memcg: add memory.vmscan_stat
The commit log of 0ae5e89c60c9 ("memcg: count the soft_limit reclaim
in...") says it adds scanning stats to memory.stat file. But it doesn't
because we considered we needed to make a concensus for such new APIs.
This patch is a trial to add memory.scan_stat. This shows
- the number of scanned pages(total, anon, file)
- the number of rotated pages(total, anon, file)
- the number of freed pages(total, anon, file)
- the number of elaplsed time (including sleep/pause time)
for both of direct/soft reclaim.
The biggest difference with oringinal Ying's one is that this file
can be reset by some write, as
# echo 0 ...../memory.scan_stat
Example of output is here. This is a result after make -j 6 kernel
under 300M limit.
[kamezawa@bluextal ~]$ cat /cgroup/memory/A/memory.scan_stat
[kamezawa@bluextal ~]$ cat /cgroup/memory/A/memory.vmscan_stat
scanned_pages_by_limit 9471864
scanned_anon_pages_by_limit 6640629
scanned_file_pages_by_limit 2831235
rotated_pages_by_limit 4243974
rotated_anon_pages_by_limit 3971968
rotated_file_pages_by_limit 272006
freed_pages_by_limit 2318492
freed_anon_pages_by_limit 962052
freed_file_pages_by_limit 1356440
elapsed_ns_by_limit 351386416101
scanned_pages_by_system 0
scanned_anon_pages_by_system 0
scanned_file_pages_by_system 0
rotated_pages_by_system 0
rotated_anon_pages_by_system 0
rotated_file_pages_by_system 0
freed_pages_by_system 0
freed_anon_pages_by_system 0
freed_file_pages_by_system 0
elapsed_ns_by_system 0
scanned_pages_by_limit_under_hierarchy 9471864
scanned_anon_pages_by_limit_under_hierarchy 6640629
scanned_file_pages_by_limit_under_hierarchy 2831235
rotated_pages_by_limit_under_hierarchy 4243974
rotated_anon_pages_by_limit_under_hierarchy 3971968
rotated_file_pages_by_limit_under_hierarchy 272006
freed_pages_by_limit_under_hierarchy 2318492
freed_anon_pages_by_limit_under_hierarchy 962052
freed_file_pages_by_limit_under_hierarchy 1356440
elapsed_ns_by_limit_under_hierarchy 351386416101
scanned_pages_by_system_under_hierarchy 0
scanned_anon_pages_by_system_under_hierarchy 0
scanned_file_pages_by_system_under_hierarchy 0
rotated_pages_by_system_under_hierarchy 0
rotated_anon_pages_by_system_under_hierarchy 0
rotated_file_pages_by_system_under_hierarchy 0
freed_pages_by_system_under_hierarchy 0
freed_anon_pages_by_system_under_hierarchy 0
freed_file_pages_by_system_under_hierarchy 0
elapsed_ns_by_system_under_hierarchy 0
total_xxxx is for hierarchy management.
This will be useful for further memcg developments and need to be
developped before we do some complicated rework on LRU/softlimit
management.
This patch adds a new struct memcg_scanrecord into scan_control struct.
sc->nr_scanned at el is not designed for exporting information. For
example, nr_scanned is reset frequentrly and incremented +2 at scanning
mapped pages.
