Commit a6f5576b authored by Yafang Shao's avatar Yafang Shao Committed by Linus Torvalds

mm, memcg: add workingset_restore in memory.stat

There's a new workingset counter introduced in commit 1899ad18 ("mm:
workingset: tell cache transitions from workingset thrashing").  With
the help of this counter we can know the workingset is transitioning or
thrashing.  To leverage the benifit of this counter to memcg, we should
introduce it into memory.stat.  Then we could know the workingset of the
workload inside a memcg better.

Bellow is the verification of this new counter in memory.stat.  Read a
file into the memory and then read it again to make these pages be
active.  The size of this file is 1G.  (memory.max is greater than file
size) The counters in memory.stat will be

	inactive_file 0
	active_file 1073639424

	workingset_refault 0
	workingset_activate 0
	workingset_restore 0
	workingset_nodereclaim 0

Trigger the memcg reclaim by setting a lower value to memory.high, and
then some pages will be demoted into inactive list, and then some pages
in the inactive list will be evicted into the storage.

	inactive_file 498094080
	active_file 310063104

	workingset_refault 0
	workingset_activate 0
	workingset_restore 0
	workingset_nodereclaim 0

Then recover the memory.high and read the file into memory again.  As a
result of it, the transitioning will occur.  Bellow is the result of
this transitioning,

	inactive_file 498094080
	active_file 575397888

	workingset_refault 64746
	workingset_activate 64746
	workingset_restore 64746
	workingset_nodereclaim 0
Signed-off-by: default avatarYafang Shao <laoar.shao@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Acked-by: default avatarChris Down <chris@chrisdown.name>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Link: http://lkml.kernel.org/r/20200504153522.11553-1-laoar.shao@gmail.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 251af0cd
......@@ -1329,6 +1329,10 @@ PAGE_SIZE multiple when read back.
workingset_activate
Number of refaulted pages that were immediately activated
workingset_restore
Number of restored pages which have been detected as an active
workingset before they got reclaimed.
workingset_nodereclaim
Number of times a shadow node has been reclaimed
......
......@@ -1451,6 +1451,8 @@ static char *memory_stat_format(struct mem_cgroup *memcg)
memcg_page_state(memcg, WORKINGSET_REFAULT));
seq_buf_printf(&s, "workingset_activate %lu\n",
memcg_page_state(memcg, WORKINGSET_ACTIVATE));
seq_buf_printf(&s, "workingset_restore %lu\n",
memcg_page_state(memcg, WORKINGSET_RESTORE));
seq_buf_printf(&s, "workingset_nodereclaim %lu\n",
memcg_page_state(memcg, WORKINGSET_NODERECLAIM));
......
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