On Tue, Jan 31, 2012 at 8:54 PM, KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: > On Tue, 31 Jan 2012 11:59:40 -0800 > Ying Han <yinghan@xxxxxxxxxx> wrote: > >> some topics that I would like to discuss this year: >> >> 1) we talked about soft limit redesign during last LSF, and there are >> quite a lot of efforts and changes being pushed after that. I would >> like to take this time to sync-up our efforts and also discuss some of >> the remaining issues. >> >> Discussion from last year : >> http://www.spinics.net/lists/linux-mm/msg17102.html and lots of >> changes have been made since then. >> > > Yes, it seems re-sync is required. > >> 2) memory.stat, this is the main stat file for all memcg statistics. >> are we planning to keep stuff it for something like per-memcg >> vmscan_stat, vmstat or not. >> > > Could you calrify ? Do you want to have another stat file like memory.vmstat ? I was planning to add per-memcg vmstat file at one point, but there were discussions of just extending memory.stat. I don't mind to have very long memory.stat file since my screen is now vertical anyway. Just want to sync-up our final decision for later patches. > > >> 3) root cgroup now becomes quite interesting, especially after we >> bring back the exclusive lru to root. To be more specific, root cgroup >> now is like a sink which contains pages allocated on its own, and also >> pages being re-parented. Those pages won't be reclaimed until there is >> a global pressure, and we want to see anything we can do better. >> > > I'm sorry I can't get your point. > > Do you think it's better to shrink root mem cgroup LRU even if there are > no memory pressure ? The benefit will be reduced memory reclaim latency. That is something I am thinking now. Now what we do in removing a cgroup is re-parent all the pages, and root become a sink with all the left-over pages. There is no external memory pressure to push those pages out unless global reclaim, and the machine size will look smaller and smaller on admin perspective. I am thinking to use some existing reclaim mechanism to apply pressure on those pages inside the kernel. --Ying > Or Do you think root memcg should have some soft limit and should be > reclaimed in the same schedule line as other memcgs ? The benefit will be fairness. > > or other idea ? > > Thanks, > -Kame > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>