Merge "mm: vmscan: fix the page state calculation in too_many_isolated" (54cff1d8) · Commits · e / devices / samsung / android_kernel_samsung_msm8916

mm/vmscan.c

+49 −19

Original line number	Diff line number	Diff line
		@@ -1343,31 +1343,32 @@ int isolate_lru_page(struct page *page)
		return ret;
		}

		/*
		* A direct reclaimer may isolate SWAP_CLUSTER_MAX pages from the LRU list and
		* then get resheduled. When there are massive number of tasks doing page
		* allocation, such sleeping direct reclaimers may keep piling up on each CPU,
		* the LRU list will go small and be scanned faster than necessary, leading to
		* unnecessary swapping, thrashing and OOM.
		*/
		static int too_many_isolated(struct zone *zone, int file,
		struct scan_control *sc)
		static int __too_many_isolated(struct zone *zone, int file,
		struct scan_control *sc, int safe)
		{
		unsigned long inactive, isolated;

		if (current_is_kswapd())
		return 0;

		if (!global_reclaim(sc))
		return 0;

		if (file) {
		if (safe) {
		inactive = zone_page_state_snapshot(zone,
		NR_INACTIVE_FILE);
		isolated = zone_page_state_snapshot(zone,
		NR_ISOLATED_FILE);
		} else {
		inactive = zone_page_state(zone, NR_INACTIVE_FILE);
		isolated = zone_page_state(zone, NR_ISOLATED_FILE);
		}
		} else {
		if (safe) {
		inactive = zone_page_state_snapshot(zone,
		NR_INACTIVE_ANON);
		isolated = zone_page_state_snapshot(zone,
		NR_ISOLATED_ANON);
		} else {
		inactive = zone_page_state(zone, NR_INACTIVE_ANON);
		isolated = zone_page_state(zone, NR_ISOLATED_ANON);
		}
		}

		/*
		* GFP_NOIO/GFP_NOFS callers are allowed to isolate more pages, so they
		@@ -1380,6 +1381,32 @@ static int too_many_isolated(struct zone *zone, int file,
		return isolated > inactive;
		}

		/*
		* A direct reclaimer may isolate SWAP_CLUSTER_MAX pages from the LRU list and
		* then get resheduled. When there are massive number of tasks doing page
		* allocation, such sleeping direct reclaimers may keep piling up on each CPU,
		* the LRU list will go small and be scanned faster than necessary, leading to
		* unnecessary swapping, thrashing and OOM.
		*/
		static int too_many_isolated(struct zone *zone, int file,
		struct scan_control *sc, int safe)
		{
		if (current_is_kswapd())
		return 0;

		if (!global_reclaim(sc))
		return 0;

		if (unlikely(__too_many_isolated(zone, file, sc, 0))) {
		if (safe)
		return __too_many_isolated(zone, file, sc, safe);
		else
		return 1;
		}

		return 0;
		}

		static noinline_for_stack void
		putback_inactive_pages(struct lruvec lruvec, struct list_head page_list)
		{
		@@ -1453,15 +1480,18 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
		unsigned long nr_immediate = 0;
		isolate_mode_t isolate_mode = 0;
		int file = is_file_lru(lru);
		int safe = 0;
		struct zone *zone = lruvec_zone(lruvec);
		struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat;

		while (unlikely(too_many_isolated(zone, file, sc))) {
		while (unlikely(too_many_isolated(zone, file, sc, safe))) {
		congestion_wait(BLK_RW_ASYNC, HZ/10);

		/* We are about to die and free our memory. Return now. */
		if (fatal_signal_pending(current))
		return SWAP_CLUSTER_MAX;

		safe = 1;
		}

		lru_add_drain();