mm: page_alloc: calculate classzone_idx once from the zonelist ref

There is no need to calculate zone_idx(preferred_zone) multiple times
or use the pgdat to figure it out.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 09345ab7fb6382116e5621df99863cac60302a36..8f785b1534a31d84d4bd705ab65cb5b061466a28 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1916,11 +1916,10 @@ static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
 static struct page *
 get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
                struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
-               struct zone *preferred_zone, int migratetype)
+               struct zone *preferred_zone, int classzone_idx, int migratetype)
 {
        struct zoneref *z;
        struct page *page = NULL;
-       int classzone_idx;
        struct zone *zone;
        nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
        int zlc_active = 0;             /* set if using zonelist_cache */
@@ -1928,7 +1927,6 @@ get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
        bool consider_zone_dirty = (alloc_flags & ALLOC_WMARK_LOW) &&
                                (gfp_mask & __GFP_WRITE);
 
-       classzone_idx = zone_idx(preferred_zone);
 zonelist_scan:
        /*
         * Scan zonelist, looking for a zone with enough free.
@@ -2186,7 +2184,7 @@ static inline struct page *
 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
        struct zonelist *zonelist, enum zone_type high_zoneidx,
        nodemask_t *nodemask, struct zone *preferred_zone,
-       int migratetype)
+       int classzone_idx, int migratetype)
 {
        struct page *page;
 
@@ -2204,7 +2202,7 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
        page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
                order, zonelist, high_zoneidx,
                ALLOC_WMARK_HIGH|ALLOC_CPUSET,
-               preferred_zone, migratetype);
+               preferred_zone, classzone_idx, migratetype);
        if (page)
                goto out;
 
@@ -2239,7 +2237,7 @@ static struct page *
 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
        struct zonelist *zonelist, enum zone_type high_zoneidx,
        nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
-       int migratetype, enum migrate_mode mode,
+       int classzone_idx, int migratetype, enum migrate_mode mode,
        bool *contended_compaction, bool *deferred_compaction,
        unsigned long *did_some_progress)
 {
@@ -2267,7 +2265,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
                page = get_page_from_freelist(gfp_mask, nodemask,
                                order, zonelist, high_zoneidx,
                                alloc_flags & ~ALLOC_NO_WATERMARKS,
-                               preferred_zone, migratetype);
+                               preferred_zone, classzone_idx, migratetype);
                if (page) {
                        preferred_zone->compact_blockskip_flush = false;
                        compaction_defer_reset(preferred_zone, order, true);
@@ -2299,7 +2297,8 @@ static inline struct page *
 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
        struct zonelist *zonelist, enum zone_type high_zoneidx,
        nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
-       int migratetype, enum migrate_mode mode, bool *contended_compaction,
+       int classzone_idx, int migratetype,
+       enum migrate_mode mode, bool *contended_compaction,
        bool *deferred_compaction, unsigned long *did_some_progress)
 {
        return NULL;
@@ -2339,7 +2338,7 @@ static inline struct page *
 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
        struct zonelist *zonelist, enum zone_type high_zoneidx,
        nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
-       int migratetype, unsigned long *did_some_progress)
+       int classzone_idx, int migratetype, unsigned long *did_some_progress)
 {
        struct page *page = NULL;
        bool drained = false;
@@ -2357,7 +2356,8 @@ retry:
        page = get_page_from_freelist(gfp_mask, nodemask, order,
                                        zonelist, high_zoneidx,
                                        alloc_flags & ~ALLOC_NO_WATERMARKS,
-                                       preferred_zone, migratetype);
+                                       preferred_zone, classzone_idx,
+                                       migratetype);
 
        /*
         * If an allocation failed after direct reclaim, it could be because
@@ -2380,14 +2380,14 @@ static inline struct page *
 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
        struct zonelist *zonelist, enum zone_type high_zoneidx,
        nodemask_t *nodemask, struct zone *preferred_zone,
-       int migratetype)
+       int classzone_idx, int migratetype)
 {
        struct page *page;
 
        do {
                page = get_page_from_freelist(gfp_mask, nodemask, order,
                        zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
-                       preferred_zone, migratetype);
+                       preferred_zone, classzone_idx, migratetype);
 
