Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8695949a authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
Browse files

[PATCH] Thin out scan_control: remove nr_to_scan and priority 



Make nr_to_scan and priority a parameter instead of putting it into scan
control.  This allows various small optimizations and IMHO makes the code
easier to read.

Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent a07fa394

mm/vmscan.c

+25 −34
Original line number Original line Diff line number Diff line
@@ -52,9 +52,6 @@ typedef enum { 
} pageout_t;

} pageout_t;





struct scan_control {

struct scan_control {

	/* Ask refill_inactive_zone, or shrink_cache to scan this many pages */

	unsigned long nr_to_scan;



	/* Incremented by the number of inactive pages that were scanned */

	/* Incremented by the number of inactive pages that were scanned */

	unsigned long nr_scanned;

	unsigned long nr_scanned;
@@ -63,9 +60,6 @@ struct scan_control { 




	unsigned long nr_mapped;	/* From page_state */

	unsigned long nr_mapped;	/* From page_state */





	/* Ask shrink_caches, or shrink_zone to scan at this priority */

	unsigned int priority;



	/* This context's GFP mask */

	/* This context's GFP mask */

	gfp_t gfp_mask;

	gfp_t gfp_mask;
@@ -1112,11 +1106,10 @@ static int isolate_lru_pages(int nr_to_scan, struct list_head *src, 
/*

/*

 * shrink_cache() adds the number of pages reclaimed to sc->nr_reclaimed

 * shrink_cache() adds the number of pages reclaimed to sc->nr_reclaimed

 */

 */

static void shrink_cache(struct zone *zone, struct scan_control *sc)

static void shrink_cache(int max_scan, struct zone *zone, struct scan_control *sc)

{

{

	LIST_HEAD(page_list);

	LIST_HEAD(page_list);

	struct pagevec pvec;

	struct pagevec pvec;

	int max_scan = sc->nr_to_scan;





	pagevec_init(&pvec, 1);

	pagevec_init(&pvec, 1);
@@ -1192,12 +1185,11 @@ done: 
 * But we had to alter page->flags anyway.

 * But we had to alter page->flags anyway.

 */

 */

static void

static void

refill_inactive_zone(struct zone *zone, struct scan_control *sc)

refill_inactive_zone(int nr_pages, struct zone *zone, struct scan_control *sc)

{

{

	int pgmoved;

	int pgmoved;

	int pgdeactivate = 0;

	int pgdeactivate = 0;

	int pgscanned;

	int pgscanned;

	int nr_pages = sc->nr_to_scan;

	LIST_HEAD(l_hold);	/* The pages which were snipped off */

	LIST_HEAD(l_hold);	/* The pages which were snipped off */

	LIST_HEAD(l_inactive);	/* Pages to go onto the inactive_list */

	LIST_HEAD(l_inactive);	/* Pages to go onto the inactive_list */

	LIST_HEAD(l_active);	/* Pages to go onto the active_list */

	LIST_HEAD(l_active);	/* Pages to go onto the active_list */
@@ -1332,10 +1324,11 @@ refill_inactive_zone(struct zone *zone, struct scan_control *sc) 
 * This is a basic per-zone page freer.  Used by both kswapd and direct reclaim.

 * This is a basic per-zone page freer.  Used by both kswapd and direct reclaim.

 */

 */

static void

static void

shrink_zone(struct zone *zone, struct scan_control *sc)

shrink_zone(int priority, struct zone *zone, struct scan_control *sc)

{

{

	unsigned long nr_active;

	unsigned long nr_active;

	unsigned long nr_inactive;

	unsigned long nr_inactive;

	unsigned long nr_to_scan;





	atomic_inc(&zone->reclaim_in_progress);

	atomic_inc(&zone->reclaim_in_progress);
@@ -1343,14 +1336,14 @@ shrink_zone(struct zone *zone, struct scan_control *sc) 
	 * Add one to `nr_to_scan' just to make sure that the kernel will

	 * Add one to `nr_to_scan' just to make sure that the kernel will

	 * slowly sift through the active list.

