On Mon, Jul 01, 2013 at 01:01:01PM -0500, Serge Hallyn wrote: > Quoting Aaron Staley (aaron@xxxxxxxxxxx): > > This is better explained here: > > http://serverfault.com/questions/516074/why-are-applications-in-a-memory-limited-lxc-container-writing-large-files-to-di > > (The > > highest-voted answer believes this to be a kernel bug.) > > Hi, > > in irc it has been suggested that indeed the kernel should be slowing > down new page creates while waiting for old page cache entries to be > written out to disk, rather than ooming. > > With a 3.0.27-1-ac100 kernel, doing dd if=/dev/zero of=xxx bs=1M > count=100 is immediately killed. In contrast, doing the same from a > 3.0.8 kernel did the right thing for me. But I did reproduce your > experiment below on ec2 with the same result. > > So, cc:ing linux-mm in the hopes someone can tell us whether this > is expected behavior, known mis-behavior, or an unknown bug. It's a known issue that was fixed/improved in e62e384 'memcg: prevent OOM with too many dirty pages', included in 3.6+. > > Summary: I have set up a system where I am using LXC to create multiple > > virtualized containers on my system with limited resources. Unfortunately, I'm > > running into a troublesome scenario where the OOM killer is hard killing > > processes in my LXC container when I write a file with size exceeding the > > memory limitation (set to 300MB). There appears to be some issue with the > > file buffering respecting the containers memory limit. > > > > > > Reproducing: > > > > /done on a c1.xlarge instance running on Amazon EC2 > > > > Create 6 empty lxc containers (in my case I did lxc-create -n testcon -t > > ubuntu -- -r precise) > > > > Modify the configuration of each container to set lxc.cgroup.memory. > > limit_in_bytes = 300M > > > > Within each container run: > > dd if=/dev/zero of=test2 bs=100k count=5010 > > parallel > > > > This will with high probability activate the OOM (as seen in demsg); often > > the dd processes themselves will be killed. > > > > This has been verified to have problems on: > > Linux 3.8.0-25-generic #37-Ubuntu SMP and Linux ip-10-8-139-98 > > 3.2.0-29-virtual #46-Ubuntu SMP Fri Jul 27 17:23:50 UTC 2012 x86_64 x86_64 > > x86_64 GNU/Linux > > > > Please let me know your thoughts. > > > > Regards, > > Aaron Staley > > _______________________________________________ > > Containers mailing list > > Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx > > https://lists.linuxfoundation.org/mailman/listinfo/containers > > -- > 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/ . > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers
