Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757312AbaGCHbc (ORCPT ); Thu, 3 Jul 2014 03:31:32 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:55263 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755553AbaGCHbb (ORCPT ); Thu, 3 Jul 2014 03:31:31 -0400 Date: Thu, 3 Jul 2014 09:31:07 +0200 From: Peter Zijlstra To: Jason Low Cc: torvalds@linux-foundation.org, paulmck@linux.vnet.ibm.com, mingo@kernel.org, Waiman.Long@hp.com, davidlohr@hp.com, linux-kernel@vger.kernel.org, riel@redhat.com, akpm@linux-foundation.org, hpa@zytor.com, andi@firstfloor.org, James.Bottomley@hansenpartnership.com, rostedt@goodmis.org, tim.c.chen@linux.intel.com, aswin@hp.com, scott.norton@hp.com, chegu_vinod@hp.com Subject: Re: [RFC] Cancellable MCS spinlock rework Message-ID: <20140703073107.GS19379@twins.programming.kicks-ass.net> References: <1404318070-2856-1-git-send-email-jason.low2@hp.com> <20140702162749.GP19379@twins.programming.kicks-ass.net> <1404320356.3170.12.camel@j-VirtualBox> <20140702172333.GQ19379@twins.programming.kicks-ass.net> <1404322203.3170.17.camel@j-VirtualBox> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="cxMSjUqMQBJIqbX5" Content-Disposition: inline In-Reply-To: <1404322203.3170.17.camel@j-VirtualBox> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --cxMSjUqMQBJIqbX5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Jul 02, 2014 at 10:30:03AM -0700, Jason Low wrote: > Would potentially reducing the size of the rw semaphore structure by 32 > bits (for all architectures using optimistic spinning) be a nice > benefit? Possibly, although I had a look at the mutex structure and we didn't have a hole to place it in, unlike what you found with the rwsem. --cxMSjUqMQBJIqbX5 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTtQa2AAoJEHZH4aRLwOS6+i4P/jm5zge4BYaDN0NKbCco8/E5 6SW3Fe5jHQ2awMKb6DgmvOGC6dvD+vKqIHVkzVOSTjULdqUweAtaMj6r6UYHxr8v OKQn/Kkk1gHfwoFx/zchyE5Ic6gysWP1uKl2SS/VW1oetFXkPsHDLWl29tuKBkT0 YnpVMqFKvOGzCBu1kRb7ZJoDBU4uOXmI4a9+xeurl3D8tQybxifGkmqTfZVhxc// jft6U0tAoZet+WTUmsF+cU9nXWkgs13M/DIQ/zOedKRB2s2PI2sRZspQKlgl5Dem jt2m1bCRPwgCvmPHrPDgih6tfe0gtD8sS4Yw7QieikHsGfhmGsS9+YsxgCVN2b2i 0oChKy5xHWSyvFFelz8zkfQmfjiIqpiPjcT0YmSulEGxUwcNxu60PIlJD47DTp8E bSOXYoeqjqJBc5H6jaLRIdf5ZVp1jZAFPPXLL6LT57RwT5VJ5YuPxo/EPFxDp3Se 9KEfmPOYKVWLpzTI9U6yhT7vCEVowJcj/cweAEcFiiVgwHXyVBmRmr3gFOYhtBc0 LRnR9M92yFL6XzJ9JbfZ5nWpc19OmE1Ly6G+kUrCXwzxndvFjB2ja/H+iiTzaDK+ 0QcGPDVYn/j+WYhU+UZl7HRgx7TFizYzlKLtcCQVgNfpfIBXEqJ7JcIHyqXnE8Gf 3P6p7a2GyzRvazsfog8T =fbmn -----END PGP SIGNATURE----- --cxMSjUqMQBJIqbX5-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/