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References: <20110616124730.d6960b8b.kamezawa.hiroyu@jp.fujitsu.com>
	<20110616125314.4f78b1e0.kamezawa.hiroyu@jp.fujitsu.com>
	<BANLkTim-r6ejJK601rWq7smY37FC9um7mg@mail.gmail.com>
Date: Mon, 20 Jun 2011 23:52:21 -0700
Message-ID: <BANLkTimFBdg7zo=NbDDA2DLxagM_FCgmDA@mail.gmail.com>
Subject: Re: [PATCH 3/7] memcg: add memory.scan_stat
From: Ying Han <yinghan@google.com>
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Sender: owner-linux-mm@kvack.org
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To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "akpm@linux-foundation.org" <akpm@linux-foundation.org>, "nishimura@mxp.nes.nec.co.jp" <nishimura@mxp.nes.nec.co.jp>, "bsingharora@gmail.com" <bsingharora@gmail.com>, Michal Hocko <mhocko@suse.cz>, "hannes@cmpxchg.org" <hannes@cmpxchg.org>

On Mon, Jun 20, 2011 at 11:49 PM, Ying Han <yinghan@google.com> wrote:
>
>
> On Wed, Jun 15, 2011 at 8:53 PM, KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fu=
jitsu.com> wrote:
>>
>> From e08990dd9ada13cf236bec1ef44b207436434b8e Mon Sep 17 00:00:00 2001
>> From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>> Date: Wed, 15 Jun 2011 14:11:01 +0900
>> Subject: [PATCH 3/7] memcg: add memory.scan_stat
>>
>> commit log of commit 0ae5e89 " 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
>> =A0- the number of scanned pages
>> =A0- the number of recleimed pages
>> =A0- the number of elaplsed time (including sleep/pause time)
>> =A0for both of direct/soft reclaim and shrinking caused by changing limi=
t
>> =A0or force_empty.
>>
>> The biggest difference with oringinal Ying's one is that this file
>> can be reset by some write, as
>>
>> =A0# echo 0 ...../memory.scan_stat
>>
>> [kamezawa@bluextal ~]$ cat /cgroup/memory/A/memory.scan_stat
>> scanned_pages_by_limit 358470
>> freed_pages_by_limit 180795
>> elapsed_ns_by_limit 21629927
>> scanned_pages_by_system 0
>> freed_pages_by_system 0
>> elapsed_ns_by_system 0
>> scanned_pages_by_shrink 76646
>> freed_pages_by_shrink 38355
>> elappsed_ns_by_shrink 31990670
>
> elapsed?
>
>>
>> total_scanned_pages_by_limit 358470
>> total_freed_pages_by_limit 180795
>> total_elapsed_ns_by_hierarchical 216299275
>> total_scanned_pages_by_system 0
>> total_freed_pages_by_system 0
>> total_elapsed_ns_by_system 0
>> total_scanned_pages_by_shrink 76646
>> total_freed_pages_by_shrink 38355
>> total_elapsed_ns_by_shrink 31990670
>>
>> total_xxxx is for hierarchy management.
>
> For some reason, i feel the=A0opposite where the local stat (like "scanne=
d_pages_by_limit") are reclaimed under hierarchical reclaim. The total_xxx =
stats are only incremented for root_mem which is the cgroup triggers the hi=
erarchical reclaim. So:
> total_scanned_pages_by_limit: number of pages being scanned while the mem=
cg hits its limit
> scanned_pages_by_limit: number of pages being scanned while one of the me=
mcg's=A0ancestor hits its limit
> am i missing something?
>
>>
>> This will be useful for further memcg developments and need to be
>> developped before we do some complicated rework on LRU/softlimit
>> management.
>>
>> Now, scan/free/elapsed_by_system is incomplete but future works of
>> Johannes at el. will fill remaining information and then, we can
>> look into problems of isolation between memcgs.
