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| author | Hugh Dickins <hughd@google.com> | 2012-01-12 17:19:56 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-12 20:13:10 -0800 |
| commit | 2bcf887963812c075f80a14e1fad8ec7e1c67acf (patch) | |
| tree | 132f11eefe904653307a05b77d16f4c41866e486 /include/linux/pagevec.h | |
| parent | 90b3feaec8ffb167abd8903bf111605c2f035aa8 (diff) | |
| download | lwn-2bcf887963812c075f80a14e1fad8ec7e1c67acf.tar.gz lwn-2bcf887963812c075f80a14e1fad8ec7e1c67acf.zip | |
mm: take pagevecs off reclaim stack
Replace pagevecs in putback_lru_pages() and move_active_pages_to_lru()
by lists of pages_to_free: then apply Konstantin Khlebnikov's
free_hot_cold_page_list() to them instead of pagevec_release().
Which simplifies the flow (no need to drop and retake lock whenever
pagevec fills up) and reduces stale addresses in stack backtraces
(which often showed through the pagevecs); but more importantly,
removes another 120 bytes from the deepest stacks in page reclaim.
Although I've not recently seen an actual stack overflow here with
a vanilla kernel, move_active_pages_to_lru() has often featured in
deep backtraces.
However, free_hot_cold_page_list() does not handle compound pages
(nor need it: a Transparent HugePage would have been split by the
time it reaches the call in shrink_page_list()), but it is possible
for putback_lru_pages() or move_active_pages_to_lru() to be left
holding the last reference on a THP, so must exclude the unlikely
compound case before putting on pages_to_free.
Remove pagevec_strip(), its work now done in move_active_pages_to_lru().
The pagevec in scan_mapping_unevictable_pages() remains in mm/vmscan.c,
but that is never on the reclaim path, and cannot be replaced by a list.
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/pagevec.h')
| -rw-r--r-- | include/linux/pagevec.h | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h index ed17024d2ebe..9def9121f8a2 100644 --- a/include/linux/pagevec.h +++ b/include/linux/pagevec.h @@ -22,7 +22,6 @@ struct pagevec { void __pagevec_release(struct pagevec *pvec); void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru); -void pagevec_strip(struct pagevec *pvec); unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping, pgoff_t start, unsigned nr_pages); unsigned pagevec_lookup_tag(struct pagevec *pvec, @@ -59,7 +58,6 @@ static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page) return pagevec_space(pvec); } - static inline void pagevec_release(struct pagevec *pvec) { if (pagevec_count(pvec)) |