On Fri 27-05-16 01:14:35, Tetsuo Handa wrote: > Michal Hocko wrote: > > On Fri 27-05-16 00:25:23, Tetsuo Handa wrote: > > > I think that remembering whether this mm might be shared between > > > multiple thread groups at clone() time (i.e. whether > > > clone(CLONE_VM without CLONE_SIGHAND) was ever requested on this mm) > > > is safe (given that that thread already got SIGKILL or is exiting). > > > > I was already playing with that idea but I didn't want to add anything > > to the fork path which is really hot. This patch is not really needed > > for the rest. It just felt like a nice optimization. I do not think it > > is worth deeper changes in the fast paths. > > "[PATCH 6/6] mm, oom: fortify task_will_free_mem" depends on [PATCH 1/6]. > You will need to update [PATCH 6/6]. > > It seems to me that [PATCH 6/6] resembles > http://lkml.kernel.org/r/201605250005.GHH26082.JOtQOSLMFFOFVH@xxxxxxxxxxxxxxxxxxx . > I think we will be happy if we can speed up mm_is_reapable() test using > "whether this mm might be shared between multiple thread groups" flag. > I don't think updating such flag at clone() is too heavy operation to add. It is still an operation which is not needed for 99% of situations. So if we do not need it for correctness then I do not think this is worth bothering. -- 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>