mm, page_alloc: remove field from alloc_context

The classzone_idx can be inferred from preferred_zoneref so remove the
unnecessary field and save stack space.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 5 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index dba8cfd0b2d6..9da66e792e17 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2771,7 +2771,7 @@ zonelist_scan:
 
                 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
                 if (!zone_watermark_fast(zone, order, mark,
-                                       ac->classzone_idx, alloc_flags)) {
+                                       ac_classzone_idx(ac), alloc_flags)) {
                         int ret;
 
                         /* Checked here to keep the fast path fast */
@@ -2794,7 +2794,7 @@ zonelist_scan:
                         default:
                                 /* did we reclaim enough */
                                 if (zone_watermark_ok(zone, order, mark,
-                                                ac->classzone_idx, alloc_flags))
+                                                ac_classzone_idx(ac), alloc_flags))
                                         goto try_this_zone;
 
                                 continue;
@@ -3114,7 +3114,7 @@ static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac)
 
         for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
                                                 ac->high_zoneidx, ac->nodemask)
-                wakeup_kswapd(zone, order, zonelist_zone_idx(ac->preferred_zoneref));
+                wakeup_kswapd(zone, order, ac_classzone_idx(ac));
 }
 
 static inline unsigned int
@@ -3422,8 +3422,6 @@ retry_cpuset:
                 goto no_zone;
         }
 
-        ac.classzone_idx = zonelist_zone_idx(ac.preferred_zoneref);
-
         /* First allocation attempt */
         page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
         if (likely(page))