Marian Marinov wrote: > On 05/07/2014 08:15 PM, Dwight Engen wrote: > >On Tue, 06 May 2014 14:40:55 +0300 > >Marian Marinov <mm@xxxxxxxx> wrote: > > > >>On 04/23/2014 03:49 PM, Dwight Engen wrote: > >>>On Wed, 23 Apr 2014 09:07:28 +0300 > >>>Marian Marinov <mm@xxxxxxxx> wrote: > >>> > >>>>On 04/22/2014 11:05 PM, Richard Davies wrote: > >>>>>Dwight Engen wrote: > >>>>>>Richard Davies wrote: > >>>>>>>Vladimir Davydov wrote: > >>>>>>>>In short, kmem limiting for memory cgroups is currently broken. > >>>>>>>>Do not use it. We are working on making it usable though. > >>>>>... > >>>>>>>What is the best mechanism available today, until kmem limits > >>>>>>>mature? > >>>>>>> > >>>>>>>RLIMIT_NPROC exists but is per-user, not per-container. > >>>>>>> > >>>>>>>Perhaps there is an up-to-date task counter patchset or similar? > >>>>>> > >>>>>>I updated Frederic's task counter patches and included Max > >>>>>>Kellermann's fork limiter here: > >>>>>> > >>>>>>http://thread.gmane.org/gmane.linux.kernel.containers/27212 > >>>>>> > >>>>>>I can send you a more recent patchset (against 3.13.10) if you > >>>>>>would find it useful. > >>>>> > >>>>>Yes please, I would be interested in that. Ideally even against > >>>>>3.14.1 if you have that too. > >>>> > >>>>Dwight, do you have these patches in any public repo? > >>>> > >>>>I would like to test them also. > >>> > >>>Hi Marian, I put the patches against 3.13.11 and 3.14.1 up at: > >>> > >>>git://github.com/dwengen/linux.git cpuacct-task-limit-3.13 > >>>git://github.com/dwengen/linux.git cpuacct-task-limit-3.14 > >>> > >>Guys I tested the patches with 3.12.16. However I see a problem with > >>them. > >> > >>Trying to set the limit to a cgroup which already have processes in > >>it does not work: > > > >This is a similar check/limitation to the one for kmem in memcg, and is > >done here to keep the res_counters consistent and from going negative. > >It could probably be relaxed slightly by using res_counter_set_limit() > >instead, but you would still need to initially set a limit before > >adding tasks to the group. > > I have removed the check entirely and still receive the EBUSY... I > just don't understand what is returning it. If you have any > pointers, I would be happy to take a look. > > I'll look at set_limit(), thanks for pointing that one. > > What I'm proposing is the following checks: > > if (val > RES_COUNTER_MAX || val < 0) > return -EBUSY; > if (val != 0 && val <= cgroup_task_count(cgrp)) > return -EBUSY; > > res_counter_write_u64(&ca->task_limit, type, val); > > This way we ensure that val is within the limits > 0 and < > RES_COUNTER_MAX. And also allow only values of 0 or greater then the > current task count. I have also noticed that I can't change many different cgroup limits while there are tasks running in the cgroup - not just cpuacct.task_limit, but also kmem and even normal memory.limit_in_bytes I would like to be able to change all of these limits, as long as the new limit is greater than the actual current use. Could a method like this be used for all of the others too? Richard. > >>[root@sp2 lxc]# echo 50 > cpuacct.task_limit > >>-bash: echo: write error: Device or resource busy > >>[root@sp2 lxc]# echo 0 > cpuacct.task_limit > >>-bash: echo: write error: Device or resource busy > >>[root@sp2 lxc]# > >> > >>I have even tried to remove this check: > >>+ if (cgroup_task_count(cgrp) > >>|| !list_empty(&cgrp->children)) > >>+ return -EBUSY; > >>But still give me 'Device or resource busy'. > >> > >>Any pointers of why is this happening ? > >> > >>Marian -- 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>