Re: [PATCH -mmotm 0/5] memcg: per cgroup dirty limit (v6)

From: KAMEZAWA Hiroyuki
Date: Thu Mar 11 2010 - 18:56:34 EST


On Fri, 12 Mar 2010 00:27:09 +0100
Andrea Righi <arighi@xxxxxxxxxxx> wrote:

> On Thu, Mar 11, 2010 at 10:03:07AM -0500, Vivek Goyal wrote:

> > I am still setting up the system to test whether we see any speedup in
> > writeout of large files with-in a memory cgroup with small memory limits.
> > I am assuming that we are expecting a speedup because we will start
> > writeouts early and background writeouts probably are faster than direct
> > reclaim?
>
> mmh... speedup? I think with a large file write + reduced dirty limits
> you'll get a more uniform write-out (more frequent small writes),
> respect to few and less frequent large writes. The system will be more
> reactive, but I don't think you'll be able to see a speedup in the large
> write itself.
>
Ah, sorry. I misunderstood something. But it's depends on dirty_ratio param.
If
background_dirty_ratio = 5
dirty_ratio = 100
under 100M cgroup, I think background write-out will be a help.
(nonsense ? ;)

And I wonder make -j can get better number....Hmm.

Thanks,
-Kame

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