mm/page_alloc: don't re-init pageset in zone_pcp_update() (169f6c19) · Commits · 戴 / test

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>

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

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