On Wed, 22 Apr 2009 21:22:54 -0400 Theodore Tso <tytso@xxxxxxx> wrote: > On Thu, Apr 23, 2009 at 09:05:35AM +0900, KAMEZAWA Hiroyuki wrote: > > So, current status is. > > > > A. memcg should support dirty_ratio for its own memory reclaim. > > in plan. > > > > B. another cgroup can be implemnted to support cgroup_dirty_limit(). > > But relationship with "A" should be discussed. > > no plan yet. > > > > C. I/O cgroup and bufferred I/O tracking system. > > Now under patch review. > > > > And this I/O throttle is mainly for "C" discussion. > > How much testing has been done in terms of whether the I/O throttling > actually works? Not just, "the kernel doesn't crash", but that where > you have one process generating a large amount of I/O load, in various > different ways, and whether the right things happens? If so, how has > this been measured? I/O control people should prove it. And they do, I think. > > I'm really concerned that given some of the ways that I/O will "leak" > out --- the via pdflush, swap writeout, etc., that without the rest of > the pieces in place, I/O throttling by itself might not prove to be > very effective. Sure, if the workload is only doing direct I/O, life > is pretty easy and it shouldn't be hard to throttle the cgroup. > It's just a problem of "what we do and what we don't, now". Andrea, Vivek, could you clarify ? As other project, I/O controller will not be 100% at first implementation. > But in the case where there is bufferred I/O, without write > throttling, it's hard to see how well the I/O controller will work in > practice. In fact, I wouldn't be that surprised if it's possible to > trigger the OOM killer....... > yes, then, memcg should have dirty_ratio handler. And, we may have to implement dirty-ratio controller. So, please don't merge memcg discussion and I/O BW throttoling. It's related to each other but different problem. Thanks, -Kame _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
