From a6f5576bb195c3b7508e3e1c98d2dcf6691f96e8 Mon Sep 17 00:00:00 2001 From: Yafang Shao Date: Mon, 1 Jun 2020 21:49:32 -0700 Subject: [PATCH] mm, memcg: add workingset_restore in memory.stat There's a new workingset counter introduced in commit 1899ad18c607 ("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: Yafang Shao Signed-off-by: Andrew Morton Acked-by: Johannes Weiner Acked-by: Michal Hocko Acked-by: Chris Down Cc: Peter Zijlstra (Intel) Cc: Suren Baghdasaryan Cc: Shakeel Butt Link: http://lkml.kernel.org/r/20200504153522.11553-1-laoar.shao@gmail.com Signed-off-by: Linus Torvalds --- Documentation/admin-guide/cgroup-v2.rst | 4 ++++ mm/memcontrol.c | 2 ++ 2 files changed, 6 insertions(+) diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index bcc80269bb6a..5f12f203822e 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -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 diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 1db4b285c407..4bb922c02521 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -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));