The patch titled
mm: vmstat: use a single setter function and callback for adjusting percpu thresholds
has been added to the -mm tree. Its filename is
mm-vmstat-use-a-single-setter-function-and-callback-for-adjusting-percpu-thresholds.patch
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Subject: mm: vmstat: use a single setter function and callback for adjusting percpu thresholds
From: Mel Gorman <mel@xxxxxxxxx>
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.
Signed-off-by: Mel Gorman <mel@xxxxxxxxx>
Reviewed-by: Christoph Lameter <cl@xxxxxxxxx>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/vmstat.h | 10 ++++++----
mm/vmscan.c | 6 ++++--
mm/vmstat.c | 32 ++++++--------------------------
3 files changed, 16 insertions(+), 32 deletions(-)
diff -puN include/linux/vmstat.h~mm-vmstat-use-a-single-setter-function-and-callback-for-adjusting-percpu-thresholds include/linux/vmstat.h
--- a/include/linux/vmstat.h~mm-vmstat-use-a-single-setter-function-and-callback-for-adjusting-percpu-thresholds
+++ a/include/linux/vmstat.h
@@ -254,8 +254,11 @@ extern void dec_zone_state(struct zone *
extern void __dec_zone_state(struct zone *, enum zone_stat_item);
void refresh_cpu_vm_stats(int);
-void reduce_pgdat_percpu_threshold(pg_data_t *pgdat);
-void restore_pgdat_percpu_threshold(pg_data_t *pgdat);
+
+int calculate_pressure_threshold(struct zone *zone);
+int calculate_normal_threshold(struct zone *zone);
+void set_pgdat_percpu_threshold(pg_data_t *pgdat,
+ int (*calculate_pressure)(struct zone *));
#else /* CONFIG_SMP */
/*
@@ -300,8 +303,7 @@ static inline void __dec_zone_page_state
#define dec_zone_page_state __dec_zone_page_state
#define mod_zone_page_state __mod_zone_page_state
-static inline void reduce_pgdat_percpu_threshold(pg_data_t *pgdat) { }
-static inline void restore_pgdat_percpu_threshold(pg_data_t *pgdat) { }
+#define set_pgdat_percpu_threshold(pgdat, callback) { }
static inline void refresh_cpu_vm_stats(int cpu) { }
#endif
diff -puN mm/vmscan.c~mm-vmstat-use-a-single-setter-function-and-callback-for-adjusting-percpu-thresholds mm/vmscan.c
--- a/mm/vmscan.c~mm-vmstat-use-a-single-setter-function-and-callback-for-adjusting-percpu-thresholds
+++ a/mm/vmscan.c
@@ -2441,9 +2441,11 @@ static int kswapd(void *p)
*/
if (!sleeping_prematurely(pgdat, order, remaining)) {
trace_mm_vmscan_kswapd_sleep(pgdat->node_id);
- restore_pgdat_percpu_threshold(pgdat);
+ set_pgdat_percpu_threshold(pgdat,
+ calculate_normal_threshold);
schedule();
- reduce_pgdat_percpu_threshold(pgdat);
+ set_pgdat_percpu_threshold(pgdat,
+ calculate_pressure_threshold);
} else {
if (remaining)
count_vm_event(KSWAPD_LOW_WMARK_HIT_QUICKLY);
diff -puN mm/vmstat.c~mm-vmstat-use-a-single-setter-function-and-callback-for-adjusting-percpu-thresholds mm/vmstat.c
--- a/mm/vmstat.c~mm-vmstat-use-a-single-setter-function-and-callback-for-adjusting-percpu-thresholds
+++ a/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(
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
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
@@ -185,7 +185,8 @@ static void refresh_zone_stat_thresholds
}
}
-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;
@@ -198,28 +199,7 @@ void reduce_pgdat_percpu_threshold(pg_da
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);
+ threshold = calculate_pressure(zone);
for_each_online_cpu(cpu)
per_cpu_ptr(zone->pageset, cpu)->stat_threshold
= threshold;
_
Patches currently in -mm which might be from mel@xxxxxxxxx are
origin.patch
linux-next.patch
mm-page-allocator-adjust-the-per-cpu-counter-threshold-when-memory-is-low.patch
mm-vmstat-use-a-single-setter-function-and-callback-for-adjusting-percpu-thresholds.patch
add-debugging-aid-for-memory-initialisation-problems.patch
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