From: William Lee Irwin III <wli@holomorphy.com>
To: Nick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Ravikiran G Thirumalai <kiran@scalex86.org>
Subject: Re: [rfc][patch] queued spinlocks (i386)
Date: Fri, 23 Mar 2007 04:02:24 -0700 [thread overview]
Message-ID: <20070323110224.GP2986@holomorphy.com> (raw)
In-Reply-To: <20070323103243.GE11577@wotan.suse.de>
On Fri, Mar 23, 2007 at 11:04:18AM +0100, Ingo Molnar wrote:
>> isnt this patented by MS? (which might not worry you SuSE/Novell guys,
>> but it might be a worry for the rest of the world ;-)
On Fri, Mar 23, 2007 at 11:32:44AM +0100, Nick Piggin wrote:
> Hmm, it looks like they have implemented a system where the spinning
> cpu sleeps on a per-CPU variable rather than the lock itself, and
> the releasing cpu writes to that variable to wake it. They do this
> so that spinners don't continually perform exclusive->shared
> transitions on the lock cacheline. They call these things queued
> spinlocks. They don't seem to be very patent worthy either, but
> maybe it is what you're thinking of?
Those exclusive-to-shared transitions are among the cacheline transfers
typically accounted to the algorithms in their complexity analyses.
-- wli
next prev parent reply other threads:[~2007-03-23 11:02 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-23 8:59 [rfc][patch] queued spinlocks (i386) Nick Piggin
2007-03-23 9:40 ` Eric Dumazet
2007-03-23 9:59 ` Nick Piggin
2007-03-23 19:27 ` Ravikiran G Thirumalai
2007-03-23 10:04 ` Ingo Molnar
2007-03-23 10:10 ` Nick Piggin
2007-03-23 16:48 ` Parag Warudkar
2007-03-23 18:15 ` Davide Libenzi
2007-03-23 10:32 ` Nick Piggin
2007-03-23 10:40 ` Eric Dumazet
2007-03-23 11:02 ` William Lee Irwin III [this message]
2007-03-24 15:55 ` Nikita Danilov
2007-03-24 17:29 ` Ingo Molnar
2007-03-24 18:49 ` Nikita Danilov
2007-03-28 6:43 ` Nick Piggin
2007-03-28 19:26 ` Davide Libenzi
2007-03-28 22:00 ` Davide Libenzi
2007-03-29 1:36 ` Nick Piggin
2007-03-29 7:16 ` Nick Piggin
2007-03-30 0:27 ` Davide Libenzi
2007-03-30 1:59 ` Nick Piggin
2007-03-30 2:43 ` Davide Libenzi
2007-03-29 1:24 ` Nick Piggin
2007-03-24 21:41 ` Andrew Morton
2007-03-28 6:56 ` Nick Piggin
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=20070323110224.GP2986@holomorphy.com \
--to=wli@holomorphy.com \
--cc=kiran@scalex86.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=npiggin@suse.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 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.