>>
>> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>> ---
>> =A0Documentation/cgroups/memory.txt | =A0 33 +++++++++
>> =A0include/linux/memcontrol.h =A0 =A0 =A0 | =A0 16 ++++
>> =A0include/linux/swap.h =A0 =A0 =A0 =A0 =A0 =A0 | =A0 =A06 -
>> =A0mm/memcontrol.c =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0| =A0135 +++++++++=
++++++++++++++++++++++++++++--
>> =A0mm/vmscan.c =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0| =A0 27 +++++=
+-
>> =A05 files changed, 199 insertions(+), 18 deletions(-)
>>
>> Index: mmotm-0615/Documentation/cgroups/memory.txt
>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>> --- mmotm-0615.orig/Documentation/cgroups/memory.txt
>> +++ mmotm-0615/Documentation/cgroups/memory.txt
>> @@ -380,7 +380,7 @@ will be charged as a new owner of it.
>>
>> =A05.2 stat file
>>
>> -memory.stat file includes following statistics
>> +5.2.1 memory.stat file includes following statistics
>>
>> =A0# per-memory cgroup local status
>> =A0cache =A0 =A0 =A0 =A0 =A0- # of bytes of page cache memory.
>> @@ -438,6 +438,37 @@ Note:
>> =A0 =A0 =A0 =A0 file_mapped is accounted only when the memory cgroup is =
owner of page
>> =A0 =A0 =A0 =A0 cache.)
>>
>> +5.2.2 memory.scan_stat
>> +
>> +memory.scan_stat includes statistics information for memory scanning an=
d
>> +freeing, reclaiming. The statistics shows memory scanning information s=
ince
>> +memory cgroup creation and can be reset to 0 by writing 0 as
>> +
>> + #echo 0 > ../memory.scan_stat
>> +
>> +This file contains following statistics.
>> +
>> +scanned_pages_by_limit - # of scanned pages at hitting limit.
>> +freed_pages_by_limit =A0 - # of freed pages at hitting limit.
>> +elapsed_ns_by_limit =A0 =A0- nano sec of elappsed time at LRU scan at
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0hit=
ting limit.(this includes sleep time.)
>
> elapsed?
>>
>> +
>> +scanned_pages_by_system =A0 =A0 =A0 =A0- # of scanned pages by the kern=
el.
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 (Now, this value means=
 global memory reclaim
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 caused by system m=
emory shortage with a hint
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0of softlimit. "No s=
oft limit" case will be
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0supported in future=
.)
>> +freed_pages_by_system =A0- # of freed pages by the kernel.
>> +elapsed_ns_by_system =A0 - nano sec of elappsed time by kernel.
>> +
>> +scanned_pages_by_shrink =A0 =A0 =A0 =A0- # of scanned pages by shrinkin=
g.
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 (i.e. =
changes of limit, force_empty, etc.)
>> +freed_pages_by_shrink =A0- # of freed pages by shirkining.
>> +elappsed_ns_by_shrink =A0- nano sec of elappsed time at shrinking.
>
> elapsed?
>>
>> +
>> +total_xxx includes the statistics of children scanning caused by the cg=
roup.
>
> based on the code inspection, the total_xxx also includes the cgroup's sc=
an stat as well.
>>
>> +
>> +
>> =A05.3 swappiness
>>
>> =A0Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of grou=
ps only.
>> Index: mmotm-0615/include/linux/memcontrol.h
>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>> --- mmotm-0615.orig/include/linux/memcontrol.h
>> +++ mmotm-0615/include/linux/memcontrol.h
>> @@ -120,6 +120,22 @@ struct zone_reclaim_stat*
>> =A0mem_cgroup_get_reclaim_stat_from_page(struct page *page);
>> =A0extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0struct task_struct *p);
>> +struct memcg_scanrecord {
>> + =A0 =A0 =A0 struct mem_cgroup *mem; /* scanend memory cgroup */
>> + =A0 =A0 =A0 struct mem_cgroup *root; /* scan target hierarchy root */
>> + =A0 =A0 =A0 int context; =A0 =A0 =A0 =A0 =A0 =A0/* scanning context (s=
ee memcontrol.c) */
>> + =A0 =A0 =A0 unsigned long nr_scanned; /* the number of scanned pages *=
/
>> + =A0 =A0 =A0 unsigned long nr_freed; /* the number of freed pages */
>> + =A0 =A0 =A0 unsigned long elappsed; /* nsec of time elapsed while scan=
ning */
>
> elapsed?
