From: Christopher Lameter <cl@linux.com>
To: Peter Zijlstra <peterz@infradead.org>
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, efault@gmx.de,
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 10:48:04 -0500 (CDT) [thread overview]
Message-ID: <alpine.DEB.2.20.1710301045160.970@nuc-kabylake> (raw)
In-Reply-To: <20171027135831.GZ3165@worktop.lehotels.local>
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.
A cgroup suggests that threads would be scheduled over multiple cores
which is *not* what you want. cgroup has to do something with containers
etc which is inherently more noisy and needed if you want to do different
things with your processing resources.
next prev parent reply other threads:[~2017-10-30 15:48 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 [this message]
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
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