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Commit e247dbce authored by KOSAKI Motohiro's avatar KOSAKI Motohiro Committed by Linus Torvalds
Browse files

vmscan: simplify shrink_inactive_list() 



Now, max_scan of shrink_inactive_list() is always passed less than
SWAP_CLUSTER_MAX.  then, we can remove scanning pages loop in it.  This
patch also help stack diet.

detail
 - remove "while (nr_scanned < max_scan)" loop
 - remove nr_freed (now, we use nr_reclaimed directly)
 - remove nr_scan (now, we use nr_scanned directly)
 - rename max_scan to nr_to_scan
 - pass nr_to_scan into isolate_pages() directly instead
   using SWAP_CLUSTER_MAX

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: default avatarMel Gorman <mel@csn.ul.ie>
Reviewed-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: default avatarRik van Riel <riel@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michael Rubin <mrubin@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 25edde03

mm/vmscan.c

+102 −110
Original line number Diff line number Diff line
@@ -1136,15 +1136,21 @@ static int too_many_isolated(struct zone *zone, int file, 
 * shrink_inactive_list() is a helper for shrink_zone().  It returns the number

 * of reclaimed pages

 */

static unsigned long shrink_inactive_list(unsigned long max_scan,

static unsigned long shrink_inactive_list(unsigned long nr_to_scan,

			struct zone *zone, struct scan_control *sc,

			int priority, int file)

{

	LIST_HEAD(page_list);

	struct pagevec pvec;

	unsigned long nr_scanned = 0;

	unsigned long nr_scanned;

	unsigned long nr_reclaimed = 0;

	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);

	struct page *page;

	unsigned long nr_taken;

	unsigned long nr_active;

	unsigned int count[NR_LRU_LISTS] = { 0, };

	unsigned long nr_anon;

	unsigned long nr_file;



	while (unlikely(too_many_isolated(zone, file, sc))) {

		congestion_wait(BLK_RW_ASYNC, HZ/10);
@@ -1159,33 +1165,25 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, 


	lru_add_drain();

	spin_lock_irq(&zone->lru_lock);

	do {

		struct page *page;

		unsigned long nr_taken;

		unsigned long nr_scan;

		unsigned long nr_freed;

		unsigned long nr_active;

		unsigned int count[NR_LRU_LISTS] = { 0, };

		int mode = sc->lumpy_reclaim_mode ? ISOLATE_BOTH : ISOLATE_INACTIVE;

		unsigned long nr_anon;

		unsigned long nr_file;



	if (scanning_global_lru(sc)) {

			nr_taken = isolate_pages_global(SWAP_CLUSTER_MAX,

							&page_list, &nr_scan,

							sc->order, mode,

		nr_taken = isolate_pages_global(nr_to_scan,

			&page_list, &nr_scanned, sc->order,

			sc->lumpy_reclaim_mode ?

				ISOLATE_BOTH : ISOLATE_INACTIVE,

			zone, 0, file);

			zone->pages_scanned += nr_scan;

		zone->pages_scanned += nr_scanned;

		if (current_is_kswapd())

			__count_zone_vm_events(PGSCAN_KSWAPD, zone,

						       nr_scan);

					       nr_scanned);

		else

			__count_zone_vm_events(PGSCAN_DIRECT, zone,

						       nr_scan);

					       nr_scanned);

	} else {

			nr_taken = mem_cgroup_isolate_pages(SWAP_CLUSTER_MAX,

							&page_list, &nr_scan,

							sc->order, mode,

		nr_taken = mem_cgroup_isolate_pages(nr_to_scan,

			&page_list, &nr_scanned, sc->order,

			sc->lumpy_reclaim_mode ?

				ISOLATE_BOTH : ISOLATE_INACTIVE,

			zone, sc->mem_cgroup,

			0, file);

		/*
@@ -1219,8 +1217,7 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, 


	spin_unlock_irq(&zone->lru_lock);



		nr_scanned += nr_scan;

		nr_freed = shrink_page_list(&page_list, sc, PAGEOUT_IO_ASYNC);

	nr_reclaimed = shrink_page_list(&page_list, sc, PAGEOUT_IO_ASYNC);



	/*

	 * If we are direct reclaiming for contiguous pages and we do
@@ -1228,7 +1225,7 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, 
	 * for IO to complete. This will stall high-order allocations

	 * but that should be acceptable to the caller

	 */

		if (nr_freed < nr_taken && !current_is_kswapd() &&

	if (nr_reclaimed < nr_taken && !current_is_kswapd() &&

			sc->lumpy_reclaim_mode) {

		congestion_wait(BLK_RW_ASYNC, HZ/10);
@@ -1239,16 +1236,13 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, 
		nr_active = clear_active_flags(&page_list, count);

		count_vm_events(PGDEACTIVATE, nr_active);



			nr_freed += shrink_page_list(&page_list, sc,

							PAGEOUT_IO_SYNC);

		nr_reclaimed += shrink_page_list(&page_list, sc, PAGEOUT_IO_SYNC);

	}



		nr_reclaimed += nr_freed;



	local_irq_disable();

	if (current_is_kswapd())

			__count_vm_events(KSWAPD_STEAL, nr_freed);

		__count_zone_vm_events(PGSTEAL, zone, nr_freed);

		__count_vm_events(KSWAPD_STEAL, nr_reclaimed);

	__count_zone_vm_events(PGSTEAL, zone, nr_reclaimed);



	spin_lock(&zone->lru_lock);

	/*
@@ -1281,8 +1275,6 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, 
	__mod_zone_page_state(zone, NR_ISOLATED_ANON, -nr_anon);

	__mod_zone_page_state(zone, NR_ISOLATED_FILE, -nr_file);



  	} while (nr_scanned < max_scan);



done:

	spin_unlock_irq(&zone->lru_lock);

	pagevec_release(&pvec);