range-call-pte-function-with-lazy-updates.patch
mm-remap_pfn_range-restore-missing-flush.patch
prio_tree-debugging-patch.patch
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