On Tue 29-04-14 09:59:30, Tim Hockin wrote: > Here's the reason it doesn't work for us: It doesn't work. There is a "simple" solution for that. Help us to fix it. > It was something like 2 YEARS since we first wanted this, and it STILL > does not work. My recollection is that it was primarily Parallels and Google asking for the kmem accounting. The reason why I didn't fight against inclusion although the implementation at the time didn't have a proper slab shrinking implemented was that that would happen later. Well, that later hasn't happened yet and we are slowly getting there. > 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. But we cannot simply add a new interface that will have to be maintained for ever just because something else that is supposed to workaround bugs. > What I want is an API that works like rlimit but per-cgroup, rather > than per-UID. You can use an out-of-tree patchset for the time being or help to get kmem into shape. If there are principal reasons why kmem cannot be used then you better articulate them. > On Tue, Apr 29, 2014 at 9:51 AM, Frederic Weisbecker <fweisbec@xxxxxxxxx> wrote: > > On Tue, Apr 29, 2014 at 09:06:22AM -0700, Tim Hockin wrote: > >> Why the insistence that we manage something that REALLY IS a > >> first-class concept (hey, it has it's own RLIMIT) as a side effect of > >> something that doesn't quite capture what we want to achieve? > > > > It's not a side effect, the kmem task stack control was partly > > motivated to solve forkbomb issues in containers. > > > > Also in general if we can reuse existing features and code to solve > > a problem without disturbing side issues, we just do it. > > > > Now if kmem doesn't solve the issue for you for any reason, or it does > > but it brings other problems that aren't fixable in kmem itself, we can > > certainly reconsider this cgroup subsystem. But I haven't yet seen > > argument of this kind yet. > > > >> > >> Is there some specific technical reason why you think this is a bad > >> idea? > >> I would think, especially in a more unified hierarchy world, > >> that more cgroup controllers with smaller sets of responsibility would > >> make for more manageable code (within limits, obviously). > > > > Because it's core code and it adds complications and overhead in the > > fork/exit path. We just don't add new core code just for the sake of > > slightly prettier interfaces. -- Michal Hocko SUSE Labs -- 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>