	 * slowly sift through the active list.

	 */

	 */

	zone->nr_scan_active += (zone->nr_active >> sc->priority) + 1;

	zone->nr_scan_active += (zone->nr_active >> priority) + 1;

	nr_active = zone->nr_scan_active;

	nr_active = zone->nr_scan_active;

	if (nr_active >= sc->swap_cluster_max)

	if (nr_active >= sc->swap_cluster_max)

		zone->nr_scan_active = 0;

		zone->nr_scan_active = 0;

	else

	else

		nr_active = 0;

		nr_active = 0;





	zone->nr_scan_inactive += (zone->nr_inactive >> sc->priority) + 1;

	zone->nr_scan_inactive += (zone->nr_inactive >> priority) + 1;

	nr_inactive = zone->nr_scan_inactive;

	nr_inactive = zone->nr_scan_inactive;

	if (nr_inactive >= sc->swap_cluster_max)

	if (nr_inactive >= sc->swap_cluster_max)

		zone->nr_scan_inactive = 0;

		zone->nr_scan_inactive = 0;
@@ -1359,17 +1352,17 @@ shrink_zone(struct zone *zone, struct scan_control *sc) 




	while (nr_active || nr_inactive) {

	while (nr_active || nr_inactive) {

		if (nr_active) {

		if (nr_active) {

			sc->nr_to_scan = min(nr_active,

			nr_to_scan = min(nr_active,

					(unsigned long)sc->swap_cluster_max);

					(unsigned long)sc->swap_cluster_max);

			nr_active -= sc->nr_to_scan;

			nr_active -= nr_to_scan;

			refill_inactive_zone(zone, sc);

			refill_inactive_zone(nr_to_scan, zone, sc);

		}

		}





		if (nr_inactive) {

		if (nr_inactive) {

			sc->nr_to_scan = min(nr_inactive,

			nr_to_scan = min(nr_inactive,

					(unsigned long)sc->swap_cluster_max);

					(unsigned long)sc->swap_cluster_max);

			nr_inactive -= sc->nr_to_scan;

			nr_inactive -= nr_to_scan;

			shrink_cache(zone, sc);

			shrink_cache(nr_to_scan, zone, sc);

		}

		}

	}

	}
@@ -1395,7 +1388,7 @@ shrink_zone(struct zone *zone, struct scan_control *sc) 
 * scan then give up on it.

 * scan then give up on it.

 */

 */

static void

static void

shrink_caches(struct zone **zones, struct scan_control *sc)

shrink_caches(int priority, struct zone **zones, struct scan_control *sc)

{

{

	int i;

	int i;
@@ -1408,14 +1401,14 @@ shrink_caches(struct zone **zones, struct scan_control *sc) 
		if (!cpuset_zone_allowed(zone, __GFP_HARDWALL))

		if (!cpuset_zone_allowed(zone, __GFP_HARDWALL))

			continue;

			continue;





		zone->temp_priority = sc->priority;

		zone->temp_priority = priority;

		if (zone->prev_priority > sc->priority)

		if (zone->prev_priority > priority)

			zone->prev_priority = sc->priority;

			zone->prev_priority = priority;





		if (zone->all_unreclaimable && sc->priority != DEF_PRIORITY)

		if (zone->all_unreclaimable && priority != DEF_PRIORITY)

			continue;	/* Let kswapd poll it */

			continue;	/* Let kswapd poll it */





		shrink_zone(zone, sc);

		shrink_zone(priority, zone, sc);