To avoid complexity, I added a new param in scan_control which is for
exporting scanning score.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Ying Han <yinghan@google.com>
Cc: Andrew Bresticker <abrestic@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/vmscan.c b/mm/vmscan.c
index f87702a..7ef6912 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -105,6 +105,7 @@
/* Which cgroup do we reclaim from */
struct mem_cgroup *mem_cgroup;
+ struct memcg_scanrecord *memcg_record;
/*
* Nodemask of nodes allowed by the caller. If NULL, all nodes
@@ -1348,6 +1349,8 @@
int file = is_file_lru(lru);
int numpages = hpage_nr_pages(page);
reclaim_stat->recent_rotated[file] += numpages;
+ if (!scanning_global_lru(sc))
+ sc->memcg_record->nr_rotated[file] += numpages;
}
if (!pagevec_add(&pvec, page)) {
spin_unlock_irq(&zone->lru_lock);
@@ -1391,6 +1394,10 @@
reclaim_stat->recent_scanned[0] += *nr_anon;
reclaim_stat->recent_scanned[1] += *nr_file;
+ if (!scanning_global_lru(sc)) {
+ sc->memcg_record->nr_scanned[0] += *nr_anon;
+ sc->memcg_record->nr_scanned[1] += *nr_file;
+ }
}
/*
@@ -1504,6 +1511,9 @@
nr_reclaimed += shrink_page_list(&page_list, zone, sc);
}
+ if (!scanning_global_lru(sc))
+ sc->memcg_record->nr_freed[file] += nr_reclaimed;
+
local_irq_disable();
if (current_is_kswapd())
__count_vm_events(KSWAPD_STEAL, nr_reclaimed);
@@ -1603,6 +1613,8 @@
}
reclaim_stat->recent_scanned[file] += nr_taken;
+ if (!scanning_global_lru(sc))
+ sc->memcg_record->nr_scanned[file] += nr_taken;
__count_zone_vm_events(PGREFILL, zone, pgscanned);
if (file)
@@ -1654,6 +1666,8 @@
* get_scan_ratio.
*/
reclaim_stat->recent_rotated[file] += nr_rotated;
+ if (!scanning_global_lru(sc))
+ sc->memcg_record->nr_rotated[file] += nr_rotated;
move_active_pages_to_lru(zone, &l_active,
LRU_ACTIVE + file * LRU_FILE);
@@ -2254,9 +2268,10 @@
#ifdef CONFIG_CGROUP_MEM_RES_CTLR
unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
- gfp_t gfp_mask, bool noswap,
- struct zone *zone,
- unsigned long *nr_scanned)
+ gfp_t gfp_mask, bool noswap,
+ struct zone *zone,
+ struct memcg_scanrecord *rec,
+ unsigned long *scanned)
{
struct scan_control sc = {
.nr_scanned = 0,
@@ -2266,7 +2281,9 @@
.may_swap = !noswap,
.order = 0,
.mem_cgroup = mem,
+ .memcg_record = rec,
};
+ unsigned long start, end;
sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
(GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK);
@@ -2275,6 +2292,7 @@
sc.may_writepage,
sc.gfp_mask);
+ start = sched_clock();
/*
* NOTE: Although we can get the priority field, using it
* here is not a good idea, since it limits the pages we can scan.
@@ -2283,19 +2301,25 @@
* the priority and make it zero.
*/
shrink_zone(0, zone, &sc);
+ end = sched_clock();
+
+ if (rec)
+ rec->elapsed += end - start;
+ *scanned = sc.nr_scanned;
trace_mm_vmscan_memcg_softlimit_reclaim_end(sc.nr_reclaimed);
- *nr_scanned = sc.nr_scanned;
return sc.nr_reclaimed;
}
unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
gfp_t gfp_mask,
- bool noswap)
+ bool noswap,
+ struct memcg_scanrecord *rec)
{
struct zonelist *zonelist;
unsigned long nr_reclaimed;
+ unsigned long start, end;
int nid;
struct scan_control sc = {
.may_writepage = !laptop_mode,
@@ -2304,6 +2328,7 @@
.nr_to_reclaim = SWAP_CLUSTER_MAX,
.order = 0,
.mem_cgroup = mem_cont,
+ .memcg_record = rec,
.nodemask = NULL, /* we don't care the placement */
.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
(GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK),
@@ -2312,6 +2337,7 @@
.gfp_mask = sc.gfp_mask,
};
+ start = sched_clock();
/*
* Unlike direct reclaim via alloc_pages(), memcg's reclaim doesn't
* take care of from where we get pages. So the node where we start the
@@ -2326,6 +2352,9 @@
sc.gfp_mask);
nr_reclaimed = do_try_to_free_pages(zonelist, &sc, &shrink);
+ end = sched_clock();
+ if (rec)
+ rec->elapsed += end - start;
trace_mm_vmscan_memcg_reclaim_end(nr_reclaimed);