mm, vmscan: make shrink_node decisions more node-centric

Earlier patches focused on having direct reclaim and kswapd use data
that is node-centric for reclaiming but shrink_node() itself still uses
too much zone information.  This patch removes unnecessary zone-based
information with the most important decision being whether to continue
reclaim or not.  Some memcg APIs are adjusted as a result even though
memcg itself still uses some zone information.

[mgorman@techsingularity.net: optimization]
Link: http://lkml.kernel.org/r/1468588165-12461-2-git-send-email-mgorman@techsingularity.net
Link: http://lkml.kernel.org/r/1467970510-21195-14-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 6d2321c..f4963ee 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -324,22 +324,23 @@ mem_cgroup_zone_zoneinfo(struct mem_cgroup *memcg, struct zone *zone)
 }
 
 /**
- * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
+ * mem_cgroup_lruvec - get the lru list vector for a node or a memcg zone
+ * @node: node of the wanted lruvec
  * @zone: zone of the wanted lruvec
  * @memcg: memcg of the wanted lruvec
  *
- * Returns the lru list vector holding pages for the given @zone and
- * @mem.  This can be the global zone lruvec, if the memory controller
+ * Returns the lru list vector holding pages for a given @node or a given
+ * @memcg and @zone. This can be the node lruvec, if the memory controller
  * is disabled.
  */
-static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
-                                                   struct mem_cgroup *memcg)
+static inline struct lruvec *mem_cgroup_lruvec(struct pglist_data *pgdat,
+                               struct zone *zone, struct mem_cgroup *memcg)
 {
        struct mem_cgroup_per_zone *mz;
        struct lruvec *lruvec;
 
        if (mem_cgroup_disabled()) {
-               lruvec = zone_lruvec(zone);
+               lruvec = node_lruvec(pgdat);
                goto out;
        }
 
@@ -609,10 +610,10 @@ static inline void mem_cgroup_migrate(struct page *old, struct page *new)
 {
 }
 
-static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
-                                                   struct mem_cgroup *memcg)
+static inline struct lruvec *mem_cgroup_lruvec(struct pglist_data *pgdat,
+                               struct zone *zone, struct mem_cgroup *memcg)
 {
-       return zone_lruvec(zone);
+       return node_lruvec(pgdat);
 }
 
 static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 4062fa7..895c365 100644 (file)
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -739,9 +739,9 @@ static inline spinlock_t *zone_lru_lock(struct zone *zone)
        return &zone->zone_pgdat->lru_lock;
 }
 
-static inline struct lruvec *zone_lruvec(struct zone *zone)
+static inline struct lruvec *node_lruvec(struct pglist_data *pgdat)
 {
-       return &zone->zone_pgdat->lruvec;
+       return &pgdat->lruvec;
 }
 
 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 916e2ed..0ad616d 100644 (file)
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -316,7 +316,7 @@ extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
                                                  unsigned long nr_pages,
                                                  gfp_t gfp_mask,
                                                  bool may_swap);
-extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
+extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem,
                                                gfp_t gfp_mask, bool noswap,
                                                struct zone *zone,
                                                unsigned long *nr_scanned);

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 50c86ad..c9ebec9 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1432,8 +1432,8 @@ static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
                        }
                        continue;
                }
-               total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
-                                                    zone, &nr_scanned);
+               total += mem_cgroup_shrink_node(victim, gfp_mask, false,
+                                       zone, &nr_scanned);
                *total_scanned += nr_scanned;
                if (!soft_limit_excess(root_memcg))
                        break;

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8158641..749b3c3 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5911,6 +5911,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat)
 #endif
        pgdat_page_ext_init(pgdat);
        spin_lock_init(&pgdat->lru_lock);
+       lruvec_init(node_lruvec(pgdat));
 
        for (j = 0; j < MAX_NR_ZONES; j++) {
                struct zone *zone = pgdat->node_zones + j;
@@ -5973,7 +5974,6 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat)
                /* For bootup, initialized properly in watermark setup */
                mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages);
 
-               lruvec_init(zone_lruvec(zone));
                if (!size)
                        continue;
 

diff --git a/mm/vmscan.c b/mm/vmscan.c
index b7a276f..46f7a71 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2224,12 +2224,13 @@ static inline void init_tlb_ubc(void)
 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
 