>>
>> +};
>> +
>> +extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *me=
m,
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 =A0 gfp_t gfp_mask, bool noswap,
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 =A0 struct memcg_scanrecord *rec);
>> +extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem=
,
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 gfp_t gfp_mask, bool noswap,
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 struct zone *zone,
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 struct memcg_scanrecord *rec);
>>
>> =A0#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
>> =A0extern int do_swap_account;
>> Index: mmotm-0615/include/linux/swap.h
>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>> --- mmotm-0615.orig/include/linux/swap.h
>> +++ mmotm-0615/include/linux/swap.h
>> @@ -253,12 +253,6 @@ static inline void lru_cache_add_file(st
>> =A0/* linux/mm/vmscan.c */
>> =A0extern unsigned long try_to_free_pages(struct zonelist *zonelist, int=
 order,
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0gfp_t gfp_mask, nodemask_t *mask);
>> -extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *me=
m,
>> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 =A0 gfp_t gfp_mask, bool noswap);
>> -extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem=
,
>> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 gfp_t gfp_mask, bool noswap,
>> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 struct zone *zone,
>> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 unsigned long *nr_scanned);
>> =A0extern int __isolate_lru_page(struct page *page, int mode, int file);
>> =A0extern unsigned long shrink_all_memory(unsigned long nr_pages);
>> =A0extern int vm_swappiness;
>> Index: mmotm-0615/mm/memcontrol.c
>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>> --- mmotm-0615.orig/mm/memcontrol.c
>> +++ mmotm-0615/mm/memcontrol.c
>> @@ -203,6 +203,57 @@ struct mem_cgroup_eventfd_list {
>> =A0static void mem_cgroup_threshold(struct mem_cgroup *mem);
>> =A0static void mem_cgroup_oom_notify(struct mem_cgroup *mem);
>>
>> +enum {
>> + =A0 =A0 =A0 SCAN_BY_LIMIT,
>> + =A0 =A0 =A0 FREED_BY_LIMIT,
>> + =A0 =A0 =A0 ELAPSED_BY_LIMIT,
>> +
>> + =A0 =A0 =A0 SCAN_BY_SYSTEM,
>> + =A0 =A0 =A0 FREED_BY_SYSTEM,
>> + =A0 =A0 =A0 ELAPSED_BY_SYSTEM,
>> +
>> + =A0 =A0 =A0 SCAN_BY_SHRINK,
>> + =A0 =A0 =A0 FREED_BY_SHRINK,
>> + =A0 =A0 =A0 ELAPSED_BY_SHRINK,
>> + =A0 =A0 =A0 NR_SCANSTATS,
>> +};
>> +#define __FREED =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0(1)
>> +#define =A0 =A0 =A0 =A0__ELAPSED =A0 =A0 =A0 (2)
>
> /tab/space/
>
>>
>> +
>> +struct scanstat {
>> + =A0 =A0 =A0 spinlock_t =A0 =A0 =A0lock;
>> + =A0 =A0 =A0 unsigned long =A0 stats[NR_SCANSTATS]; =A0 =A0/* local sta=
tistics */
>> + =A0 =A0 =A0 unsigned long =A0 totalstats[NR_SCANSTATS]; =A0 /* hierarc=
hical */
>> +};
>> +
>> +const char *scanstat_string[NR_SCANSTATS] =3D {
>> + =A0 =A0 =A0 "scanned_pages_by_limit",
>> + =A0 =A0 =A0 "freed_pages_by_limit",
>> + =A0 =A0 =A0 "elapsed_ns_by_limit",
>> +
>> + =A0 =A0 =A0 "scanned_pages_by_system",
>> + =A0 =A0 =A0 "freed_pages_by_system",
>> + =A0 =A0 =A0 "elapsed_ns_by_system",
>> +
>> + =A0 =A0 =A0 "scanned_pages_by_shrink",
>> + =A0 =A0 =A0 "freed_pages_by_shrink",
>> + =A0 =A0 =A0 "elappsed_ns_by_shrink",
>
> elapsed?
