On Mon, Aug 2, 2021 at 1:08 PM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote: > > On Mon, Aug 2, 2021 at 1:05 PM Shakeel Butt <shakeelb@xxxxxxxxxx> wrote: > > > > On Mon, Aug 2, 2021 at 12:54 PM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote: > > > > > > On Mon, Jul 26, 2021 at 6:44 AM Shakeel Butt <shakeelb@xxxxxxxxxx> wrote: > > > > > > > > On Mon, Jul 26, 2021 at 12:27 AM Michal Hocko <mhocko@xxxxxxxx> wrote: > > > > > > > > > [...] > > > > > > > > > > Is process_mrelease on all of them really necessary? I thought that the > > > > > primary reason for the call is to guarantee a forward progress in cases > > > > > where the userspace OOM victim cannot die on SIGKILL. That should be > > > > > more an exception than a normal case, no? > > > > > > > > > > > > > I am thinking of using this API in this way: On user-defined OOM > > > > condition, kill a job/cgroup and unconditionally reap all of its > > > > processes. Keep monitoring the situation and if it does not improve go > > > > for another kill and reap. > > > > > > > > I can add additional logic in between kill and reap to see if reap is > > > > necessary but unconditionally reaping is more simple. > > > > > > > > > > > > > > > An alternative would be to have a cgroup specific interface for > > > > > > reaping similar to cgroup.kill. > > > > > > > > > > Could you elaborate? > > > > > > > > > > > > > I mentioned this in [1] where I was thinking if it makes sense to > > > > overload cgroup.kill to also add the SIGKILLed processes in > > > > oom_reaper_list. The downside would be that there will be one thread > > > > doing the reaping and the syscall approach allows userspace to reap in > > > > multiple threads. I think for now, I would go with whatever Suren is > > > > proposing and we can always add more stuff if need arises. > > > > > > > > [1] https://lore.kernel.org/containers/CALvZod4jsb6bFzTOS4ZRAJGAzBru0oWanAhezToprjACfGm+ew@xxxxxxxxxxxxxx/ > > > > > > Hi Folks, > > > So far I don't think there was any request for further changes. > > > Anything else you would want me to address or are we in a good shape > > > wrt this feature? > > > If so, would people who had a chance to review this patchset be > > > willing to endorse it with their Reviewed-by or Acked-by? > > > > I think with Michal's suggestion to use a killable mmap lock, at least > > I am good with the patch. > > Ah, yes. Thanks for pointing this out! I'll replace mmap_read_lock() > with mmap_read_lock_killable(). Will post an updated version later > today. Posted the next version at https://lore.kernel.org/patchwork/patch/1471403/