                if (!page && gfp_mask & __GFP_NOFAIL)
                        wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
@@ -2488,7 +2488,7 @@ static inline struct page *
 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
        struct zonelist *zonelist, enum zone_type high_zoneidx,
        nodemask_t *nodemask, struct zone *preferred_zone,
-       int migratetype)
+       int classzone_idx, int migratetype)
 {
        const gfp_t wait = gfp_mask & __GFP_WAIT;
        struct page *page = NULL;
@@ -2537,15 +2537,18 @@ restart:
         * Find the true preferred zone if the allocation is unconstrained by
         * cpusets.
         */
-       if (!(alloc_flags & ALLOC_CPUSET) && !nodemask)
-               first_zones_zonelist(zonelist, high_zoneidx, NULL,
-                                       &preferred_zone);
+       if (!(alloc_flags & ALLOC_CPUSET) && !nodemask) {
+               struct zoneref *preferred_zoneref;
+               preferred_zoneref = first_zones_zonelist(zonelist, high_zoneidx,
+                               NULL, &preferred_zone);
+               classzone_idx = zonelist_zone_idx(preferred_zoneref);
+       }
 
 rebalance:
        /* This is the last chance, in general, before the goto nopage. */
        page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
                        high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
-                       preferred_zone, migratetype);
+                       preferred_zone, classzone_idx, migratetype);
        if (page)
                goto got_pg;
 
@@ -2560,7 +2563,7 @@ rebalance:
 
                page = __alloc_pages_high_priority(gfp_mask, order,
                                zonelist, high_zoneidx, nodemask,
-                               preferred_zone, migratetype);
+                               preferred_zone, classzone_idx, migratetype);
                if (page) {
                        goto got_pg;
                }
@@ -2591,7 +2594,8 @@ rebalance:
         */
        page = __alloc_pages_direct_compact(gfp_mask, order, zonelist,
                                        high_zoneidx, nodemask, alloc_flags,
-                                       preferred_zone, migratetype,
+                                       preferred_zone,
+                                       classzone_idx, migratetype,
                                        migration_mode, &contended_compaction,
                                        &deferred_compaction,
                                        &did_some_progress);
@@ -2621,7 +2625,8 @@ rebalance:
                                        zonelist, high_zoneidx,
                                        nodemask,
                                        alloc_flags, preferred_zone,
-                                       migratetype, &did_some_progress);
+                                       classzone_idx, migratetype,
+                                       &did_some_progress);
        if (page)
                goto got_pg;
 
@@ -2640,7 +2645,7 @@ rebalance:
                        page = __alloc_pages_may_oom(gfp_mask, order,
                                        zonelist, high_zoneidx,
                                        nodemask, preferred_zone,
-                                       migratetype);
+                                       classzone_idx, migratetype);
                        if (page)
                                goto got_pg;
 
@@ -2681,7 +2686,8 @@ rebalance:
                 */
                page = __alloc_pages_direct_compact(gfp_mask, order, zonelist,
                                        high_zoneidx, nodemask, alloc_flags,
-                                       preferred_zone, migratetype,
+                                       preferred_zone,
+                                       classzone_idx, migratetype,
                                        migration_mode, &contended_compaction,
                                        &deferred_compaction,
                                        &did_some_progress);
@@ -2708,10 +2714,12 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 {
        enum zone_type high_zoneidx = gfp_zone(gfp_mask);
        struct zone *preferred_zone;
+       struct zoneref *preferred_zoneref;
        struct page *page = NULL;
        int migratetype = allocflags_to_migratetype(gfp_mask);
        unsigned int cpuset_mems_cookie;
        int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR;
+       int classzone_idx;
 
        gfp_mask &= gfp_allowed_mask;
 
@@ -2734,11 +2742,12 @@ retry_cpuset:
        cpuset_mems_cookie = read_mems_allowed_begin();
 
        /* The preferred zone is used for statistics later */
-       first_zones_zonelist(zonelist, high_zoneidx,
+       preferred_zoneref = first_zones_zonelist(zonelist, high_zoneidx,
                                nodemask ? : &cpuset_current_mems_allowed,
                                &preferred_zone);
        if (!preferred_zone)
                goto out;
+       classzone_idx = zonelist_zone_idx(preferred_zoneref);
 
 #ifdef CONFIG_CMA
        if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
@@ -2748,7 +2757,7 @@ retry:
        /* First allocation attempt */
        page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
                        zonelist, high_zoneidx, alloc_flags,
-                       preferred_zone, migratetype);
+                       preferred_zone, classzone_idx, migratetype);
        if (unlikely(!page)) {
                /*
                 * The first pass makes sure allocations are spread
@@ -2774,7 +2783,7 @@ retry:
                gfp_mask = memalloc_noio_flags(gfp_mask);
                page = __alloc_pages_slowpath(gfp_mask, order,
                                zonelist, high_zoneidx, nodemask,
-                               preferred_zone, migratetype);
+                               preferred_zone, classzone_idx, migratetype);
        }
 
        trace_mm_page_alloc(page, order, gfp_mask, migratetype);