From: Mike Galbraith <efault@gmx.de>
To: Peter Zijlstra <peterz@infradead.org>,
Christopher Lameter <cl@linux.com>
Cc: cmetcalf@mellanox.com, linux-kernel@vger.kernel.org,
tglx@linutronix.de, torvalds@linux-foundation.org, hpa@zytor.com,
riel@redhat.com, mingo@kernel.org, frederic@kernel.org,
kernellwp@gmail.com, paulmck@linux.vnet.ibm.com,
lcapitulino@redhat.com, linux-tip-commits@vger.kernel.org
Subject: Re: [tip:sched/core] sched/isolation: Document the isolcpus= flags
Date: Mon, 30 Oct 2017 17:56:25 +0100 [thread overview]
Message-ID: <1509382585.7399.17.camel@gmx.de> (raw)
In-Reply-To: <20171030161101.wprohopz5eg7snb4@hirez.programming.kicks-ass.net>
On Mon, 2017-10-30 at 17:11 +0100, Peter Zijlstra wrote:
> On Mon, Oct 30, 2017 at 10:48:04AM -0500, Christopher Lameter wrote:
> > On Fri, 27 Oct 2017, Peter Zijlstra wrote:
> >
> > > I _strongly_ object to this statement, isolcpus is _not_ the preferred
> > > way, cpusets are.
> > >
> > > And yes, while cpusets suffers some problems, we _should_ really fix
> > > those and not promote this piece of shit isolcpus crap.
> >
> > Well low level control at the processor level is important and this allows
> > controlling activities on a processor that is supposed to be dedicated to
> > certain activities without OS interaction.
> >
> > isolcpus is the *right* approach here because you are micromanaging the OS
> > and are putting dedicated pieces of software on each core.
>
> That is what you want, and cpusets should allow for that just fine.
>
> > A cgroup suggests that threads would be scheduled over multiple cores
> > which is *not* what you want.
>
> No, that suggestion is false. cpusets should allow you to isolate
> individual CPUs just fine.
It does. I do RT jitter testing with it regularly. If it didn't work,
my 8 socket box would let me know instantly, by completely sucking :)
-Mike
prev parent reply other threads:[~2017-10-30 16:58 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-27 2:42 [GIT PULL] Housekeeping subsystem v6 Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 01/12] housekeeping: Move housekeeping related code to its own file Frederic Weisbecker
2017-10-27 12:01 ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 02/12] watchdog: Use housekeeping_cpumask() instead of ad-hoc version Frederic Weisbecker
2017-10-27 12:02 ` [tip:sched/core] sched/isolation, " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 03/12] housekeeping: Provide a dynamic off-case to housekeeping_any_cpu() Frederic Weisbecker
2017-10-27 12:02 ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 04/12] housekeeping: Make housekeeping cpumask private Frederic Weisbecker
2017-10-27 12:03 ` [tip:sched/core] sched/isolation: Make the " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 05/12] housekeeping: Use its own static key Frederic Weisbecker
2017-10-27 12:03 ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 06/12] housekeeping: Rename is_housekeeping_cpu to housekeeping_cpu Frederic Weisbecker
2017-10-27 12:03 ` [tip:sched/core] sched/isolation: Rename is_housekeeping_cpu() to housekeeping_cpu() tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 07/12] housekeeping: Move it under its own config, independent from NO_HZ Frederic Weisbecker
2017-10-27 12:04 ` [tip:sched/core] sched/isolation: Split out new CONFIG_CPU_ISOLATION=y config from CONFIG_NO_HZ_FULL tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 08/12] housekeeping: Introduce housekeeping flags Frederic Weisbecker
2017-10-27 12:04 ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 09/12] housekeeping: Handle the nohz_full= parameter Frederic Weisbecker
2017-10-27 12:05 ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 10/12] housekeeping: Move isolcpus to housekeeping Frederic Weisbecker
2017-10-27 12:05 ` [tip:sched/core] sched/isolation: Move isolcpus= handling to the housekeeping code tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 11/12] housekeeping: Add basic isolcpus flags Frederic Weisbecker
2017-10-27 12:05 ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 12/12] housekeeping: Document " Frederic Weisbecker
2017-10-27 12:06 ` [tip:sched/core] sched/isolation: Document the isolcpus= flags tip-bot for Frederic Weisbecker
2017-10-27 13:58 ` Peter Zijlstra
2017-10-27 14:36 ` Frederic Weisbecker
2017-10-27 17:06 ` Ingo Molnar
2017-10-27 17:33 ` Frederic Weisbecker
2017-10-27 18:21 ` Ingo Molnar
2017-10-27 18:39 ` Frederic Weisbecker
2017-10-27 19:04 ` Ingo Molnar
2017-10-27 14:38 ` Mike Galbraith
2017-10-30 15:48 ` Christopher Lameter
2017-10-30 16:11 ` Peter Zijlstra
2017-10-30 16:30 ` Christopher Lameter
2017-10-30 16:58 ` Peter Zijlstra
2017-10-30 16:56 ` Mike Galbraith [this message]
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