diff options
| author | Hugh Dickins <[email protected]> | 2015-09-08 15:03:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2015-09-08 15:35:28 -0700 |
| commit | 7fadc820222497eac234d1d51a66517c00a6ca4c (patch) | |
| tree | a4e8a91b85b33fc9532c808dee54dda46f5f380c | |
| parent | 26f5d7609f03ad8d6dc552458e4e371a62416b37 (diff) | |
mm, vmscan: unlock page while waiting on writeback
This is merely a politeness: I've not found that shrink_page_list()
leads to deadlock with the page it holds locked across
wait_on_page_writeback(); but nevertheless, why hold others off by
keeping the page locked there?
And while we're at it: remove the mistaken "not " from the commentary on
this Case 3 (and a distracting blank line from Case 2, if I may).
Signed-off-by: Hugh Dickins <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Cc: Mel Gorman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | mm/vmscan.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 8276a3a615ca..2d978b28a410 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -985,7 +985,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, * __GFP_IO|__GFP_FS for this reason); but more thought * would probably show more reasons. * - * 3) Legacy memcg encounters a page that is not already marked + * 3) Legacy memcg encounters a page that is already marked * PageReclaim. memcg does not have any dirty pages * throttling so we could easily OOM just because too many * pages are in writeback and there is nothing else to @@ -1015,12 +1015,15 @@ static unsigned long shrink_page_list(struct list_head *page_list, */ SetPageReclaim(page); nr_writeback++; - goto keep_locked; /* Case 3 above */ } else { + unlock_page(page); wait_on_page_writeback(page); + /* then go back and try same page again */ + list_add_tail(&page->lru, page_list); + continue; } } |