 /*
- * This is a basic per-zone page freer.  Used by both kswapd and direct reclaim.
+ * This is a basic per-node page freer.  Used by both kswapd and direct reclaim.
  */
-static void shrink_zone_memcg(struct zone *zone, struct mem_cgroup *memcg,
+static void shrink_node_memcg(struct pglist_data *pgdat, struct mem_cgroup *memcg,
                              struct scan_control *sc, unsigned long *lru_pages)
 {
-       struct lruvec *lruvec = mem_cgroup_zone_lruvec(zone, memcg);
+       struct zone *zone = &pgdat->node_zones[sc->reclaim_idx];
+       struct lruvec *lruvec = mem_cgroup_lruvec(pgdat, zone, memcg);
        unsigned long nr[NR_LRU_LISTS];
        unsigned long targets[NR_LRU_LISTS];
        unsigned long nr_to_scan;
@@ -2362,13 +2363,14 @@ static bool in_reclaim_compaction(struct scan_control *sc)
  * calls try_to_compact_zone() that it will have enough free pages to succeed.
  * It will give up earlier than that if there is difficulty reclaiming pages.
  */
-static inline bool should_continue_reclaim(struct zone *zone,
+static inline bool should_continue_reclaim(struct pglist_data *pgdat,
                                        unsigned long nr_reclaimed,
                                        unsigned long nr_scanned,
                                        struct scan_control *sc)
 {
        unsigned long pages_for_compaction;
        unsigned long inactive_lru_pages;
+       int z;
 
        /* If not in reclaim/compaction mode, stop */
        if (!in_reclaim_compaction(sc))
@@ -2402,21 +2404,29 @@ static inline bool should_continue_reclaim(struct zone *zone,
         * inactive lists are large enough, continue reclaiming
         */
        pages_for_compaction = (2UL << sc->order);
-       inactive_lru_pages = node_page_state(zone->zone_pgdat, NR_INACTIVE_FILE);
+       inactive_lru_pages = node_page_state(pgdat, NR_INACTIVE_FILE);
        if (get_nr_swap_pages() > 0)
-               inactive_lru_pages += node_page_state(zone->zone_pgdat, NR_INACTIVE_ANON);
+               inactive_lru_pages += node_page_state(pgdat, NR_INACTIVE_ANON);
        if (sc->nr_reclaimed < pages_for_compaction &&
                        inactive_lru_pages > pages_for_compaction)
                return true;
 
        /* If compaction would go ahead or the allocation would succeed, stop */
-       switch (compaction_suitable(zone, sc->order, 0, 0)) {
-       case COMPACT_PARTIAL:
-       case COMPACT_CONTINUE:
-               return false;
-       default:
-               return true;
+       for (z = 0; z <= sc->reclaim_idx; z++) {
+               struct zone *zone = &pgdat->node_zones[z];
+               if (!populated_zone(zone))
+                       continue;
+
+               switch (compaction_suitable(zone, sc->order, 0, sc->reclaim_idx)) {
+               case COMPACT_PARTIAL:
+               case COMPACT_CONTINUE:
+                       return false;
+               default:
+                       /* check next zone */
+                       ;
+               }
        }
+       return true;
 }
 
 static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc,
@@ -2425,15 +2435,14 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc,
        struct reclaim_state *reclaim_state = current->reclaim_state;
        unsigned long nr_reclaimed, nr_scanned;
        bool reclaimable = false;
-       struct zone *zone = &pgdat->node_zones[classzone_idx];
 
        do {
                struct mem_cgroup *root = sc->target_mem_cgroup;
                struct mem_cgroup_reclaim_cookie reclaim = {
-                       .zone = zone,
+                       .zone = &pgdat->node_zones[classzone_idx],
                        .priority = sc->priority,
                };
-               unsigned long zone_lru_pages = 0;
+               unsigned long node_lru_pages = 0;
                struct mem_cgroup *memcg;
 
                nr_reclaimed = sc->nr_reclaimed;
@@ -2454,11 +2463,11 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc,
                        reclaimed = sc->nr_reclaimed;
                        scanned = sc->nr_scanned;
 
-                       shrink_zone_memcg(zone, memcg, sc, &lru_pages);
-                       zone_lru_pages += lru_pages;
+                       shrink_node_memcg(pgdat, memcg, sc, &lru_pages);
+                       node_lru_pages += lru_pages;
 
                        if (!global_reclaim(sc))
-                               shrink_slab(sc->gfp_mask, zone_to_nid(zone),
+                               shrink_slab(sc->gfp_mask, pgdat->node_id,
                                            memcg, sc->nr_scanned - scanned,
                                            lru_pages);
 
