On Tue, Jul 17, 2018 at 09:49:46PM +0200, Michal Hocko wrote: > On Tue 17-07-18 10:38:45, Roman Gushchin wrote: > [...] > > Let me show my proposal on examples. Let's say we have the following hierarchy, > > and the biggest process (or the process with highest oom_score_adj) is in D. > > > > / > > | > > A > > | > > B > > / \ > > C D > > > > Let's look at different examples and intended behavior: > > 1) system-wide OOM > > - default settings: the biggest process is killed > > - D/memory.group_oom=1: all processes in D are killed > > - A/memory.group_oom=1: all processes in A are killed > > 2) memcg oom in B > > - default settings: the biggest process is killed > > - A/memory.group_oom=1: the biggest process is killed > > Huh? Why would you even consider A here when the oom is below it? > /me confused I do not. This is exactly a counter-example: A's memory.group_oom is not considered at all in this case, because A is above ooming cgroup. > > > - B/memory.group_oom=1: all processes in B are killed > > - B/memory.group_oom=0 && > > - D/memory.group_oom=1: all processes in D are killed > > What about? > - B/memory.group_oom=1 && D/memory.group_oom=0 All tasks in B are killed. Group_oom set to 1 means that the workload can't tolerate killing of a random process, so in this case it's better to guarantee consistency for B. Thanks!
