Re: per-cpu statistics

[Glauber Costa <glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>]

On 03/01/2013 05:48 PM, Sha Zhengju wrote:
> Hi Glauber,
> 
> Forgive me, I'm replying not because I know the reason of current
> per-cpu implementation but that I notice you're mentioning something
> I'm also interested in. Below is the detail.
> 
> 
> I'm not sure I fully understand your points, root memcg now don't
> charge page already and only do some page stat
> accounting(CACHE/RSS/SWAP).

Can you point me to the final commits of this in the tree? I am using
the latest git mm from mhocko and it is not entirely clear for me what
are you talking about.

>  Now I'm also trying to do some
> optimization specific to the overhead of root memcg stat accounting,
> and the first attempt is posted here:
> https://lkml.org/lkml/2013/1/2/71 . But it only covered
> FILE_MAPPED/DIRTY/WRITEBACK(I've add the last two accounting in that
> patchset) and Michal Hock accepted the approach (so did Kame) and
> suggested I should handle all the stats in the same way including
> CACHE/RSS. But I do not handle things related to memcg LRU where I
> notice you have done some work.
> 
Yes, LRU is a bit tricky and it is what is keeping me from posting the
patchset I have. I haven't fully done it, but I am on my way.


> It's possible that we may take different ways to bypass root memcg
> stat accounting. The next round of the part will be sent out in
> following few days(doing some tests now), and for myself any comments
> and collaboration are welcome. (Glad to cc to you of course if you're
> also interest in it. :) )
> 

I am interested, of course. As you know, I started to work on this a
while ago and had to interrupt it for a while. I resumed it last week,
but if you managed to merge something already, I'd happy to rebase.