From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx190.postini.com [74.125.245.190]) by kanga.kvack.org (Postfix) with SMTP id 84B0B6B13F0 for ; Thu, 2 Feb 2012 06:35:08 -0500 (EST) Message-ID: <4F2A74A2.5080905@parallels.com> Date: Thu, 2 Feb 2012 15:33:54 +0400 From: Glauber Costa MIME-Version: 1.0 Subject: Re: [LSF/MM TOPIC][ATTEND] memcg topics. References: <20120201095556.812db19c.kamezawa.hiroyu@jp.fujitsu.com> <4F28FEB6.4040905@parallels.com> In-Reply-To: <4F28FEB6.4040905@parallels.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: KAMEZAWA Hiroyuki Cc: lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org, "hannes@cmpxchg.org" , Michal Hocko , "bsingharora@gmail.com" , Hugh Dickins , Ying Han , Mel Gorman On 02/01/2012 12:58 PM, Glauber Costa wrote: > On 02/01/2012 04:55 AM, KAMEZAWA Hiroyuki wrote: >> Hi, I guess we have some topics on memory cgroups. >> >> 1-4 : someone has an implemanation >> 5 : no implemenation. >> >> 1. page_cgroup diet >> memory cgroup uses 'struct page_cgroup', it was 40bytes per 4096bytes >> in past. >> Johannes removed ->page and ->lru from page_cgroup, then now, >> sizeof(page_cgroup)==16. Now, I'm working on removing ->flags to make >> sizeof(page_cgroup)==8. >> >> Then, finally, page_cgroup can be moved into struct page on 64bit >> system ? >> How 32bit system will be ? >> >> 2. memory reclaim >> Johannes, Michal and Ying, ant others, are now working on memory >> reclaim problem >> with new LRU. Under it, LRU is per-memcg-per-zone. >> Following topics are discussed now. >> >> - simplificaiton/re-implemenation of softlimit >> - isolation of workload (by softlimit) >> - when we should stop memory reclaim, especially under direct-reclaim. >> (Now, we scan all zonelist..) >> >> 3. per-memcg-lru-zone-lru-lock >> I hear Hugh Dickins have some patches and are testing it. >> It will be good to discuss this if it has Pros. and Cons or >> implemenation issue. >> >> 4. dirty ratio >> In the last year, patches were posted but not merged. I'd like to hear >> works on this area. >> >> 5. accounting other than user pages. >> Last year, tcp buffer limiting was added to "memcg". > I was about to correct you about "last year", when suddenly my mind went > "oh god, this is 2012!" > >> If someone has other plans, I'd like to hear. >> I myself don't think 'generic kernel memory limitation' is a good >> thing.... >> admins can't predict performance. >> >> Can we make accounting on dentry/inode into memcg and call >> shrink_slab() ? >> But I guess per-zone-shrink-slab() should go 1st... > > Well, I have work in progress to continue that. There are a couple of > slabs I'd like to track. I am convinced that a generic framework is a > good thing, but indeed, I am still not sure if a generic interface is. > > The advantage of keeping it unified, is that it prevents the number of > knobs from exploding. For us, this is not that much of a problem, > because there are only a couple of ones we are interested in. dcache and > inode is an example of that: when we sent out some proposals (that > didn't use memcg), some people wanted to see inode, not dcache being > tracked. We disagreed. But yet, the truth remains that only *one* of > them needs to be tracked, because they live in a close relation to each > other. So if we manage to find a couple of slabs that are key to that, > we can limit only those. > > Well, that was food for thought only. I do think this is a nice topic. > > Also, there is no serious implementation for that, as you mentioned, but > a series of patches were sent out for appreciation last year. So there > is at least a basis for starting > Forgot to add [ATTEND] to the subject. I'd like to attend to discuss that. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org