Re: [PATCH] net/skbuff: silence warnings under memory pressure

From: Petr Mladek
Date: Thu Nov 21 2019 - 04:15:24 EST


On Thu 2019-11-21 10:05:27, Sergey Senozhatsky wrote:
> On (19/11/20 17:13), Petr Mladek wrote:
> [..]
> > It is the first time that I hear about problem caused by the
> > irq_work(). But we deal with deadlocks caused by wake_up() for years.
> > It would be like replacing a lightly dripping tap with a heavily
> > dripping one.
> >
> > I see reports with WARN() from scheduler code from time to time.
> > I would get reports about silent death instead.
>
> Just curious, how many of those WARN() come under rq lock or pi_lock?
> // this is real question

I guess that all SCHED_WARN_ON() would stop working.

I am not 100% sure but I think that all WARN_ON*() in
set_task_cpu(), finish_task_switch(), migrate_tasks()
are affected.

I have seen many reports with the WARN() from
native_smp_send_reschedule() about offline CPU.

Best Regards,
Petr