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Commit 169f6c19 authored by Cody P Schafer's avatar Cody P Schafer Committed by Linus Torvalds
Browse files

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: default avatarCody P Schafer <cody@linux.vnet.ibm.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3664033c

mm/page_alloc.c

+12 −5
Original line number Diff line number Diff line
@@ -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