>>
>> +};
>> +
>> +const char *total_scanstat_string[NR_SCANSTATS] =3D {
>> + =A0 =A0 =A0 "total_scanned_pages_by_limit",
>> + =A0 =A0 =A0 "total_freed_pages_by_limit",
>> + =A0 =A0 =A0 "total_elapsed_ns_by_hierarchical",
>
> typo?
>
>>
>> +
>> + =A0 =A0 =A0 "total_scanned_pages_by_system",
>> + =A0 =A0 =A0 "total_freed_pages_by_system",
>> + =A0 =A0 =A0 "total_elapsed_ns_by_system",
>> +
>> + =A0 =A0 =A0 "total_scanned_pages_by_shrink",
>> + =A0 =A0 =A0 "total_freed_pages_by_shrink",
>> + =A0 =A0 =A0 "total_elapsed_ns_by_shrink",
>> +};
>> +
>> =A0/*
>> =A0* The memory controller data structure. The memory controller control=
s both
>> =A0* page cache and RSS per cgroup. We would eventually like to provide
>> @@ -264,7 +315,8 @@ struct mem_cgroup {
>>
>> =A0 =A0 =A0 =A0/* For oom notifier event fd */
>> =A0 =A0 =A0 =A0struct list_head oom_notify;
>> -
>> + =A0 =A0 =A0 /* For recording LRU-scan statistics */
>> + =A0 =A0 =A0 struct scanstat scanstat;
>> =A0 =A0 =A0 =A0/*
>> =A0 =A0 =A0 =A0 * Should we move charges of a task when a task is moved =
into this
>> =A0 =A0 =A0 =A0 * mem_cgroup ? And what type of charges should we move ?
>> @@ -1634,6 +1686,28 @@ int mem_cgroup_select_victim_node(struct
>> =A0}
>> =A0#endif
>>
>> +
>> +
>> +static void mem_cgroup_record_scanstat(struct memcg_scanrecord *rec)
>> +{
>> + =A0 =A0 =A0 struct mem_cgroup *mem;
>> + =A0 =A0 =A0 int context =3D rec->context;
>> +
>> + =A0 =A0 =A0 mem =3D rec->mem;
>> + =A0 =A0 =A0 spin_lock(&mem->scanstat.lock);
>> + =A0 =A0 =A0 mem->scanstat.stats[context] +=3D rec->nr_scanned;
>> + =A0 =A0 =A0 mem->scanstat.stats[context + __FREED] +=3D rec->nr_freed;
>> + =A0 =A0 =A0 mem->scanstat.stats[context + __ELAPSED] +=3D rec->elappse=
d;
>
> elapsed?
>
>> + =A0 =A0 =A0 spin_unlock(&mem->scanstat.lock);
>> +
>> + =A0 =A0 =A0 mem =3D rec->root;
>> + =A0 =A0 =A0 spin_lock(&mem->scanstat.lock);
>> + =A0 =A0 =A0 mem->scanstat.totalstats[context] +=3D rec->nr_scanned;
>> + =A0 =A0 =A0 mem->scanstat.totalstats[context + __FREED] +=3D rec->nr_f=
reed;
>> + =A0 =A0 =A0 mem->scanstat.totalstats[context + __ELAPSED] +=3D rec->el=
appsed;
>
> elapsed?
