linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Frederic Weisbecker <frederic@kernel.org>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: linux-kernel@vger.kernel.org,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Chris Friesen <chris.friesen@windriver.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Jim Somerville <Jim.Somerville@windriver.com>,
	Christoph Lameter <cl@linux.com>
Subject: Re: [patch 0/4] affine kernel threads to nohz_full= cpumask (v4)
Date: Mon, 20 Apr 2020 18:02:46 +0200	[thread overview]
Message-ID: <20200420160245.GA10024@lenoir> (raw)
In-Reply-To: <20200401121018.104226700@redhat.com>

On Wed, Apr 01, 2020 at 09:10:18AM -0300, Marcelo Tosatti wrote:
> This is a kernel enhancement that configures the cpu affinity of kernel
> threads via kernel boot option nohz_full=.
> 
> When this option is specified, the cpumask is immediately applied upon
> thread launch. This does not affect kernel threads that specify cpu
> and node.
> 
> This allows CPU isolation (that is not allowing certain threads
> to execute on certain CPUs) without using the isolcpus=domain parameter,
> making it possible to enable load balancing on such CPUs
> during runtime (see kernel-parameters.txt).
> 
> Note-1: this is based off on Wind River's patch at
> https://github.com/starlingx-staging/stx-integ/blob/master/kernel/kernel-std/centos/patches/affine-compute-kernel-threads.patch
> 
> Difference being that this patch is limited to modifying
> kernel thread cpumask: Behaviour of other threads can
> be controlled via cgroups or sched_setaffinity.
> 
> Note-2: Wind River's patch was based off Christoph Lameter's patch at
> https://lwn.net/Articles/565932/ with the only difference being
> the kernel parameter changed from kthread to kthread_cpus.
> 
> v2: use isolcpus= subcommand (Thomas Gleixner)
> 
> v3: s/MontaVista/Wind River/ on changelog (Chris Friesen)
>     documentation updates                 (Chris Friesen)
>     undeprecate isolcpus                  (Chris Friesen)
>     general cleanups                      (Frederic Weisbecker)
>     separate cpu_possible_mask kthread
>     mask change                           (Frederic Weisbecker)
> 
> v4: disable idle load balancing for nohz_full=
>     use nohz_full= option for kthread isolation (Frederic Weisbecker)
> 


Thanks for the patches. I'm applying them, I may add a few details
to the changelogs and stuff.

      parent reply	other threads:[~2020-04-20 16:02 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-01 12:10 [patch 0/4] affine kernel threads to nohz_full= cpumask (v4) Marcelo Tosatti
2020-04-01 12:10 ` [patch 1/4] kthread: switch to cpu_possible_mask Marcelo Tosatti
2020-04-01 12:10 ` [patch 2/4] isolation: set HK_FLAG_SCHED on nohz_full CPUs Marcelo Tosatti
2020-04-01 12:10 ` [patch 3/4] isolcpus: affine kernel threads to housekeeping cpus Marcelo Tosatti
2020-04-01 22:32   ` Randy Dunlap
2020-04-03 10:37   ` [patch 3/4 v2] " Marcelo Tosatti
2020-04-01 12:10 ` [patch 4/4] isolcpus: undeprecate on documentation Marcelo Tosatti
2020-04-20 16:02 ` Frederic Weisbecker [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200420160245.GA10024@lenoir \
    --to=frederic@kernel.org \
    --cc=Jim.Somerville@windriver.com \
    --cc=akpm@linux-foundation.org \
    --cc=chris.friesen@windriver.com \
    --cc=cl@linux.com \
    --cc=fweisbec@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mtosatti@redhat.com \
    --cc=peterz@infradead.org \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).