mm/page_alloc: don't re-init pageset in zone_pcp_update()

When memory hotplug is triggered, we call pageset_init() on
per-cpu-pagesets which both contain pages and are in use, causing both the
leakage of those pages and (potentially) bad behaviour if a page is
allocated from a pageset while it is being cleared.

Avoid this by factoring out pageset_set_high_and_batch() (which contains
all needed logic too set a pageset's ->high and ->batch inrespective of
system state) from zone_pageset_init() and using the new
pageset_set_high_and_batch() instead of zone_pageset_init() in
zone_pcp_update().

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Cody P Schafer 2013-07-03 15:01:41 -07:00 committed by Linus Torvalds
parent 3664033c56
commit 169f6c1999

View file

@ -4104,11 +4104,9 @@ static void pageset_set_high(struct per_cpu_pageset *p,
pageset_update(&p->pcp, high, batch);
}
static void __meminit zone_pageset_init(struct zone *zone, int cpu)
static void __meminit pageset_set_high_and_batch(struct zone *zone,
struct per_cpu_pageset *pcp)
{
struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
pageset_init(pcp);
if (percpu_pagelist_fraction)
pageset_set_high(pcp,
(zone->managed_pages /
@ -4117,6 +4115,14 @@ static void __meminit zone_pageset_init(struct zone *zone, int cpu)
pageset_set_batch(pcp, zone_batchsize(zone));
}
static void __meminit zone_pageset_init(struct zone *zone, int cpu)
{
struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
pageset_init(pcp);
pageset_set_high_and_batch(zone, pcp);
}
static void __meminit setup_zone_pageset(struct zone *zone)
{
int cpu;
@ -6100,7 +6106,8 @@ void __meminit zone_pcp_update(struct zone *zone)
unsigned cpu;
mutex_lock(&pcp_batch_high_lock);
for_each_possible_cpu(cpu)
zone_pageset_init(zone, cpu);
pageset_set_high_and_batch(zone,
per_cpu_ptr(zone->pageset, cpu));
mutex_unlock(&pcp_batch_high_lock);
}
#endif