>>
>> + =A0 =A0 =A0 spin_unlock(&mem->scanstat.lock);
>> +}
>> +
>> =A0/*
>> =A0* Scan the hierarchy if needed to reclaim memory. We remember the las=
t child
>> =A0* we reclaimed from, so that we don't end up penalizing one child ext=
ensively
>> @@ -1659,8 +1733,8 @@ static int mem_cgroup_hierarchical_recla
>> =A0 =A0 =A0 =A0bool shrink =3D reclaim_options & MEM_CGROUP_RECLAIM_SHRI=
NK;
>> =A0 =A0 =A0 =A0bool check_soft =3D reclaim_options & MEM_CGROUP_RECLAIM_=
SOFT;
>> =A0 =A0 =A0 =A0unsigned long excess;
>> - =A0 =A0 =A0 unsigned long nr_scanned;
>> =A0 =A0 =A0 =A0int visit;
>> + =A0 =A0 =A0 struct memcg_scanrecord rec;
>>
>> =A0 =A0 =A0 =A0excess =3D res_counter_soft_limit_excess(&root_mem->res) =
>> PAGE_SHIFT;
>>
>> @@ -1668,6 +1742,15 @@ static int mem_cgroup_hierarchical_recla
>> =A0 =A0 =A0 =A0if (!check_soft && root_mem->memsw_is_minimum)
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0noswap =3D true;
>>
>> + =A0 =A0 =A0 if (shrink)
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 rec.context =3D SCAN_BY_SHRINK;
>> + =A0 =A0 =A0 else if (check_soft)
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 rec.context =3D SCAN_BY_SYSTEM;
>> + =A0 =A0 =A0 else
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 rec.context =3D SCAN_BY_LIMIT;
>> +
>> + =A0 =A0 =A0 rec.root =3D root_mem;
>
>
>
>>
>> +
>> =A0again:
>> =A0 =A0 =A0 =A0if (!shrink) {
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0visit =3D 0;
>> @@ -1695,14 +1778,19 @@ again:
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0css_put(&victim->css);
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0continue;
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0}
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 rec.mem =3D victim;
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 rec.nr_scanned =3D 0;
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 rec.nr_freed =3D 0;
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 rec.elappsed =3D 0;
>
> elapsed?
>>
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0/* we use swappiness of local cgroup */
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0if (check_soft) {
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret =3D mem_cgroup_shrink=
_node_zone(victim, gfp_mask,
>> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 noswap, zo=
ne, &nr_scanned);
>> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 *total_scanned +=3D nr_sca=
nned;
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 noswap, zo=
ne, &rec);
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 *total_scanned +=3D rec.nr=
_scanned;
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0} else
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret =3D try_to_free_mem_c=
group_pages(victim, gfp_mask,
>> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 noswap);
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 noswap, &rec);
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 mem_cgroup_record_scanstat(&rec);
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0css_put(&victim->css);
>>
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0total +=3D ret;
>> @@ -3757,7 +3845,8 @@ try_to_free:
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret =3D -EINTR;
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0goto out;
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0}
>> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 progress =3D try_to_free_mem_cgroup_pages(=
mem, GFP_KERNEL, false);
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 progress =3D try_to_free_mem_cgroup_pages(=
mem,
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 GFP_KERNEL=
, false, NULL);
>
> So we don't record the stat for force_empty case?
