Messages in this thread | | | Subject | Re: [PATCH 1/6] mm, oom: do not loop over all tasks if there are no external tasks sharing mm | From | Tetsuo Handa <> | Date | Fri, 27 May 2016 01:14:35 +0900 |
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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@I-love.SAKURA.ne.jp . 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.
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