From: Nick Piggin <npiggin@suse.de>
To: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <andi@firstfloor.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: queued spinlock code and results
Date: Wed, 11 Jul 2007 06:51:12 +0200 [thread overview]
Message-ID: <20070711045111.GA1563@wotan.suse.de> (raw)
In-Reply-To: <Pine.LNX.4.64.0707101924030.7089@schroedinger.engr.sgi.com>
On Tue, Jul 10, 2007 at 07:26:10PM -0700, Christoph Lameter wrote:
> On Wed, 11 Jul 2007, Nick Piggin wrote:
>
> > BTW. some advanced congestion algorithms like HBO may find these ticket
> > locks useful because you can see immediately how many CPUs are contending
> > the lock, and spinners know how many CPUs are in front of them. That info
> > could be fed into the spin backoff scheme.
>
> That would mean having to keep a lot of status information for a spinlock.
> Gets pretty complicated.
Did you look at the implementation? It takes 2 bytes on x86 and is almost
the same code size and speed as the existing locks.
> The RT tree already converts spinlocks to sleeping locks? If we want to be
> that complicated then maybe going with one sophisticated lock type for all
> would be the solution.
I don't want to convert spinlocks to sleeping locks though.
next prev parent reply other threads:[~2007-07-11 4:51 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-08 4:32 queued spinlock code and results Nick Piggin
2007-07-08 11:18 ` Andi Kleen
2007-07-08 10:40 ` Nick Piggin
2007-07-08 16:49 ` Linus Torvalds
2007-07-10 20:52 ` Christoph Lameter
2007-07-11 2:06 ` Nick Piggin
2007-07-11 2:26 ` Christoph Lameter
2007-07-11 4:51 ` Nick Piggin [this message]
2007-07-09 19:01 ` Davide Libenzi
2007-07-09 19:16 ` Davide Libenzi
2007-07-09 19:26 ` Linus Torvalds
2007-07-09 19:47 ` Davide Libenzi
2007-07-09 19:55 ` Linus Torvalds
2007-07-09 20:08 ` Linus Torvalds
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