Re: [PATCH -mm v2 2/3] mm/oom_kill: cleanup the "kill sharing same memory" loop

From: Hillf Danton
Date: Thu Oct 08 2015 - 02:50:21 EST


>
> 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@...hat.com>
> ---
> mm/oom_kill.c | 18 +++++++++++-------
> 1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index b6b8c78..c189ee5 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -583,14 +583,18 @@ 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 (p->mm != mm)
> + continue;
> + if (same_thread_group(p, victim))
> + continue;
> + if (unlikely(p->flags & PF_KTHREAD))
> + continue;

Given the result of "grep -nr PF_KTHREAD linux-next/mm", it looks
a helper function, like current_is_kswapd(), is needed.

int task_is_kthread(struct task_struct *task)

Other than that,
Acked-by: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx>

> + if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
> + continue;
>
> - do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, true);
> - }
> + do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, true);
> + }
> rcu_read_unlock();
>
> mmput(mm);
> --
> 2.4.3
>
>


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