[PATCHv23 10/16] mm: Serialize access to min_free_kbytes
From: m.szyprowski@samsung.com (Marek Szyprowski)
Date: 2012-02-22 16:51:39
Also in:
linux-media, linux-mm, lkml
Subsystem:
memory management, memory management - page allocator, the rest · Maintainers:
Andrew Morton, Vlastimil Babka, Linus Torvalds
From: Mel Gorman <mgorman@suse.de> 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 at 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 <redacted> --- 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 e590b95..0aa8079 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c@@ -5027,14 +5027,7 @@ 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 pages_low = extra_free_kbytes >> (PAGE_SHIFT - 10);
@@ -5095,6 +5088,20 @@ 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
--
1.7.1.569.g6f426