>
>>
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0if (!progress) {
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0nr_retries--;
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0/* maybe some writeback i=
s necessary */
>> @@ -4599,6 +4688,34 @@ static int mem_control_numa_stat_open(st
>> =A0}
>> =A0#endif /* CONFIG_NUMA */
>>
>> +static int mem_cgroup_scan_stat_read(struct cgroup *cgrp,
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 struct cft=
ype *cft,
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 struct cgr=
oup_map_cb *cb)
>> +{
>> + =A0 =A0 =A0 struct mem_cgroup *mem =3D mem_cgroup_from_cont(cgrp);
>> + =A0 =A0 =A0 int i;
>> +
>> + =A0 =A0 =A0 for (i =3D 0; i < NR_SCANSTATS; i++)
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 cb->fill(cb, scanstat_string[i], mem->scan=
stat.stats[i]);
>> + =A0 =A0 =A0 for (i =3D 0; i < NR_SCANSTATS; i++)
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 cb->fill(cb, total_scanstat_string[i],
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 mem->scanstat.totalstats[i=
]);
>> + =A0 =A0 =A0 return 0;
>> +}
>> +
>> +static int mem_cgroup_reset_scan_stat(struct cgroup *cgrp,
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 unsigned i=
nt event)
>> +{
>> + =A0 =A0 =A0 struct mem_cgroup *mem =3D mem_cgroup_from_cont(cgrp);
>> +
>> + =A0 =A0 =A0 spin_lock(&mem->scanstat.lock);
>> + =A0 =A0 =A0 memset(&mem->scanstat.stats, 0, sizeof(mem->scanstat.stats=
));
>> + =A0 =A0 =A0 memset(&mem->scanstat.totalstats, 0, sizeof(mem->scanstat.=
totalstats));
>> + =A0 =A0 =A0 spin_unlock(&mem->scanstat.lock);
>> + =A0 =A0 =A0 return 0;
>> +}
>> +
>> +
>> =A0static struct cftype mem_cgroup_files[] =3D {
>> =A0 =A0 =A0 =A0{
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0.name =3D "usage_in_bytes",
>> @@ -4669,6 +4786,11 @@ static struct cftype mem_cgroup_files[]
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0.mode =3D S_IRUGO,
>> =A0 =A0 =A0 =A0},
>> =A0#endif
>> + =A0 =A0 =A0 {
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 .name =3D "scan_stat",
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 .read_map =3D mem_cgroup_scan_stat_read,
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 .trigger =3D mem_cgroup_reset_scan_stat,
>> + =A0 =A0 =A0 },
>> =A0};
>>
>> =A0#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
>> @@ -4932,6 +5054,7 @@ mem_cgroup_create(struct cgroup_subsys *
>> =A0 =A0 =A0 =A0atomic_set(&mem->refcnt, 1);
>> =A0 =A0 =A0 =A0mem->move_charge_at_immigrate =3D 0;
>> =A0 =A0 =A0 =A0mutex_init(&mem->thresholds_lock);
>> + =A0 =A0 =A0 spin_lock_init(&mem->scanstat.lock);
>> =A0 =A0 =A0 =A0return &mem->css;
>> =A0free_out:
>> =A0 =A0 =A0 =A0__mem_cgroup_free(mem);
>> Index: mmotm-0615/mm/vmscan.c
>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>> --- mmotm-0615.orig/mm/vmscan.c
>> +++ mmotm-0615/mm/vmscan.c
>> @@ -2199,9 +2199,9 @@ unsigned long try_to_free_pages(struct z
>> =A0#ifdef CONFIG_CGROUP_MEM_RES_CTLR
>>
>> =A0unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
>> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 gfp_t gfp_mask, bool noswap,
>> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 struct zone *zone,
>> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 unsigned long *nr_scanned)
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 gfp_t gfp_mask, bool noswap,
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 struct zone *zone,
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 struct memcg_scanrecord *rec)
>> =A0{
>> =A0 =A0 =A0 =A0struct scan_control sc =3D {
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0.nr_scanned =3D 0,
>> @@ -2213,6 +2213,7 @@ unsigned long mem_cgroup_shrink_node_zon
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0.order =3D 0,
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0.mem_cgroup =3D mem,
>> =A0 =A0 =A0 =A0};
>> + =A0 =A0 =A0 unsigned long start, end;
>>
>> =A0 =A0 =A0 =A0sc.gfp_mask =3D (gfp_mask & GFP_RECLAIM_MASK) |
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0(GFP_HIGHUSER_MOVABLE & ~=
GFP_RECLAIM_MASK);
>> @@ -2221,6 +2222,7 @@ unsigned long mem_cgroup_shrink_node_zon
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0sc.may_writepage,
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0sc.gfp_mask);
>>
>> + =A0 =A0 =A0 start =3D sched_clock();
>> =A0 =A0 =A0 =A0/*
>> =A0 =A0 =A0 =A0 * NOTE: Although we can get the priority field, using it
>> =A0 =A0 =A0 =A0 * here is not a good idea, since it limits the pages we =
can scan.
