linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Arjan van de Ven <arjan@infradead.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
	linux-kernel@vger.kernel.org, x86@kernel.org,
	arjanvandeven@gmail.com, Thomas Gleixner <tglx@linutronix.de>
Subject: Re: x86: clean up smpboot.c's use of udelay+schedule
Date: Tue, 31 Jan 2012 05:43:51 -0800	[thread overview]
Message-ID: <20120131054351.0a9f35ed@infradead.org> (raw)
In-Reply-To: <20120131125331.GE4408@elte.hu>

On Tue, 31 Jan 2012 13:53:32 +0100
Ingo Molnar <mingo@elte.hu> wrote:
> 
> Wanna give a short TODO list to anyone wanting to work on that?

the biggest thing that needs to happen is splitting the hardware
specific part ("bring the chip up") and the OS specific part of
cpu_up() ("get the cpu into our accounting/awareness").

the former does not need the hotplug or any other big lock (just a state
machine), the later needs the hotplug lock for obvious reasons.
The former is the part that takes a long time (> 100msec for a first
cpu in a package, > 30msec for second and later), the later is quick.



-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org

  parent reply	other threads:[~2012-01-31 13:42 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-31  4:53 x86: clean up smpboot.c's use of udelay+schedule Arjan van de Ven
2012-01-31 12:43 ` Ingo Molnar
2012-01-31 12:47   ` Peter Zijlstra
2012-01-31 12:53     ` Ingo Molnar
2012-01-31 13:01       ` Peter Zijlstra
2012-02-02  0:33         ` Paul E. McKenney
2012-02-02  8:03           ` Srivatsa S. Bhat
2012-02-02 15:23             ` Paul E. McKenney
2012-02-03 17:32               ` Paul E. McKenney
2012-01-31 13:43       ` Arjan van de Ven [this message]
2012-01-31 13:32   ` Arjan van de Ven
2012-01-31 14:30     ` Ingo Molnar

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=20120131054351.0a9f35ed@infradead.org \
    --to=arjan@infradead.org \
    --cc=a.p.zijlstra@chello.nl \
    --cc=arjanvandeven@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=tglx@linutronix.de \
    --cc=x86@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
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).