mm/free_pcppages_bulk: update pcp->count inside (77ba9062) · Commits · 戴 / test

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 <aaron.lu@intel.com> Suggested-by:

Matthew Wilcox <willy@infradead.org> Acked-by:

David Rientjes <rientjes@google.com> Acked-by:

Michal Hocko <mhocko@suse.com> Reviewed-by:

Andrew Morton <akpm@linux-foundation.org> Acked-by:

Vlastimil Babka <vbabka@suse.cz> Cc: Huang Ying <ying.huang@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kemi Wang <kemi.wang@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc.c

+3 −7

Original line number	Diff line number	Diff line
		@@ -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;
		}
		}

Admin message