From 77ba9062e43c7e4966d9ff3afd87dca86542f86a Mon Sep 17 00:00:00 2001 From: Aaron Lu Date: Thu, 5 Apr 2018 16:24:06 -0700 Subject: [PATCH] mm/free_pcppages_bulk: update pcp->count inside Matthew Wilcox found that all callers of free_pcppages_bulk() currently update pcp->count immediately after so it's natural to do it inside free_pcppages_bulk(). No functionality or performance change is expected from this patch. Link: http://lkml.kernel.org/r/20180301062845.26038-2-aaron.lu@intel.com Signed-off-by: Aaron Lu Suggested-by: Matthew Wilcox Acked-by: David Rientjes Acked-by: Michal Hocko Reviewed-by: Andrew Morton Acked-by: Vlastimil Babka Cc: Huang Ying Cc: Dave Hansen Cc: Kemi Wang Cc: Tim Chen Cc: Andi Kleen Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 86b7f0430e02..08c195cdf161 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1112,6 +1112,7 @@ static void free_pcppages_bulk(struct zone *zone, int count, page = list_last_entry(list, struct page, lru); /* must delete as __free_one_page list manipulates */ list_del(&page->lru); + pcp->count--; mt = get_pcppage_migratetype(page); /* MIGRATE_ISOLATE page should not go to pcplists */ @@ -2495,10 +2496,8 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) local_irq_save(flags); batch = READ_ONCE(pcp->batch); to_drain = min(pcp->count, batch); - if (to_drain > 0) { + if (to_drain > 0) free_pcppages_bulk(zone, to_drain, pcp); - pcp->count -= to_drain; - } local_irq_restore(flags); } #endif @@ -2520,10 +2519,8 @@ static void drain_pages_zone(unsigned int cpu, struct zone *zone) pset = per_cpu_ptr(zone->pageset, cpu); pcp = &pset->pcp; - if (pcp->count) { + if (pcp->count) free_pcppages_bulk(zone, pcp->count, pcp); - pcp->count = 0; - } local_irq_restore(flags); } @@ -2747,7 +2744,6 @@ static void free_unref_page_commit(struct page *page, unsigned long pfn) if (pcp->count >= pcp->high) { unsigned long batch = READ_ONCE(pcp->batch); free_pcppages_bulk(zone, batch, pcp); - pcp->count -= batch; } } -- 2.30.2