diff options
| author | Mel Gorman <mgorman@suse.de> | 2011-04-25 21:36:42 +0000 |
|---|---|---|
| committer | Marek Szyprowski <m.szyprowski@samsung.com> | 2012-05-21 15:09:34 +0200 |
| commit | cfd3da1e49bb95c355c01c0f502d657deb3d34a4 (patch) | |
| tree | 002aa5a9001a7b600ea8af90b59ccbbe133d48e0 /mm/page_alloc.c | |
| parent | 0815f3d81d76dfbf2abcfd93a85ff0a6008fe4c0 (diff) | |
mm: Serialize access to min_free_kbytes
There is a race between the min_free_kbytes sysctl, memory hotplug
and transparent hugepage support enablement. Memory hotplug uses a
zonelists_mutex to avoid a race when building zonelists. Reuse it to
serialise watermark updates.
[a.p.zijlstra@chello.nl: Older patch fixed the race with spinlock]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Barry Song <Baohua.Song@csr.com>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 116c087f76b..8be37bcda0b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5020,14 +5020,7 @@ static void setup_per_zone_lowmem_reserve(void) calculate_totalreserve_pages(); } -/** - * setup_per_zone_wmarks - called when min_free_kbytes changes - * or when memory is hot-{added|removed} - * - * Ensures that the watermark[min,low,high] values for each zone are set - * correctly with respect to min_free_kbytes. - */ -void setup_per_zone_wmarks(void) +static void __setup_per_zone_wmarks(void) { unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); unsigned long lowmem_pages = 0; @@ -5082,6 +5075,20 @@ void setup_per_zone_wmarks(void) calculate_totalreserve_pages(); } +/** + * setup_per_zone_wmarks - called when min_free_kbytes changes + * or when memory is hot-{added|removed} + * + * Ensures that the watermark[min,low,high] values for each zone are set + * correctly with respect to min_free_kbytes. + */ +void setup_per_zone_wmarks(void) +{ + mutex_lock(&zonelists_mutex); + __setup_per_zone_wmarks(); + mutex_unlock(&zonelists_mutex); +} + /* * The inactive anon list should be small enough that the VM never has to * do too much work, but large enough that each inactive page has a chance |