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| author | Jens Axboe <jaxboe@fusionio.com> | 2010-10-19 09:13:04 +0200 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2010-10-19 09:13:04 +0200 |
| commit | fa251f89903d73989e2f63e13d0eaed1e07ce0da (patch) | |
| tree | 3f7fe779941e3b6d67754dd7c44a32f48ea47c74 /mm/mmzone.c | |
| parent | dd3932eddf428571762596e17b65f5dc92ca361b (diff) | |
| parent | cd07202cc8262e1669edff0d97715f3dd9260917 (diff) | |
| download | op-kernel-dev-fa251f89903d73989e2f63e13d0eaed1e07ce0da.zip op-kernel-dev-fa251f89903d73989e2f63e13d0eaed1e07ce0da.tar.gz | |
Merge branch 'v2.6.36-rc8' into for-2.6.37/barrier
Conflicts:
block/blk-core.c
drivers/block/loop.c
mm/swapfile.c
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'mm/mmzone.c')
| -rw-r--r-- | mm/mmzone.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/mm/mmzone.c b/mm/mmzone.c index f5b7d17..e35bfb8 100644 --- a/mm/mmzone.c +++ b/mm/mmzone.c @@ -87,3 +87,24 @@ int memmap_valid_within(unsigned long pfn, return 1; } #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */ + +#ifdef CONFIG_SMP +/* Called when a more accurate view of NR_FREE_PAGES is needed */ +unsigned long zone_nr_free_pages(struct zone *zone) +{ + unsigned long nr_free_pages = zone_page_state(zone, NR_FREE_PAGES); + + /* + * While kswapd is awake, it is considered the zone is under some + * memory pressure. Under pressure, there is a risk that + * per-cpu-counter-drift will allow the min watermark to be breached + * potentially causing a live-lock. While kswapd is awake and + * free pages are low, get a better estimate for free pages + */ + if (nr_free_pages < zone->percpu_drift_mark && + !waitqueue_active(&zone->zone_pgdat->kswapd_wait)) + return zone_page_state_snapshot(zone, NR_FREE_PAGES); + + return nr_free_pages; +} +#endif /* CONFIG_SMP */ |