@@ -2470,7 +2479,7 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc,
                        /*
                         * Direct reclaim and kswapd have to scan all memory
                         * cgroups to fulfill the overall scan target for the
-                        * zone.
+                        * node.
                         *
                         * Limit reclaim, on the other hand, only cares about
                         * nr_to_reclaim pages to be reclaimed and it will
@@ -2489,9 +2498,9 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc,
                 * the eligible LRU pages were scanned.
                 */
                if (global_reclaim(sc))
-                       shrink_slab(sc->gfp_mask, zone_to_nid(zone), NULL,
+                       shrink_slab(sc->gfp_mask, pgdat->node_id, NULL,
                                    sc->nr_scanned - nr_scanned,
-                                   zone_lru_pages);
+                                   node_lru_pages);
 
                if (reclaim_state) {
                        sc->nr_reclaimed += reclaim_state->reclaimed_slab;
@@ -2506,7 +2515,7 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc,
                if (sc->nr_reclaimed - nr_reclaimed)
                        reclaimable = true;
 
-       } while (should_continue_reclaim(zone, sc->nr_reclaimed - nr_reclaimed,
+       } while (should_continue_reclaim(pgdat, sc->nr_reclaimed - nr_reclaimed,
                                         sc->nr_scanned - nr_scanned, sc));
 
        return reclaimable;
@@ -2906,7 +2915,7 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
 
 #ifdef CONFIG_MEMCG
 
-unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *memcg,
+unsigned long mem_cgroup_shrink_node(struct mem_cgroup *memcg,
                                                gfp_t gfp_mask, bool noswap,
                                                struct zone *zone,
                                                unsigned long *nr_scanned)
@@ -2931,11 +2940,11 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *memcg,
        /*
         * NOTE: Although we can get the priority field, using it
         * here is not a good idea, since it limits the pages we can scan.
-        * if we don't reclaim here, the shrink_zone from balance_pgdat
+        * if we don't reclaim here, the shrink_node from balance_pgdat
         * will pick up pages from other mem cgroup's as well. We hack
         * the priority and make it zero.
         */
-       shrink_zone_memcg(zone, memcg, &sc, &lru_pages);
+       shrink_node_memcg(zone->zone_pgdat, memcg, &sc, &lru_pages);
 
        trace_mm_vmscan_memcg_softlimit_reclaim_end(sc.nr_reclaimed);
 
@@ -2994,7 +3003,7 @@ static void age_active_anon(struct pglist_data *pgdat,
 
        memcg = mem_cgroup_iter(NULL, NULL, NULL);
        do {
-               struct lruvec *lruvec = mem_cgroup_zone_lruvec(zone, memcg);
+               struct lruvec *lruvec = mem_cgroup_lruvec(pgdat, zone, memcg);
 
                if (inactive_list_is_low(lruvec, false))
                        shrink_active_list(SWAP_CLUSTER_MAX, lruvec,

diff --git a/mm/workingset.c b/mm/workingset.c
index 7820a7e..df0daca 100644 (file)
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -218,7 +218,7 @@ void *workingset_eviction(struct address_space *mapping, struct page *page)
        VM_BUG_ON_PAGE(page_count(page), page);
        VM_BUG_ON_PAGE(!PageLocked(page), page);
 
-       lruvec = mem_cgroup_zone_lruvec(zone, memcg);
+       lruvec = mem_cgroup_lruvec(zone->zone_pgdat, zone, memcg);
        eviction = atomic_long_inc_return(&lruvec->inactive_age);
        return pack_shadow(memcgid, zone, eviction);
 }
@@ -267,7 +267,7 @@ bool workingset_refault(void *shadow)
                rcu_read_unlock();
                return false;
        }
-       lruvec = mem_cgroup_zone_lruvec(zone, memcg);
+       lruvec = mem_cgroup_lruvec(zone->zone_pgdat, zone, memcg);
        refault = atomic_long_read(&lruvec->inactive_age);
        active_file = lruvec_lru_size(lruvec, LRU_ACTIVE_FILE);
        rcu_read_unlock();
@@ -319,7 +319,7 @@ void workingset_activation(struct page *page)
        memcg = page_memcg_rcu(page);
        if (!mem_cgroup_disabled() && !memcg)
                goto out;
-       lruvec = mem_cgroup_zone_lruvec(page_zone(page), memcg);
+       lruvec = mem_cgroup_lruvec(page_pgdat(page), page_zone(page), memcg);
        atomic_long_inc(&lruvec->inactive_age);
 out:
        rcu_read_unlock();