From: Frederic Weisbecker <fweisbec@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Chris Metcalf <cmetcalf@mellanox.com>,
Thomas Gleixner <tglx@linutronix.de>,
Luiz Capitulino <lcapitulino@redhat.com>,
Christoph Lameter <cl@linux.com>,
"Paul E . McKenney" <paulmck@linux.vnet.ibm.com>,
Ingo Molnar <mingo@kernel.org>, Mike Galbraith <efault@gmx.de>,
Rik van Riel <riel@redhat.com>, Wanpeng Li <kernellwp@gmail.com>
Subject: Re: [RFC PATCH 12/12] housekeeping: Reimplement isolcpus on housekeeping
Date: Mon, 28 Aug 2017 15:23:06 +0200 [thread overview]
Message-ID: <20170828132302.GA32618@lerouge> (raw)
In-Reply-To: <20170828100957.jcjhh77ylxvsyisy@hirez.programming.kicks-ass.net>
On Mon, Aug 28, 2017 at 12:09:57PM +0200, Peter Zijlstra wrote:
> On Wed, Aug 23, 2017 at 03:51:11AM +0200, Frederic Weisbecker wrote:
> > We want to centralize the isolation features on the housekeeping
> > subsystem and scheduler isolation is a significant part of it.
> >
> > While at it, this is a proposition for a reimplementation of isolcpus=
> > that doesn't involve scheduler domain isolation. Therefore this
> > brings a behaviour change: all user tasks inherit init/1 affinity which
> > avoid the isolcpus= range. But if a task later overrides its affinity
> > which turns out to intersect an isolated CPU, load balancing may occur
> > on it.
> >
> > OTOH such a reimplementation that doesn't shortcut scheduler internals
> > makes a better candidate for an interface extension to cpuset.
>
> Not sure we can do this. It'll break users that rely on the no
> scheduling thing, that's a well documented part of isolcpus.
That was my worry :-s That NULL domain was probably a design mistake and
I fear we now have to maintain it.
next prev parent reply other threads:[~2017-08-28 13:23 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-23 1:50 [RFC 00/12] Introduce housekeeping subsystem v2 Frederic Weisbecker
2017-08-23 1:51 ` [RFC PATCH 01/12] housekeeping: Move housekeeping related code to its own file Frederic Weisbecker
2017-08-31 20:16 ` Rik van Riel
2017-08-31 22:58 ` Frederic Weisbecker
2017-08-23 1:51 ` [RFC PATCH 02/12] watchdog: Use housekeeping_cpumask() instead of ad-hoc version Frederic Weisbecker
2017-08-23 1:51 ` [RFC PATCH 03/12] housekeeping: Provide a dynamic off-case to housekeeping_any_cpu() Frederic Weisbecker
2017-08-23 1:51 ` [RFC PATCH 04/12] housekeeping: Make housekeeping cpumask private Frederic Weisbecker
2017-08-23 1:51 ` [RFC PATCH 05/12] housekeeping: Use its own static key Frederic Weisbecker
2017-08-23 1:51 ` [RFC PATCH 06/12] housekeeping: Rename is_housekeeping_cpu to housekeeping_cpu Frederic Weisbecker
2017-08-23 1:51 ` [RFC PATCH 07/12] housekeeping: Move it under own config, independant from NO_HZ Frederic Weisbecker
2017-08-23 1:51 ` [RFC PATCH 08/12] housekeeping: Introduce housekeeping flags Frederic Weisbecker
2017-08-23 1:51 ` [RFC PATCH 09/12] workqueue: Affine unbound workqueues to housekeeping cpumask Frederic Weisbecker
2017-08-23 1:51 ` [RFC PATCH 10/12] housekeeping: Affine unbound kthreads Frederic Weisbecker
2017-08-23 1:51 ` [RFC PATCH 11/12] housekeeping: Handle nohz_full= parameter Frederic Weisbecker
2017-08-23 1:51 ` [RFC PATCH 12/12] housekeeping: Reimplement isolcpus on housekeeping Frederic Weisbecker
2017-08-23 14:55 ` Christopher Lameter
2017-08-24 13:19 ` Frederic Weisbecker
2017-08-28 10:10 ` Peter Zijlstra
2017-08-28 15:38 ` Christopher Lameter
2017-08-28 10:09 ` Peter Zijlstra
2017-08-28 13:23 ` Frederic Weisbecker [this message]
2017-08-28 13:31 ` Peter Zijlstra
2017-08-28 15:27 ` Frederic Weisbecker
2017-08-28 16:24 ` Peter Zijlstra
2017-08-28 16:53 ` Christopher Lameter
2017-08-28 17:33 ` Frederic Weisbecker
2017-08-31 18:53 ` Thomas Gleixner
2017-08-31 23:00 ` Frederic Weisbecker
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