Memory controller: add per cgroup LRU and reclaim

Add the page_cgroup to the per cgroup LRU.  The reclaim algorithm has
been modified to make the isolate_lru_pages() as a pluggable component.  The
scan_control data structure now accepts the cgroup on behalf of which
reclaims are carried out.  try_to_free_pages() has been extended to become
cgroup aware.

[[email protected]: fix warning]
[[email protected]: initialize all scan_control's isolate_pages member]
[[email protected]: make do_try_to_free_pages() static]
[[email protected]: memcgroup: fix try_to_free order]
[[email protected]: this unlock_page_cgroup() is unnecessary]
Signed-off-by: Pavel Emelianov <[email protected]>
Signed-off-by: Balbir Singh <[email protected]>
Cc: Paul Menage <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Nick Piggin <[email protected]>
Cc: Kirill Korotaev <[email protected]>
Cc: Herbert Poetzl <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Vaidyanathan Srinivasan <[email protected]>
Signed-off-by: Lee Schermerhorn <[email protected]>
Signed-off-by: Hugh Dickins <[email protected]>
Signed-off-by: KAMEZAWA Hiroyuki <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

mm/vmscan.c

@@ -37,6 +37,7 @@
 #include <linux/delay.h>
 #include <linux/kthread.h>
 #include <linux/freezer.h>
+#include <linux/memcontrol.h>
 
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
@@ -68,6 +69,15 @@ struct scan_control {
 	int all_unreclaimable;
 
 	int order;
+
+	/* Which cgroup do we reclaim from */
+	struct mem_cgroup *mem_cgroup;
+
+	/* Pluggable isolate pages callback */
+	unsigned long (*isolate_pages)(unsigned long nr, struct list_head *dst,
+			unsigned long *scanned, int order, int mode,
+			struct zone *z, struct mem_cgroup *mem_cont,
+			int active);
 };
 
 #define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))
@@ -626,7 +636,7 @@ keep:
  *
  * returns 0 on success, -ve errno on failure.
  */
-static int __isolate_lru_page(struct page *page, int mode)
+int __isolate_lru_page(struct page *page, int mode)
 {
 	int ret = -EINVAL;
 
@@ -760,6 +770,21 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 	return nr_taken;
 }
 
+static unsigned long isolate_pages_global(unsigned long nr,
+					struct list_head *dst,
+					unsigned long *scanned, int order,
+					int mode, struct zone *z,
+					struct mem_cgroup *mem_cont,
+					int active)
+{
+	if (active)
+		return isolate_lru_pages(nr, &z->active_list, dst,
+						scanned, order, mode);
+	else
+		return isolate_lru_pages(nr, &z->inactive_list, dst,
+						scanned, order, mode);
+}
+
 /*
  * clear_active_flags() is a helper for shrink_active_list(), clearing
  * any active bits from the pages in the list.
@@ -801,11 +826,11 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
 		unsigned long nr_freed;
 		unsigned long nr_active;
 
-		nr_taken = isolate_lru_pages(sc->swap_cluster_max,
-			     &zone->inactive_list,
+		nr_taken = sc->isolate_pages(sc->swap_cluster_max,
 			     &page_list, &nr_scan, sc->order,
 			     (sc->order > PAGE_ALLOC_COSTLY_ORDER)?
-					     ISOLATE_BOTH : ISOLATE_INACTIVE);
+					     ISOLATE_BOTH : ISOLATE_INACTIVE,
+				zone, sc->mem_cgroup, 0);
 		nr_active = clear_active_flags(&page_list);
 		__count_vm_events(PGDEACTIVATE, nr_active);
 
@@ -1018,8 +1043,9 @@ force_reclaim_mapped:
 
 	lru_add_drain();
 	spin_lock_irq(&zone->lru_lock);
-	pgmoved = isolate_lru_pages(nr_pages, &zone->active_list,
-			    &l_hold, &pgscanned, sc->order, ISOLATE_ACTIVE);
+	pgmoved = sc->isolate_pages(nr_pages, &l_hold, &pgscanned, sc->order,
+					ISOLATE_ACTIVE, zone,
+					sc->mem_cgroup, 1);
 	zone->pages_scanned += pgscanned;
 	__mod_zone_page_state(zone, NR_ACTIVE, -pgmoved);
 	spin_unlock_irq(&zone->lru_lock);
@@ -1051,6 +1077,7 @@ force_reclaim_mapped:
 		ClearPageActive(page);
 
 		list_move(&page->lru, &zone->inactive_list);
+		mem_cgroup_move_lists(page_get_page_cgroup(page), false);
 		pgmoved++;
 		if (!pagevec_add(&pvec, page)) {
 			__mod_zone_page_state(zone, NR_INACTIVE, pgmoved);
@@ -1079,6 +1106,7 @@ force_reclaim_mapped:
 		SetPageLRU(page);
 		VM_BUG_ON(!PageActive(page));
 		list_move(&page->lru, &zone->active_list);
+		mem_cgroup_move_lists(page_get_page_cgroup(page), true);
 		pgmoved++;
 		if (!pagevec_add(&pvec, page)) {
 			__mod_zone_page_state(zone, NR_ACTIVE, pgmoved);
@@ -1206,7 +1234,8 @@ static unsigned long shrink_zones(int priority, struct zone **zones,
  * holds filesystem locks which prevent writeout this might not work, and the
  * allocation attempt will fail.
  */
-unsigned long try_to_free_pages(struct zone **zones, int order, gfp_t gfp_mask)
+static unsigned long do_try_to_free_pages(struct zone **zones, gfp_t gfp_mask,
+					  struct scan_control *sc)
 {
 	int priority;
 	int ret = 0;
@@ -1215,14 +1244,6 @@ unsigned long try_to_free_pages(struct zone **zones, int order, gfp_t gfp_mask)
 	struct reclaim_state *reclaim_state = current->reclaim_state;
 	unsigned long lru_pages = 0;
 	int i;
-	struct scan_control sc = {
-		.gfp_mask = gfp_mask,
-		.may_writepage = !laptop_mode,
-		.swap_cluster_max = SWAP_CLUSTER_MAX,
-		.may_swap = 1,
-		.swappiness = vm_swappiness,
-		.order = order,
-	};
 
 	count_vm_event(ALLOCSTALL);
 
