From 6dcd73d7011ba9046f9b98e7f7c9d958f5810e6b Mon Sep 17 00:00:00 2001 From: Wen Congyang Date: Tue, 11 Dec 2012 16:01:01 -0800 Subject: [PATCH] memory-hotplug: allocate zone's pcp before onlining pages We use __free_page() to put a page to buddy system when onlining pages. __free_page() will store NR_FREE_PAGES in zone's pcp.vm_stat_diff, so we should allocate zone's pcp before onlining pages, otherwise we will lose some free pages. [mhocko@suse.cz: make zone_pcp_reset independent of MEMORY_HOTREMOVE] Signed-off-by: Wen Congyang Cc: David Rientjes Cc: Jiang Liu Cc: Len Brown Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Christoph Lameter Cc: Minchan Kim Cc: KOSAKI Motohiro Cc: Yasuaki Ishimatsu Cc: Dave Hansen Cc: Mel Gorman Signed-off-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory_hotplug.c | 8 ++++++-- mm/page_alloc.c | 2 +- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 0095d156324a..ec2f199cc5f7 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -498,12 +498,16 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages) * So, zonelist must be updated after online. */ mutex_lock(&zonelists_mutex); - if (!populated_zone(zone)) + if (!populated_zone(zone)) { need_zonelists_rebuild = 1; + build_all_zonelists(NULL, zone); + } ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages, online_pages_range); if (ret) { + if (need_zonelists_rebuild) + zone_pcp_reset(zone); mutex_unlock(&zonelists_mutex); printk(KERN_DEBUG "online_pages [mem %#010llx-%#010llx] failed\n", (unsigned long long) pfn << PAGE_SHIFT, @@ -519,7 +523,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages) if (onlined_pages) { node_set_state(zone_to_nid(zone), N_HIGH_MEMORY); if (need_zonelists_rebuild) - build_all_zonelists(NULL, zone); + build_all_zonelists(NULL, NULL); else zone_pcp_update(zone); } diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 4dba04f06880..5a7b7611d4e4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5983,7 +5983,6 @@ void __meminit zone_pcp_update(struct zone *zone) } #endif -#ifdef CONFIG_MEMORY_HOTREMOVE void zone_pcp_reset(struct zone *zone) { unsigned long flags; @@ -6003,6 +6002,7 @@ void zone_pcp_reset(struct zone *zone) local_irq_restore(flags); } +#ifdef CONFIG_MEMORY_HOTREMOVE /* * All pages in the range must be isolated before calling this. */ -- 2.20.1