mm/page_alloc: when handling percpu_pagelist_fraction, don't unneedly recalulate high

Simply moves calculation of the new 'high' value outside the
for_each_possible_cpu() loop, as it does not depend on the cpu.

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 6 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8125263be60f..386de0f11bea 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5575,7 +5575,6 @@ int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
  * cpu.  It is the fraction of total pages in each zone that a hot per cpu pagelist
  * can have before it gets flushed back to buddy allocator.
  */
-
 int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
         void __user *buffer, size_t *length, loff_t *ppos)
 {
@@ -5589,12 +5588,11 @@ int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
 
         mutex_lock(&pcp_batch_high_lock);
         for_each_populated_zone(zone) {
-                for_each_possible_cpu(cpu) {
-                        unsigned long  high;
-                        high = zone->managed_pages / percpu_pagelist_fraction;
+                unsigned long  high;
+                high = zone->managed_pages / percpu_pagelist_fraction;
+                for_each_possible_cpu(cpu)
                         setup_pagelist_highmark(
-                                per_cpu_ptr(zone->pageset, cpu), high);
-                }
+                                        per_cpu_ptr(zone->pageset, cpu), high);
         }
         mutex_unlock(&pcp_batch_high_lock);
         return 0;