From: Peter Zijlstra <peterz@infradead.org>
To: cmetcalf@mellanox.com, linux-kernel@vger.kernel.org,
tglx@linutronix.de, torvalds@linux-foundation.org, hpa@zytor.com,
riel@redhat.com, cl@linux.com, mingo@kernel.org, efault@gmx.de,
frederic@kernel.org, kernellwp@gmail.com,
paulmck@linux.vnet.ibm.com, lcapitulino@redhat.com
Cc: linux-tip-commits@vger.kernel.org
Subject: Re: [tip:sched/core] sched/isolation: Document the isolcpus= flags
Date: Fri, 27 Oct 2017 15:58:31 +0200 [thread overview]
Message-ID: <20171027135831.GZ3165@worktop.lehotels.local> (raw)
In-Reply-To: <tip-98a06af93784a6ae541e9fc6292ef26177832543@git.kernel.org>
On Fri, Oct 27, 2017 at 05:06:25AM -0700, tip-bot for Frederic Weisbecker wrote:
> + isolcpus= [KNL,SMP] Isolate a given set of CPUs from disturbance.
> + Format: [flag-list,]<cpu-list>
> +
> + Specify one or more CPUs to isolate from disturbances
> + specified in the flag list (default: domain):
> +
> + nohz
> + Disable the tick when a single task runs.
> + domain
> + Isolate from the general SMP balancing and scheduling
> + algorithms. This option is the preferred way to isolate
> + CPUs from tasks.
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.
> The alternative -- manually setting the
> + CPU mask of all tasks in the system, can cause problems
> + and suboptimal load balancer performance. You can move a
> + process onto or off an "isolated" CPU via the CPU
> + affinity syscalls or cpuset. <cpu number> begins at 0
> + and the maximum value is "number of CPUs in system - 1".
> +
> + The format of <cpu-list> is described above.
> +
next prev parent reply other threads:[~2017-10-27 13:58 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 [this message]
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
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