Memcg has 2 eventcountes which counts "the same" event. Just usages are
different from each other. This patch tries to reduce event counter.
This patch's logic uses "only increment, no reset" new_counter and masks for each
checks. Softlimit chesk was done per 1000 events. So, the similar check
can be done by !(new_counter & 0x3ff). Threshold check was done per 100
events. So, the similar check can be done by (!new_counter & 0x7f)
Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
Cc: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
---
mm/memcontrol.c | 36 ++++++++++++------------------------
1 file changed, 12 insertions(+), 24 deletions(-)
Index: mmotm-2.6.33-Feb10/mm/memcontrol.c
===================================================================
--- mmotm-2.6.33-Feb10.orig/mm/memcontrol.c
+++ mmotm-2.6.33-Feb10/mm/memcontrol.c
@@ -63,8 +63,8 @@ static int really_do_swap_account __init
#define do_swap_account (0)
#endif
-#define SOFTLIMIT_EVENTS_THRESH (1000)
-#define THRESHOLDS_EVENTS_THRESH (100)
+#define SOFTLIMIT_EVENTS_THRESH (0x3ff) /* once in 1024 */
+#define THRESHOLDS_EVENTS_THRESH (0x7f) /* once in 128 */
/*
* Statistics for memory cgroup.
@@ -79,10 +79,7 @@ enum mem_cgroup_stat_index {
MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */
MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */
MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
- MEM_CGROUP_STAT_SOFTLIMIT, /* decrements on each page in/out.
- used by soft limit implementation */
- MEM_CGROUP_STAT_THRESHOLDS, /* decrements on each page in/out.
- used by threshold implementation */
+ MEM_CGROUP_EVENTS, /* incremented by 1 at pagein/pageout */
MEM_CGROUP_STAT_NSTATS,
};
@@ -394,16 +391,12 @@ mem_cgroup_remove_exceeded(struct mem_cg
static bool mem_cgroup_soft_limit_check(struct mem_cgroup *mem)
{
- bool ret = false;
s64 val;
- val = this_cpu_read(mem->stat->count[MEM_CGROUP_STAT_SOFTLIMIT]);
- if (unlikely(val < 0)) {
- this_cpu_write(mem->stat->count[MEM_CGROUP_STAT_SOFTLIMIT],
- SOFTLIMIT_EVENTS_THRESH);
- ret = true;
- }
- return ret;
+ val = this_cpu_read(mem->stat->count[MEM_CGROUP_EVENTS]);
+ if (unlikely(!(val & SOFTLIMIT_EVENTS_THRESH)))
+ return true;
+ return false;
}
static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
@@ -542,8 +535,7 @@ static void mem_cgroup_charge_statistics
__this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGIN_COUNT]);
else
__this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGOUT_COUNT]);
- __this_cpu_dec(mem->stat->count[MEM_CGROUP_STAT_SOFTLIMIT]);
- __this_cpu_dec(mem->stat->count[MEM_CGROUP_STAT_THRESHOLDS]);
+ __this_cpu_dec(mem->stat->count[MEM_CGROUP_EVENTS]);
preempt_enable();
}
@@ -3211,16 +3203,12 @@ static int mem_cgroup_swappiness_write(s
static bool mem_cgroup_threshold_check(struct mem_cgroup *mem)
{
- bool ret = false;
s64 val;
- val = this_cpu_read(mem->stat->count[MEM_CGROUP_STAT_THRESHOLDS]);
- if (unlikely(val < 0)) {
- this_cpu_write(mem->stat->count[MEM_CGROUP_STAT_THRESHOLDS],
- THRESHOLDS_EVENTS_THRESH);
- ret = true;
- }
- return ret;
+ val = this_cpu_read(mem->stat->count[MEM_CGROUP_EVENTS]);
+ if (unlikely(!(val & THRESHOLDS_EVENTS_THRESH)))
+ return true;
+ return false;
}
static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
--
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