>> @@ -2229,19 +2231,27 @@ unsigned long mem_cgroup_shrink_node_zon
>> =A0 =A0 =A0 =A0 * the priority and make it zero.
>> =A0 =A0 =A0 =A0 */
>> =A0 =A0 =A0 =A0shrink_zone(0, zone, &sc);
>> + =A0 =A0 =A0 end =3D sched_clock();
>> +
>> + =A0 =A0 =A0 if (rec) {
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 rec->nr_scanned +=3D sc.nr_scanned;
>
>
>>
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 rec->nr_freed +=3D sc.nr_reclaimed;
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 rec->elappsed +=3D end - start;
>
> elapsed?
>>
>> + =A0 =A0 =A0 }
>>
>> =A0 =A0 =A0 =A0trace_mm_vmscan_memcg_softlimit_reclaim_end(sc.nr_reclaim=
ed);
>>
>> - =A0 =A0 =A0 *nr_scanned =3D sc.nr_scanned;
>> =A0 =A0 =A0 =A0return sc.nr_reclaimed;
>> =A0}
>>
>> =A0unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_con=
t,
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 gfp_t gfp_mask,
>> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0bool noswap)
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0bool noswap,
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0struct memcg_scanrecord *rec)
>> =A0{
>> =A0 =A0 =A0 =A0struct zonelist *zonelist;
>> =A0 =A0 =A0 =A0unsigned long nr_reclaimed;
>> + =A0 =A0 =A0 unsigned long start, end;
>> =A0 =A0 =A0 =A0int nid;
>> =A0 =A0 =A0 =A0struct scan_control sc =3D {
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0.may_writepage =3D !laptop_mode,
>> @@ -2259,6 +2269,7 @@ unsigned long try_to_free_mem_cgroup_pag
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0.gfp_mask =3D sc.gfp_mask,
>> =A0 =A0 =A0 =A0};
>>
>> + =A0 =A0 =A0 start =3D sched_clock();
>> =A0 =A0 =A0 =A0/*
>> =A0 =A0 =A0 =A0 * Unlike direct reclaim via alloc_pages(), memcg's recla=
im doesn't
>> =A0 =A0 =A0 =A0 * take care of from where we get pages. So the node wher=
e we start the
>> @@ -2273,6 +2284,12 @@ unsigned long try_to_free_mem_cgroup_pag
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0sc.gfp_mask);
>>
>> =A0 =A0 =A0 =A0nr_reclaimed =3D do_try_to_free_pages(zonelist, &sc, &shr=
ink);
>> + =A0 =A0 =A0 end =3D sched_clock();
>> + =A0 =A0 =A0 if (rec) {
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 rec->nr_scanned +=3D sc.nr_scanned;
>
> sc.nr_scanned only contains the nr_scanned of last priority=A0do_try_to_f=
ree_pages(). we need to reset it to total_scanned before return. I am looki=
ng at=A0v3.0-rc3 .
>
>>
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 rec->nr_freed +=3D sc.nr_reclaimed;
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 rec->elappsed +=3D end - start;
>
> elapsed?
>>
>> + =A0 =A0 =A0 }
>>
>> =A0 =A0 =A0 =A0trace_mm_vmscan_memcg_reclaim_end(nr_reclaimed);
>>
>>
> --Ying

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