LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: Andi Kleen <andi@firstfloor.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH] Allocate idle task for a CPU always on its local node
Date: Wed, 18 May 2016 10:28:43 +0200 (CEST)
Message-ID: <alpine.DEB.2.11.1605181028220.3851@nanos> (raw)
In-Reply-To: <1463492694-15833-1-git-send-email-andi@firstfloor.org>

On Tue, 17 May 2016, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
> 
> Linux pre-allocates the task structs of the idle tasks for all possible CPUs.
> This currently means they all end up on node 0. This also implies
> that the cache line of MWAIT, which is around the flags field in the task
> struct, are all located in node 0.
> 
> We see a noticeable performance improvement on Knights Landing CPUs when
> the cache lines used for MWAIT are located in the local nodes of the CPUs
> using them. I would expect this to give a (likely slight) improvement
> on other systems too.
> 
> The patch implements placing the idle task in the node of
> its CPUs, by passing the right target node to copy_process()
> 
> Signed-off-by: Andi Kleen <ak@linux.intel.com>

Acked-by: Thomas Gleixner <tglx@linutronix.de>

      parent reply index

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-17 13:44 Andi Kleen
2016-05-17 21:13 ` Andrew Morton
2016-05-17 21:50   ` Andi Kleen
2016-05-18  8:28 ` Thomas Gleixner [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=alpine.DEB.2.11.1605181028220.3851@nanos \
    --to=tglx@linutronix.de \
    --cc=ak@linux.intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=andi@firstfloor.org \
    --cc=linux-kernel@vger.kernel.org \
    /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

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git