On Mon, May 9, 2011 at 4:49 PM, KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: > On Mon, 9 May 2011 14:49:17 +0200 > Michal Hocko <mhocko@xxxxxxx> wrote: > >> On Mon 09-05-11 12:18:17, Johannes Weiner wrote: >> > On Mon, May 09, 2011 at 04:10:47PM +0900, KAMEZAWA Hiroyuki wrote: >> [...] >> > What I am wondering, though: we already have a limit to push back >> > memcgs when we need memory, the soft limit. The 'need for memory' is >> > currently defined as global memory pressure, which we know may be too >> > late. The problem is not having no limit, the problem is that we want >> > to control the time of when this limit is enforced. So instead of >> > adding another limit, could we instead add a knob like >> > >> > memory.force_async_soft_reclaim >> > >> > that asynchroneously pushes back to the soft limit instead of having >> > another, separate limit to configure? >> > > Hmm, ok to me. I don't have problem of the actual tunable for this, but I don't think setting the soft_limit as the target for per-memcg background reclaim is feasible in some cases. That will be too aggressive than it is necessary. > >> Sound much better than a separate watermark to me. I am just wondering >> how we would implement soft unlimited groups with background reclaim. >> Btw. is anybody relying on such configuration? To me it sounds like >> something should be either limited or unlimited and making it half of >> both is hacky. > > I don't think of soft-unlimited configuration. I don't want to handle it > in some automatic way. > > Anyway, I'll add > - _automatic_ background reclaim against the limit of memory, which works > regarless of softlimit. I agree to have the background reclaim first w/ automatic watermark setting and then adding a configurable knob on top of that. So I assume we keep the same concept of high/low_wmarks, and what's the suggested default value for the watermarks? The default value now is equal to hard_limit which disables he per-memcg background reclaim. Under the new scheme which we remove the configurable tunable, we need to set it internally based on the hard_limit. --Ying > - An interface for force softlimit. > > Thanks, > -Kame > > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx 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