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| author | David Rientjes <rientjes@google.com> | 2007-10-17 08:26:01 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-17 17:42:46 +0200 |
| commit | d773ed6b856a96bd6d18b6e04455e3ced0876da4 (patch) | |
| tree | f0235be6843ec323aeedcdadbee34a777b6c2690 /include | |
| parent | oom: convert zone_scan_lock from mutex to spinlock (diff) | |
| download | linux-d773ed6b856a96bd6d18b6e04455e3ced0876da4.tar.xz linux-d773ed6b856a96bd6d18b6e04455e3ced0876da4.zip | |
mm: test and set zone reclaim lock before starting reclaim
Introduces new zone flag interface for testing and setting flags:
int zone_test_and_set_flag(struct zone *zone, zone_flags_t flag)
Instead of setting and clearing ZONE_RECLAIM_LOCKED each time shrink_zone() is
called, this flag is test and set before starting zone reclaim. Zone reclaim
starts in __alloc_pages() when a zone's watermark fails and the system is in
zone_reclaim_mode. If it's already in reclaim, there's no need to start again
so it is simply considered full for that allocation attempt.
There is a change of behavior with regard to concurrent zone shrinking. It is
now possible for try_to_free_pages() or kswapd to already be shrinking a
particular zone when __alloc_pages() starts zone reclaim. In this case, it is
possible for two concurrent threads to invoke shrink_zone() for a single zone.
This change forbids a zone to be in zone reclaim twice, which was always the
behavior, but allows for concurrent try_to_free_pages() or kswapd shrinking
when starting zone reclaim.
Cc: Andrea Arcangeli <andrea@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/mmzone.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 9011505e740d..4c4522a51a3b 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -351,6 +351,12 @@ static inline void zone_set_flag(struct zone *zone, zone_flags_t flag) { set_bit(flag, &zone->flags); } + +static inline int zone_test_and_set_flag(struct zone *zone, zone_flags_t flag) +{ + return test_and_set_bit(flag, &zone->flags); +} + static inline void zone_clear_flag(struct zone *zone, zone_flags_t flag) { clear_bit(flag, &zone->flags); @@ -360,10 +366,12 @@ static inline int zone_is_all_unreclaimable(const struct zone *zone) { return test_bit(ZONE_ALL_UNRECLAIMABLE, &zone->flags); } + static inline int zone_is_reclaim_locked(const struct zone *zone) { return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags); } + static inline int zone_is_oom_locked(const struct zone *zone) { return test_bit(ZONE_OOM_LOCKED, &zone->flags); |