@@ -1237,17 +1258,22 @@ unsigned long try_to_free_pages(struct zone **zones, int order, gfp_t gfp_mask)
 	}
 
 	for (priority = DEF_PRIORITY; priority >= 0; priority--) {
-		sc.nr_scanned = 0;
+		sc->nr_scanned = 0;
 		if (!priority)
 			disable_swap_token();
-		nr_reclaimed += shrink_zones(priority, zones, &sc);
-		shrink_slab(sc.nr_scanned, gfp_mask, lru_pages);
+		nr_reclaimed += shrink_zones(priority, zones, sc);
+		/*
+		 * Don't shrink slabs when reclaiming memory from
+		 * over limit cgroups
+		 */
+		if (sc->mem_cgroup == NULL)
+			shrink_slab(sc->nr_scanned, gfp_mask, lru_pages);
 		if (reclaim_state) {
 			nr_reclaimed += reclaim_state->reclaimed_slab;
 			reclaim_state->reclaimed_slab = 0;
 		}
-		total_scanned += sc.nr_scanned;
-		if (nr_reclaimed >= sc.swap_cluster_max) {
+		total_scanned += sc->nr_scanned;
+		if (nr_reclaimed >= sc->swap_cluster_max) {
 			ret = 1;
 			goto out;
 		}
@@ -1259,18 +1285,18 @@ unsigned long try_to_free_pages(struct zone **zones, int order, gfp_t gfp_mask)
 		 * that's undesirable in laptop mode, where we *want* lumpy
 		 * writeout.  So in laptop mode, write out the whole world.
 		 */
-		if (total_scanned > sc.swap_cluster_max +
-					sc.swap_cluster_max / 2) {
+		if (total_scanned > sc->swap_cluster_max +
+					sc->swap_cluster_max / 2) {
 			wakeup_pdflush(laptop_mode ? 0 : total_scanned);
-			sc.may_writepage = 1;
+			sc->may_writepage = 1;
 		}
 
 		/* Take a nap, wait for some writeback to complete */
-		if (sc.nr_scanned && priority < DEF_PRIORITY - 2)
+		if (sc->nr_scanned && priority < DEF_PRIORITY - 2)
 			congestion_wait(WRITE, HZ/10);
 	}
 	/* top priority shrink_caches still had more to do? don't OOM, then */
-	if (!sc.all_unreclaimable)
+	if (!sc->all_unreclaimable && sc->mem_cgroup == NULL)
 		ret = 1;
 out:
 	/*
@@ -1293,6 +1319,54 @@ out:
 	return ret;
 }
 
+unsigned long try_to_free_pages(struct zone **zones, int order, gfp_t gfp_mask)
+{
+	struct scan_control sc = {
+		.gfp_mask = gfp_mask,
+		.may_writepage = !laptop_mode,
+		.swap_cluster_max = SWAP_CLUSTER_MAX,
+		.may_swap = 1,
+		.swappiness = vm_swappiness,
+		.order = order,
+		.mem_cgroup = NULL,
+		.isolate_pages = isolate_pages_global,
+	};
+
+	return do_try_to_free_pages(zones, gfp_mask, &sc);
+}
+
+#ifdef CONFIG_CGROUP_MEM_CONT
+
+#ifdef CONFIG_HIGHMEM
+#define ZONE_USERPAGES ZONE_HIGHMEM
+#else
+#define ZONE_USERPAGES ZONE_NORMAL
+#endif
+
+unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont)
+{
+	struct scan_control sc = {
+		.gfp_mask = GFP_KERNEL,
+		.may_writepage = !laptop_mode,
+		.may_swap = 1,
+		.swap_cluster_max = SWAP_CLUSTER_MAX,
+		.swappiness = vm_swappiness,
+		.order = 0,
+		.mem_cgroup = mem_cont,
+		.isolate_pages = mem_cgroup_isolate_pages,
+	};
+	int node;
+	struct zone **zones;
+
+	for_each_online_node(node) {
+		zones = NODE_DATA(node)->node_zonelists[ZONE_USERPAGES].zones;
+		if (do_try_to_free_pages(zones, sc.gfp_mask, &sc))
+			return 1;
+	}
+	return 0;
+}
+#endif
+
 /*
  * For kswapd, balance_pgdat() will work across all this node's zones until
  * they are all at pages_high.
@@ -1328,6 +1402,8 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order)
 		.swap_cluster_max = SWAP_CLUSTER_MAX,
 		.swappiness = vm_swappiness,
 		.order = order,
+		.mem_cgroup = NULL,
+		.isolate_pages = isolate_pages_global,
 	};
 	/*
 	 * temp_priority is used to remember the scanning priority at which
@@ -1649,6 +1725,7 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
 		.swap_cluster_max = nr_pages,
 		.may_writepage = 1,
 		.swappiness = vm_swappiness,
+		.isolate_pages = isolate_pages_global,
 	};
 
 	current->reclaim_state = &reclaim_state;
@@ -1834,6 +1911,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
 					SWAP_CLUSTER_MAX),
 		.gfp_mask = gfp_mask,
 		.swappiness = vm_swappiness,
+		.isolate_pages = isolate_pages_global,
 	};
 	unsigned long slab_reclaimable;