diff options
author | Hugh Dickins <hughd@google.com> | 2012-01-13 01:19:56 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-13 04:13:10 (GMT) |
commit | 2bcf887963812c075f80a14e1fad8ec7e1c67acf (patch) | |
tree | 132f11eefe904653307a05b77d16f4c41866e486 | |
parent | 90b3feaec8ffb167abd8903bf111605c2f035aa8 (diff) | |
download | linux-2bcf887963812c075f80a14e1fad8ec7e1c67acf.tar.xz |
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>
-rw-r--r-- | include/linux/pagevec.h | 2 | ||||
-rw-r--r-- | mm/swap.c | 19 | ||||
-rw-r--r-- | mm/vmscan.c | 58 |
3 files changed, 40 insertions, 39 deletions
diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h index ed17024..9def912 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)) @@ -23,7 +23,6 @@ #include <linux/init.h> #include <linux/export.h> #include <linux/mm_inline.h> -#include <linux/buffer_head.h> /* for try_to_release_page() */ #include <linux/percpu_counter.h> #include <linux/percpu.h> #include <linux/cpu.h> @@ -730,24 +729,6 @@ void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru) EXPORT_SYMBOL(____pagevec_lru_add); -/* - * Try to drop buffers from the pages in a pagevec - */ -void pagevec_strip(struct pagevec *pvec) -{ - int i; - - for (i = 0; i < pagevec_count(pvec); i++) { - struct page *page = pvec->pages[i]; - - if (page_has_private(page) && trylock_page(page)) { - if (page_has_private(page)) - try_to_release_page(page, 0); - unlock_page(page); - } - } -} - /** * pagevec_lookup - gang pagecache lookup * @pvec: Where the resulting pages are placed diff --git a/mm/vmscan.c b/mm/vmscan.c index 25f9038..7724fb8 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1398,12 +1398,10 @@ putback_lru_pages(struct mem_cgroup_zone *mz, struct scan_control *sc, struct list_head *page_list) { struct page *page; - struct pagevec pvec; + LIST_HEAD(pages_to_free); struct zone *zone = mz->zone; struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz); - pagevec_init(&pvec, 1); - /* * Put back any unfreeable pages. */ @@ -1427,17 +1425,24 @@ putback_lru_pages(struct mem_cgroup_zone *mz, struct scan_control *sc, int numpages = hpage_nr_pages(page); reclaim_stat->recent_rotated[file] += numpages; } - if (!pagevec_add(&pvec, page)) { - spin_unlock_irq(&zone->lru_lock); - __pagevec_release(&pvec); - spin_lock_irq(&zone->lru_lock); + if (put_page_testzero(page)) { + __ClearPageLRU(page); + __ClearPageActive(page); + del_page_from_lru_list(zone, page, lru); + + if (unlikely(PageCompound(page))) { + spin_unlock_irq(&zone->lru_lock); + (*get_compound_page_dtor(page))(page); + spin_lock_irq(&zone->lru_lock); + } else + list_add(&page->lru, &pages_to_free); } } __mod_zone_page_state(zone, NR_ISOLATED_ANON, -nr_anon); __mod_zone_page_state(zone, NR_ISOLATED_FILE, -nr_file); spin_unlock_irq(&zone->lru_lock); - pagevec_release(&pvec); + free_hot_cold_page_list(&pages_to_free, 1); } static noinline_for_stack void @@ -1647,13 +1652,23 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz, static void move_active_pages_to_lru(struct zone *zone, struct list_head *list, + struct list_head *pages_to_free, enum lru_list lru) { unsigned long pgmoved = 0; - struct pagevec pvec; struct page *page; - pagevec_init(&pvec, 1); + if (buffer_heads_over_limit) { + spin_unlock_irq(&zone->lru_lock); + list_for_each_entry(page, list, lru) { + if (page_has_private(page) && trylock_page(page)) { + if (page_has_private(page)) + try_to_release_page(page, 0); + unlock_page(page); + } + } + spin_lock_irq(&zone->lru_lock); + } while (!list_empty(list)) { struct lruvec *lruvec; @@ -1667,12 +1682,17 @@ static void move_active_pages_to_lru(struct zone *zone, list_move(&page->lru, &lruvec->lists[lru]); pgmoved += hpage_nr_pages(page); - if (!pagevec_add(&pvec, page) || list_empty(list)) { - spin_unlock_irq(&zone->lru_lock); - if (buffer_heads_over_limit) - pagevec_strip(&pvec); - __pagevec_release(&pvec); - spin_lock_irq(&zone->lru_lock); + if (put_page_testzero(page)) { + __ClearPageLRU(page); + __ClearPageActive(page); + del_page_from_lru_list(zone, page, lru); + + if (unlikely(PageCompound(page))) { + spin_unlock_irq(&zone->lru_lock); + (*get_compound_page_dtor(page))(page); + spin_lock_irq(&zone->lru_lock); + } else + list_add(&page->lru, pages_to_free); } } __mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved); @@ -1766,12 +1786,14 @@ static void shrink_active_list(unsigned long nr_pages, */ reclaim_stat->recent_rotated[file] += nr_rotated; - move_active_pages_to_lru(zone, &l_active, + move_active_pages_to_lru(zone, &l_active, &l_hold, LRU_ACTIVE + file * LRU_FILE); - move_active_pages_to_lru(zone, &l_inactive, + move_active_pages_to_lru(zone, &l_inactive, &l_hold, LRU_BASE + file * LRU_FILE); __mod_zone_page_state(zone, NR_ISOLATED_ANON + file, -nr_taken); spin_unlock_irq(&zone->lru_lock); + + free_hot_cold_page_list(&l_hold, 1); } #ifdef CONFIG_SWAP |