mm/hotplug: free zone->pageset when a zone becomes empty

When a zone becomes empty after memory offlining, free zone->pageset.
Otherwise it will cause memory leak when adding memory to the empty zone
again because build_all_zonelists() will allocate zone->pageset for an
empty zone.

Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Wei Wang <Bessel.Wang@huawei.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Keping Chen <chenkeping@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jiang Liu 2012-07-31 16:43:32 -07:00 committed by Linus Torvalds
parent 08dff7b7d6
commit 340175b7d1
3 changed files with 17 additions and 0 deletions

View file

@ -1331,6 +1331,7 @@ void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...);
extern void setup_per_cpu_pageset(void);
extern void zone_pcp_update(struct zone *zone);
extern void zone_pcp_reset(struct zone *zone);
/* nommu.c */
extern atomic_long_t mmap_pages_allocated;

View file

@ -966,6 +966,9 @@ repeat:
init_per_zone_wmark_min();
if (!populated_zone(zone))
zone_pcp_reset(zone);
if (!node_present_pages(node)) {
node_clear_state(node, N_HIGH_MEMORY);
kswapd_stop(node);

View file

@ -5894,6 +5894,19 @@ void free_contig_range(unsigned long pfn, unsigned nr_pages)
#endif
#ifdef CONFIG_MEMORY_HOTREMOVE
void zone_pcp_reset(struct zone *zone)
{
unsigned long flags;
/* avoid races with drain_pages() */
local_irq_save(flags);
if (zone->pageset != &boot_pageset) {
free_percpu(zone->pageset);
zone->pageset = &boot_pageset;
}
local_irq_restore(flags);
}
/*
* All pages in the range must be isolated before calling this.
*/