From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <20080320202122.012158000@chello.nl> References: <20080320201042.675090000@chello.nl> Date: Thu, 20 Mar 2008 21:10:50 +0100 From: Peter Zijlstra Subject: [PATCH 08/30] mm: serialize access to min_free_kbytes Content-Disposition: inline; filename=mm-setup_per_zone_pages_min.patch Sender: owner-linux-mm@kvack.org Return-Path: To: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, trond.myklebust@fys.uio.no, neilb@suse.de, miklos@szeredi.hu, penberg@cs.helsinki.fi, a.p.zijlstra@chello.nl List-ID: There is a small race between the procfs caller and the memory hotplug caller of setup_per_zone_pages_min(). Not a big deal, but the next patch will add yet another caller. Time to close the gap. Signed-off-by: Peter Zijlstra --- mm/page_alloc.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) Index: linux-2.6/mm/page_alloc.c =================================================================== --- linux-2.6.orig/mm/page_alloc.c +++ linux-2.6/mm/page_alloc.c @@ -117,6 +117,7 @@ static char * const zone_names[MAX_NR_ZO "Movable", }; +static DEFINE_SPINLOCK(min_free_lock); int min_free_kbytes = 1024; unsigned long __meminitdata nr_kernel_pages; @@ -4180,12 +4181,12 @@ static void setup_per_zone_lowmem_reserv } /** - * setup_per_zone_pages_min - called when min_free_kbytes changes. + * __setup_per_zone_pages_min - called when min_free_kbytes changes. * * Ensures that the pages_{min,low,high} values for each zone are set correctly * with respect to min_free_kbytes. */ -void setup_per_zone_pages_min(void) +static void __setup_per_zone_pages_min(void) { unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); unsigned long lowmem_pages = 0; @@ -4240,6 +4241,15 @@ void setup_per_zone_pages_min(void) calculate_totalreserve_pages(); } +void setup_per_zone_pages_min(void) +{ + unsigned long flags; + + spin_lock_irqsave(&min_free_lock, flags); + __setup_per_zone_pages_min(); + spin_unlock_irqrestore(&min_free_lock, flags); +} + /* * Initialise min_free_kbytes. * @@ -4275,7 +4285,7 @@ static int __init init_per_zone_pages_mi min_free_kbytes = 128; if (min_free_kbytes > 65536) min_free_kbytes = 65536; - setup_per_zone_pages_min(); + __setup_per_zone_pages_min(); setup_per_zone_lowmem_reserve(); return 0; } -- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org