[PATCH v2 05/10] mm/page_alloc: when handling percpu_pagelist_fraction, don't unneedly recalulate high

From: Cody P Schafer
Date: Tue Apr 09 2013 - 19:30:51 EST


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@xxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4a03c56..50a277a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5502,7 +5502,6 @@ 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)
{
@@ -5516,12 +5515,11 @@ 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;
--
1.8.2

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