[PATCH -mmotm 01/30] mm: serialize access to min_free_kbytes
in [Kernel]
|
Prev: [PATCH -mmotm 03/30] mm: expose gfp_to_alloc_flags()
Next: [PATCH -mmotm 09/30] mm: system wide ALLOC_NO_WATERMARK
From: Xiaotian Feng on 13 Jul 2010 06:20 From bc55bacd6bcc0f8a69c0d7e0d554c78237233e07 Mon Sep 17 00:00:00 2001 From: Xiaotian Feng <dfeng(a)redhat.com> Date: Mon, 12 Jul 2010 17:58:34 +0800 Subject: [PATCH 01/30] mm: serialize access to min_free_kbytes There is a small race between the procfs caller and the memory hotplug caller of setup_per_zone_wmarks(). Not a big deal, but the next patch will add yet another caller. Time to close the gap. Signed-off-by: Peter Zijlstra <a.p.zijlstra(a)chello.nl> Signed-off-by: Suresh Jayaraman <sjayaraman(a)suse.de> Signed-off-by: Xiaotian Feng <dfeng(a)redhat.com> --- mm/page_alloc.c | 16 +++++++++++++--- 1 files changed, 13 insertions(+), 3 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 50a6d10..ebf0af7 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -165,6 +165,7 @@ static char * const zone_names[MAX_NR_ZONES] = { "Movable", }; +static DEFINE_SPINLOCK(min_free_lock); int min_free_kbytes = 1024; static unsigned long __meminitdata nr_kernel_pages; @@ -4839,13 +4840,13 @@ static void setup_per_zone_lowmem_reserve(void) } /** - * setup_per_zone_wmarks - called when min_free_kbytes changes + * __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; @@ -4943,6 +4944,15 @@ static void __init setup_per_zone_inactive_ratio(void) calculate_zone_inactive_ratio(zone); } +void setup_per_zone_wmarks(void) +{ + unsigned long flags; + + spin_lock_irqsave(&min_free_lock, flags); + __setup_per_zone_wmarks(); + spin_unlock_irqrestore(&min_free_lock, flags); +} + /* * Initialise min_free_kbytes. * @@ -4978,7 +4988,7 @@ static int __init init_per_zone_wmark_min(void) min_free_kbytes = 128; if (min_free_kbytes > 65536) min_free_kbytes = 65536; - setup_per_zone_wmarks(); + __setup_per_zone_wmarks(); setup_per_zone_lowmem_reserve(); setup_per_zone_inactive_ratio(); return 0; -- 1.7.1.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |