Hi Andrew,

After several rounds of review, parts of the memcg page accounting
patchset is ready (leaving memcg dirty page accounting under more
review):

  1/8 memcg: remove MEMCG_NR_FILE_MAPPED
  2/8 ceph: vfs __set_page_dirty_nobuffers interface instead of doing
it inside filesystem
  3/8 memcg: check for proper lock held in mem_cgroup_update_page_stat
  5/8 memcg: add per cgroup writeback pages accounting
  8/8 memcg: Document cgroup dirty/writeback memory statistics

But the 2/8 ceph one has been improved again and will be merged in
ceph tree, so only the other 4 patches need to be added to -mm tree.
I've moved the 5/8 writeback one up the stack and updated the 8/8 to
only document writeback changes. Could you please merge them earlier?
I'll post these updated patches soon. :)

Thank you!


---------- Forwarded message ----------
From: Michal Hocko <redacted>
Date: Sun, Aug 4, 2013 at 6:08 PM
Subject: Re: [PATCH V5 5/8] memcg: add per cgroup writeback pages accounting
To: Sha Zhengju <redacted>
Cc: "linux-fsdevel@vger.kernel.org" <redacted>,
"linux-mm@kvack.org" [off-list ref], Cgroups
[off-list ref], KAMEZAWA Hiroyuki
[off-list ref], Glauber Costa [off-list ref],
Greg Thelen [off-list ref], Wu Fengguang
[off-list ref], Andrew Morton [off-list ref],
Sha Zhengju [off-list ref]


On Sat 03-08-13 17:25:01, Sha Zhengju wrote:

On Thu, Aug 1, 2013 at 10:53 PM, Michal Hocko [off-list ref] wrote:

quoted

On Thu 01-08-13 19:54:11, Sha Zhengju wrote:

quoted

From: Sha Zhengju <redacted>

Similar to dirty page, we add per cgroup writeback pages accounting. The lock
rule still is:
        mem_cgroup_begin_update_page_stat()
        modify page WRITEBACK stat
        mem_cgroup_update_page_stat()
        mem_cgroup_end_update_page_stat()

There're two writeback interfaces to modify: test_{clear/set}_page_writeback().
Lock order:
      --> memcg->move_lock
        --> mapping->tree_lock

Signed-off-by: Sha Zhengju <redacted>

Looks good to me. Maybe I would suggest moving this patch up the stack
so that it might get merged earlier as it is simpler than dirty pages
accounting. Unless you insist on having the full series merged at once.

I think the following three patches can be merged earlier:
      1/8 memcg: remove MEMCG_NR_FILE_MAPPED
      3/8 memcg: check for proper lock held in mem_cgroup_update_page_stat
      5/8 memcg: add per cgroup writeback pages accounting

Do I need to resent them again for you or they're enough?

This is a question for Andrew. I would go with them as they are.

One more word, since dirty accounting is essential to future memcg
dirty page throttling and it is not an optional feature now, I suspect
whether we can merge the following two as well and leave the overhead
optimization a separate series.  :p

I wouldn't hurry it. We need numbers for serious testing to see the
overhead. It is still just a small step towards dirty throttling.

      4/5 memcg: add per cgroup dirty pages accounting
      8/8 memcg: Document cgroup dirty/writeback memory statistics

The 2/8 ceph one still need more improvement, I'll separate it next version.

quoted

Acked-by: Michal Hocko <redacted>

Thank you.

[...]
--
Michal Hocko
SUSE Labs


-- 
Thanks,
Sha