From: Dave Jones <davej@codemonkey.org.uk>
To: "Calin A. Culianu" <calin@ajvar.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: SMP Pentium4 -- PAUSE Instruction
Date: Tue, 3 Dec 2002 15:55:29 +0000 [thread overview]
Message-ID: <20021203155529.GA1622@suse.de> (raw)
In-Reply-To: <Pine.LNX.4.33L2.0212031029580.1780-100000@rtlab.med.cornell.edu>
On Tue, Dec 03, 2002 at 10:42:13AM -0500, Calin A. Culianu wrote:
>
> I as wondering -- according to Intel's docs they recommend that on a P4
> processor to use the PAUSE instruction (aka rep followed by a nop) inside
> any spin loop (such as one used in SMP spinlock code) in order to both
> improve processor performance and reduce power consumption.
> Is this instruction being used in spin-wait loops? For some reason, I am
> having a hard time figuring out whether or not it is being used. There is
> a rep_nop() in processor.h.. but I can't determine if that is being called
> for spin lock lock/unlock code.
there's also rep;nop in asm-i386/spinlock.h
See spin_lock_string()
Dave
--
| Dave Jones. http://www.codemonkey.org.uk
| SuSE Labs
next prev parent reply other threads:[~2002-12-03 15:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-12-03 15:42 SMP Pentium4 -- PAUSE Instruction Calin A. Culianu
2002-12-03 15:55 ` Dave Jones [this message]
2002-12-03 16:06 ` Arjan van de Ven
2002-12-03 17:21 ` Calin A. Culianu
-- strict thread matches above, loose matches on Subject: below --
2002-12-03 15:57 Nakajima, Jun
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=20021203155529.GA1622@suse.de \
--to=davej@codemonkey.org.uk \
--cc=calin@ajvar.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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.