Messages in this thread | | | Date | Wed, 30 Sep 2015 15:49:43 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH -mm 2/3] mm/oom_kill: cleanup the "kill sharing same memory" |
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On 09/29, David Rientjes wrote: > > On Tue, 29 Sep 2015, Oleg Nesterov wrote: > > > Purely cosmetic, but the complex "if" condition looks annoying to me. > > Especially because it is not consistent with OOM_SCORE_ADJ_MIN check > > which adds another if/continue. > > > > Signed-off-by: Oleg Nesterov <oleg@redhat.com> > > --- > > mm/oom_kill.c | 22 +++++++++++++--------- > > 1 file changed, 13 insertions(+), 9 deletions(-) > > > > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > > index 0d581c6..8e7bed2 100644 > > --- a/mm/oom_kill.c > > +++ b/mm/oom_kill.c > > @@ -583,16 +583,20 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p, > > * pending fatal signal. > > */ > > rcu_read_lock(); > > - for_each_process(p) > > - if (p->mm == mm && !same_thread_group(p, victim) && > > - !(p->flags & PF_KTHREAD)) { > > - if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) > > - continue; > > + for_each_process(p) { > > + if (unlikely(p->flags & PF_KTHREAD)) > > + continue; > > + if (same_thread_group(p, victim)) > > + continue; > > + if (p->mm != mm) > > + continue; > > This ordering is a little weird to me, I think we would eliminate the > majority of processes by checking for p->mm != mm first. There are > certainly pathological cases where that can be defeated, but in practice > it seems to happen more often than not. > > Unless you object, I think the ordering should be p->mm != mm, > same_thread_group(), unlikely(PF_KTHREAD) as it originally was (thanks for > adding the unlikely).
OK, agreed, will send v2.
Oleg.
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