xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

memory-hotplug: fix zone stat mismatch

Browse Source 
During memory-hotplug, I found NR_ISOLATED_[ANON|FILE] are increasing,
causing the kernel to hang.  When the system doesn't have enough free
pages, it enters reclaim but never reclaim any pages due to
too_many_isolated()==true and loops forever.

The cause is that when we do memory-hotadd after memory-remove,
__zone_pcp_update() clears a zone's ZONE_STAT_ITEMS in setup_pageset()
although the vm_stat_diff of all CPUs still have values.

In addtion, when we offline all pages of the zone, we reset them in
zone_pcp_reset without draining so we loss some zone stat item.

Reviewed-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Minchan Kim
2012-10-08 16:33:39 -07:00
committed by Linus Torvalds
parent 082708072a
commit 5a88381384
3 changed files with 23 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
mm/page_alloc.c
View File

@@ -5916,6 +5916,7 @@ static int __meminit __zone_pcp_update(void *data)
local_irq_save(flags);
if (pcp->count > 0)
free_pcppages_bulk(zone, pcp->count, pcp);
drain_zonestat(zone, pset);
setup_pageset(pset, batch);
local_irq_restore(flags);
}
@@ -5932,10 +5933,16 @@ void __meminit zone_pcp_update(struct zone *zone)
void zone_pcp_reset(struct zone *zone)
{
unsigned long flags;
int cpu;
struct per_cpu_pageset *pset;
/* avoid races with drain_pages() */
local_irq_save(flags);
if (zone->pageset != &boot_pageset) {
for_each_online_cpu(cpu) {
pset = per_cpu_ptr(zone->pageset, cpu);
drain_zonestat(zone, pset);
}
free_percpu(zone->pageset);
zone->pageset = &boot_pageset;
}