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authorMel Gorman <mel@csn.ul.ie>2011-01-13 15:45:43 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-13 17:32:31 -0800
commitb44129b30652c8771db2265939bb8b463724043d (patch)
treed5b669ff4faea020b03e894706f49d5d1ae56907 /mm/vmstat.c
parent88f5acf88ae6a9778f6d25d0d5d7ec2d57764a97 (diff)
mm: vmstat: use a single setter function and callback for adjusting percpu thresholds
reduce_pgdat_percpu_threshold() and restore_pgdat_percpu_threshold() exist to adjust the per-cpu vmstat thresholds while kswapd is awake to avoid errors due to counter drift. The functions duplicate some code so this patch replaces them with a single set_pgdat_percpu_threshold() that takes a callback function to calculate the desired threshold as a parameter. [akpm@linux-foundation.org: readability tweak] [kosaki.motohiro@jp.fujitsu.com: set_pgdat_percpu_threshold(): don't use for_each_online_cpu] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Christoph Lameter <cl@linux.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmstat.c')
-rw-r--r--mm/vmstat.c36
1 files changed, 7 insertions, 29 deletions
diff --git a/mm/vmstat.c b/mm/vmstat.c
index bc0f095791b..751a65e00aa 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -83,7 +83,7 @@ EXPORT_SYMBOL(vm_stat);
#ifdef CONFIG_SMP
-static int calculate_pressure_threshold(struct zone *zone)
+int calculate_pressure_threshold(struct zone *zone)
{
int threshold;
int watermark_distance;
@@ -107,7 +107,7 @@ static int calculate_pressure_threshold(struct zone *zone)
return threshold;
}
-static int calculate_threshold(struct zone *zone)
+int calculate_normal_threshold(struct zone *zone)
{
int threshold;
int mem; /* memory in 128 MB units */
@@ -166,7 +166,7 @@ static void refresh_zone_stat_thresholds(void)
for_each_populated_zone(zone) {
unsigned long max_drift, tolerate_drift;
- threshold = calculate_threshold(zone);
+ threshold = calculate_normal_threshold(zone);
for_each_online_cpu(cpu)
per_cpu_ptr(zone->pageset, cpu)->stat_threshold
@@ -185,46 +185,24 @@ static void refresh_zone_stat_thresholds(void)
}
}
-void reduce_pgdat_percpu_threshold(pg_data_t *pgdat)
+void set_pgdat_percpu_threshold(pg_data_t *pgdat,
+ int (*calculate_pressure)(struct zone *))
{
struct zone *zone;
int cpu;
int threshold;
int i;
- get_online_cpus();
- for (i = 0; i < pgdat->nr_zones; i++) {
- zone = &pgdat->node_zones[i];
- if (!zone->percpu_drift_mark)
- continue;
-
- threshold = calculate_pressure_threshold(zone);
- for_each_online_cpu(cpu)
- per_cpu_ptr(zone->pageset, cpu)->stat_threshold
- = threshold;
- }
- put_online_cpus();
-}
-
-void restore_pgdat_percpu_threshold(pg_data_t *pgdat)
-{
- struct zone *zone;
- int cpu;
- int threshold;
- int i;
-
- get_online_cpus();
for (i = 0; i < pgdat->nr_zones; i++) {
zone = &pgdat->node_zones[i];
if (!zone->percpu_drift_mark)
continue;
- threshold = calculate_threshold(zone);
- for_each_online_cpu(cpu)
+ threshold = (*calculate_pressure)(zone);
+ for_each_possible_cpu(cpu)
per_cpu_ptr(zone->pageset, cpu)->stat_threshold
= threshold;
}
- put_online_cpus();
}
/*