Messages in this thread | | | Date | Thu, 11 Mar 2010 10:17:26 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [PATCH -mmotm 0/5] memcg: per cgroup dirty limit (v6) |
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On Thu, 11 Mar 2010 09:39:13 +0900 KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote: > > The performance overhead is not so huge in both solutions, but the impact on > > performance is even more reduced using a complicated solution... > > > > Maybe we can go ahead with the simplest implementation for now and start to > > think to an alternative implementation of the page_cgroup locking and > > charge/uncharge of pages. > > > > maybe. But in this 2 years, one of our biggest concerns was the performance. > So, we do something complex in memcg. But complex-locking is , yes, complex. > Hmm..I don't want to bet we can fix locking scheme without something complex. > But overall patch set seems good (to me.) And dirty_ratio and dirty_background_ratio will give us much benefit (of performance) than we lose by small overheads.
IIUC, this series affects trgger for background-write-out.
Could you show some score which dirty_ratio give us benefit in the cases of
- copying a file in a memcg which hits limit ex) copying a 100M file in 120MB limit. etc..
- kernel make performance in limited memcg. ex) making a kernel in 100MB limit (too large ?) etc....(when an application does many write and hits memcg's limit.)
But, please get enough ack for changes in generic codes of dirty_ratio.
Thank you for your work.
Regards, -Kame
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