On Wed, Apr 30, 2014 at 09:12:20AM -0400, Daniel J Walsh wrote: > > On 04/29/2014 05:44 PM, Frederic Weisbecker wrote: > > On Tue, Apr 29, 2014 at 09:59:30AM -0700, Tim Hockin wrote: > >> Here's the reason it doesn't work for us: It doesn't work. It was > >> something like 2 YEARS since we first wanted this, and it STILL does > >> not work. > > When I was working on the task counter cgroup subsystem 2 years > > ago, the patches were actually pushed back by google people, in favour > > of task stack kmem cgroup subsystem. > > > > The reason was that expressing the forkbomb issue in terms of > > number of tasks as a resource is awkward and that the real resource > > in the game comes from kernel memory exhaustion due to task stack being > > allocated over and over, swap ping-pong and stuffs... > > > > And that was a pretty good argument. I still agree with that. Especially > > since that could solve others people issues at the same time. kmem > > cgroup has a quite large domain of application. > > > >> You're postponing a pretty simple request indefinitely in > >> favor of a much more complex feature, which still doesn't really give > >> me what I want. What I want is an API that works like rlimit but > >> per-cgroup, rather than per-UID. > > The request is simple but I don't think that adding the task counter > > cgroup subsystem is simpler than extending the kmem code to apply limits > > to only task stack. Especially in terms of maintainance. > > > > Also you guys have very good mm kernel developers who are already > > familiar with this. > I would look at this from a Usability point of view. It is a lot easier > to understand number of processes then the mount of KMEM those processes > will need. Setting something like > ProcessLimit=1000 in a systemd unit file is easy to explain. Yeah that's a fair point. > Now if systemd has the ability to translate this into something that makes > sense in terms of kmem cgroup, then my argument goes away. Yeah if we keep the kmem direction, this can be a place where we do the mapping. Now I just hope the amount of stack memory allocated doesn't differ too much per arch. -- 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>