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 <[email protected]> > --- > 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). I agree your cleanup looks much better than the nested conditional. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
