Re: [PATCH tip/core/rcu 01/22] sched: Make non-production PREEMPT cond_resched() help Tasks RCU

From: Paul E. McKenney
Date: Mon Apr 23 2018 - 15:11:32 EST


On Mon, Apr 23, 2018 at 08:47:07AM -0700, Paul E. McKenney wrote:
> On Mon, Apr 23, 2018 at 10:35:29AM -0400, Steven Rostedt wrote:
> > On Mon, 23 Apr 2018 16:10:38 +0200
> > Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> >
> > > > http://lkml.kernel.org/r/20180227153646.GD3777@xxxxxxxxxxxxxxxxxx
> > >
> > > That thread using cond_resched_task_rcu_qs() seems like a _lot_ better
> > > than having cond_resched() semantics change depending on random
> > > !scheduler config parameters.
> >
> > Yeah, I agree. Not sure why Paul didn't push it. Maybe because I never
> > replied to that final email and he forgot?
> >
> > Paul?
>
> Yeah, I have been a bit event-driven of late. So the thought is to keep
> cond_resched() as-is and use cond_resched_task_rcu_qs(), that is after
> the rename, for the stress tests instead of the current cond_resched().
> Or did I lose the thread?

Actually, I already use cond_resched_tasks_rcu_qs() in
benchmark_event_kthread(), so all I need to do is drop this commit.

Which I have done, thanks everyone for the review!

Thanx, Paul