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From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Tejun Heo <htejun@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] sched/kthread: Complain loudly when others violate our flags
Date: Mon, 03 Oct 2011 12:20:38 +0200	[thread overview]
Message-ID: <1317637238.20367.6.camel@twins> (raw)
In-Reply-To: <20111003011506.GE31799@mtj.dyndns.org>

On Sun, 2011-10-02 at 18:15 -0700, Tejun Heo wrote:
> Anyways, I don't think I'm gonna take this one.  There are some
> attractions to the approach - ie. making the users determine whether
> they need strict affinity or not and mandating those users to shut
> down properly from cpu down callbacks and if we're doing this from the
> scratch, this probably would be a sane choice.  But we already have
> tons of users and relatively well tested code.  I don't see compelling
> reasons to perturb that at this point.
> 
So wtf am I going to do with people who want PF_THREAD_BOUND to actually
do what it means? Put a warning in the scheduler code to flag all
violations and let you sort out the workqueue fallout?

I didn't write this change for fun, I actually need to get
PF_THREAD_BOUND back to sanity, this change alone isn't enough, but it
gets rid of the worst abuse. This isn't frivolous perturbation.

> Also, on a quick glance, the change is breaking non-reentrance
> guarantee.
> 
How so? Afaict it does exactly what the trustee thread used to do, or is
it is related to the NON_AFFINE moving the worklets around?

  reply	other threads:[~2011-10-03 10:21 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-27 21:17 [PATCH] sched/kthread: Complain loudly when others violate our flags Steven Rostedt
2011-09-28  0:22 ` Thomas Gleixner
2011-09-30  3:48 ` Tejun Heo
2011-09-30  4:05   ` Steven Rostedt
2011-09-30  4:14     ` Tejun Heo
2011-09-30  8:34       ` Peter Zijlstra
2011-09-30  8:55         ` Tejun Heo
2011-09-30  9:04           ` Peter Zijlstra
2011-10-03  1:15             ` Tejun Heo
2011-10-03 10:20               ` Peter Zijlstra [this message]
2011-10-07  1:40                 ` Tejun Heo
2011-10-03 10:33               ` Peter Zijlstra
2011-10-03 13:43                 ` Thomas Gleixner
2011-10-03 10:50               ` Peter Zijlstra
2011-09-30  9:23       ` Peter Zijlstra
2011-09-30  9:29       ` Peter Zijlstra
2011-09-30  9:27   ` Peter Zijlstra
2011-10-03  1:22     ` Tejun Heo
2011-09-30  3:55 ` Tejun Heo
2011-09-30  4:08   ` Steven Rostedt
2011-09-30  4:28     ` Tejun Heo

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