2017-11-20 20:39 GMT+08:00 Michal Hocko <mhocko@xxxxxxxxxx>: > On Mon 20-11-17 20:16:15, Yafang Shao wrote: >> 2017-11-20 20:04 GMT+08:00 Michal Hocko <mhocko@xxxxxxxxxx>: >> > On Fri 17-11-17 09:49:54, Shakeel Butt wrote: >> >> On Fri, Nov 17, 2017 at 9:41 AM, Yafang Shao <laoar.shao@xxxxxxxxx> wrote: >> > [...] >> >> > Of couse that is the best way. >> >> > But we can not ensue all applications will do it. >> >> > That's why I introduce a proper defalut value for them. >> >> > >> >> >> >> I think we disagree on the how to get proper default value. Unless you >> >> can restrict that all the memory allocated for a tmpfs mount will be >> >> charged to a specific memcg, you should not just pick limit of the >> >> memcg of the process mounting the tmpfs to set the default of tmpfs >> >> mount. If you can restrict tmpfs charging to a specific memcg then the >> >> limit of that memcg should be used to set the default of the tmpfs >> >> mount. However this feature is not present in the upstream kernel at >> >> the moment (We have this feature in our local kernel and I am planning >> >> to upstream that). >> > >> > I think the whole problem is that containers pretend to be independent >> > while they share a non-reclaimable resource. Fix this and you will not >> > have a problem. I am afraid that the only real fix is to make tmpfs >> > private per container instance and that is something you can easily >> > achieve in the userspace. >> > >> >> Agree with you. > > I suspect you misunderstood... > >> Introduce tmpfs stat in memory cgroup, something like >> memory.tmpfs.limit >> memory.tmpfs.usage >> >> IMHO this is the best solution. > > No, you misunderstood. I do not think that we want to split tmpfs out of > the regular limit. We used to have something like that for user vs. > kernel memory accounting in v1 and that turned to be not working well. > understood. That really doesn't work well. > What you really want to do is to make a private mount per container to > ensure that the resource is really _yours_ > -- That is what I'm doing it currently. Then setting the default size depends on the container memory limit works well. Thanks Yafang -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