	}

	}

}

}
@@ -1462,11 +1455,10 @@ int try_to_free_pages(struct zone **zones, gfp_t gfp_mask) 
		sc.nr_mapped = read_page_state(nr_mapped);

		sc.nr_mapped = read_page_state(nr_mapped);

		sc.nr_scanned = 0;

		sc.nr_scanned = 0;

		sc.nr_reclaimed = 0;

		sc.nr_reclaimed = 0;

		sc.priority = priority;

		sc.swap_cluster_max = SWAP_CLUSTER_MAX;

		sc.swap_cluster_max = SWAP_CLUSTER_MAX;

		if (!priority)

		if (!priority)

			disable_swap_token();

			disable_swap_token();

		shrink_caches(zones, &sc);

		shrink_caches(priority, zones, &sc);

		shrink_slab(sc.nr_scanned, gfp_mask, lru_pages);

		shrink_slab(sc.nr_scanned, gfp_mask, lru_pages);

		if (reclaim_state) {

		if (reclaim_state) {

			sc.nr_reclaimed += reclaim_state->reclaimed_slab;

			sc.nr_reclaimed += reclaim_state->reclaimed_slab;
@@ -1629,9 +1621,8 @@ scan: 
				zone->prev_priority = priority;

				zone->prev_priority = priority;

			sc.nr_scanned = 0;

			sc.nr_scanned = 0;

			sc.nr_reclaimed = 0;

			sc.nr_reclaimed = 0;

			sc.priority = priority;

			sc.swap_cluster_max = nr_pages? nr_pages : SWAP_CLUSTER_MAX;

			sc.swap_cluster_max = nr_pages? nr_pages : SWAP_CLUSTER_MAX;

			shrink_zone(zone, &sc);

			shrink_zone(priority, zone, &sc);

			reclaim_state->reclaimed_slab = 0;

			reclaim_state->reclaimed_slab = 0;

			nr_slab = shrink_slab(sc.nr_scanned, GFP_KERNEL,

			nr_slab = shrink_slab(sc.nr_scanned, GFP_KERNEL,

						lru_pages);

						lru_pages);
@@ -1886,6 +1877,7 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) 
	struct scan_control sc;

	struct scan_control sc;

	cpumask_t mask;

	cpumask_t mask;

	int node_id;

	int node_id;

	int priority;





	if (time_before(jiffies,

	if (time_before(jiffies,

		zone->last_unsuccessful_zone_reclaim + zone_reclaim_interval))

		zone->last_unsuccessful_zone_reclaim + zone_reclaim_interval))
@@ -1906,7 +1898,6 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) 
	sc.may_swap = !!(zone_reclaim_mode & RECLAIM_SWAP);

	sc.may_swap = !!(zone_reclaim_mode & RECLAIM_SWAP);

	sc.nr_scanned = 0;

	sc.nr_scanned = 0;

	sc.nr_reclaimed = 0;

	sc.nr_reclaimed = 0;

	sc.priority = ZONE_RECLAIM_PRIORITY + 1;

	sc.nr_mapped = read_page_state(nr_mapped);

	sc.nr_mapped = read_page_state(nr_mapped);

	sc.gfp_mask = gfp_mask;

	sc.gfp_mask = gfp_mask;
@@ -1932,11 +1923,11 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) 
	 * Free memory by calling shrink zone with increasing priorities

	 * Free memory by calling shrink zone with increasing priorities

	 * until we have enough memory freed.

	 * until we have enough memory freed.

	 */

	 */

	priority = ZONE_RECLAIM_PRIORITY;

	do {

	do {

		sc.priority--;

		shrink_zone(priority, zone, &sc);

		shrink_zone(zone, &sc);

		priority--;



	} while (priority >= 0 && sc.nr_reclaimed < nr_pages);

	} while (sc.nr_reclaimed < nr_pages && sc.priority > 0);





	if (sc.nr_reclaimed < nr_pages && (zone_reclaim_mode & RECLAIM_SLAB)) {

	if (sc.nr_reclaimed < nr_pages && (zone_reclaim_mode & RECLAIM_SLAB)) {

		/*

		/*