Messages in this thread | | | Date | Tue, 10 Jun 2008 09:14:39 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [RFC PATCH 0/5] memcg: VM overcommit accounting and handling |
| |
On Tue, 10 Jun 2008 01:32:58 +0200 Andrea Righi <righi.andrea@gmail.com> wrote:
> > Provide distinct cgroup VM overcommit accounting and handling using the memory > resource controller. >
Could you explain the benefits of this even when we have memrlimit controller ? (If unsure, see 2.6.26-rc5-mm1 and search memrlimit controller.)
And this kind of virtual-address-handling things should be implemented on memrlimit controller (means not on memory-resource-controller.). It seems this patch doesn't need to handle page_group.
Considering hierarchy, putting several kinds of features on one controller is not good, I think. Balbir, how do you think ?
Thanks, -Kame
> Patchset against latest Linus git tree. > > This patchset allows to set different per-cgroup overcommit rules and, > according to them, it's possible to return a memory allocation failure (ENOMEM) > to the applications, instead of always triggering the OOM killer via > mem_cgroup_out_of_memory() when cgroup memory limits are exceeded. > > Default overcommit settings are taken from vm.overcommit_memory and > vm.overcommit_ratio sysctl values. Child cgroups initially inherits the VM > overcommit parent's settings. > > Cgroup overcommit settings can be overridden using memory.overcommit_memory and > memory.overcommit_ratio files under the cgroup filesystem. > > For example: > > 1. Initialize a cgroup with 50MB memory limit: > # mount -t cgroup none /cgroups -o memory > # mkdir /cgroups/0 > # /bin/echo $$ > /cgroups/0/tasks > # /bin/echo 50M > /cgroups/0/memory.limit_in_bytes > > 2. Use the "never overcommit" policy with 50% ratio: > # /bin/echo 2 > /cgroups/0/memory.overcommit_memory > # /bin/echo 50 > /cgroups/0/memory.overcommit_ratio > > Assuming we have no swap space, cgroup 0 can allocate up to 25MB of virtual > memory. If that limit is exceeded all the further allocation attempts made by > userspace applications will receive a -ENOMEM. > > 4. Show committed VM statistics: > # cat /cgroups/0/memory.overcommit_as > CommitLimit: 25600 kB > Committed_AS: 9844 kB > > 5. Use "always overcommmit": > # /bin/echo 1 > /cgroups/0/memory.overcommit_memory > > This is very similar to the default memory controller configuration: overcommit > is allowed, but when there's no more available memory oom-killer is invoked. > > TODO: > - shared memory is not taken in account (i.e. files in tmpfs) > > -Andrea > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
| |