Re: [RFC] Shared page accounting for memory cgroup

[Balbir Singh]

* KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> [2010-01-07 18:08:00]:

> On Thu, 7 Jan 2010 17:48:14 +0900
> KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote:
> > > > "How pages are shared" doesn't show good hints. I don't hear such parameter
> > > > is used in production's resource monitoring software.
> > > > 
> > > 
> > > You mean "How many pages are shared" are not good hints, please see my
> > > justification above. With Virtualization (look at KSM for example),
> > > shared pages are going to be increasingly important part of the
> > > accounting.
> > > 
> > 
> > Considering KSM, your cuounting style is tooo bad.
> > 
> > You should add 
> > 
> >  - MEM_CGROUP_STAT_SHARED_BY_KSM
> >  - MEM_CGROUP_STAT_FOR_TMPFS/SYSV_IPC_SHMEM
> > 

No.. I am just talking about shared memory being important and shared
accounting being useful, no counters for KSM in particular (in the
memcg context).

> > counters to memcg rather than scanning. I can help tests.
> > 
> > I have no objections to have above 2 counters. It's informative.
> > 

Apart from those two, I want to provide what Pss provides today or an
approximation of it.

> > But, memory reclaim can page-out pages even if pages are shared.
> > So, "how heavy memcg is" is an independent problem from above coutners.
> > 
> 
> In other words, above counters can show
> "What role the memcg play in the system" to some extent.
> 
> But I don't express it as "heavy" ....."importance or influence of cgroup" ?
> 
> Thanks,
> -Kame
> 
> 

-- 
	Balbir
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