From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755484AbaENOx5 (ORCPT ); Wed, 14 May 2014 10:53:57 -0400 Received: from casper.infradead.org ([85.118.1.10]:50087 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752156AbaENOxz (ORCPT ); Wed, 14 May 2014 10:53:55 -0400 Date: Wed, 14 May 2014 16:53:45 +0200 From: Peter Zijlstra To: Davidlohr Bueso Cc: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, tim.c.chen@linux.intel.com, peter@hurleysoftware.com, jason.low2@hp.com, riel@redhat.com, alex.shi@linaro.org, paulmck@linux.vnet.ibm.com, akpm@linux-foundation.org, tglx@linutronix.de, walken@google.com, linux-tip-commits@vger.kernel.org Subject: Re: [tip:locking/core] rwsem: Add comments to explain the meaning of the rwsem's count field Message-ID: <20140514145345.GN30445@twins.programming.kicks-ass.net> References: <1399060437.2970.146.camel@schen9-DESK> <1400077624.9356.6.camel@buesod1.americas.hpqcorp.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="jNp2UUAAd0DeWbgM" Content-Disposition: inline In-Reply-To: <1400077624.9356.6.camel@buesod1.americas.hpqcorp.net> 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 --jNp2UUAAd0DeWbgM Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, May 14, 2014 at 07:27:04AM -0700, Davidlohr Bueso wrote: > On Mon, 2014-05-05 at 01:46 -0700, tip-bot for Tim Chen wrote: > > Commit-ID: 3cf2f34e1a3d4d5ff209d087925cf950e52f4805 > > Gitweb: http://git.kernel.org/tip/3cf2f34e1a3d4d5ff209d087925cf950e= 52f4805 > > Author: Tim Chen > > AuthorDate: Fri, 2 May 2014 12:53:57 -0700 > > Committer: Ingo Molnar > > CommitDate: Sun, 4 May 2014 20:34:26 +0200 > >=20 > > rwsem: Add comments to explain the meaning of the rwsem's count field > >=20 > > It took me quite a while to understand how rwsem's count field > > mainifested itself in different scenarios. > >=20 > > Add comments to provide a quick reference to the the rwsem's count > > field for each scenario where readers and writers are contending > > for the lock. > >=20 > > Hopefully it will be useful for future maintenance of the code and > > for people to get up to speed on how the logic in the code works. >=20 > sigh, after this commit, the opt spin patch no longer applies, I'm > rebasing and send out v5. No worries, fixed it already. --jNp2UUAAd0DeWbgM Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTc4N5AAoJEHZH4aRLwOS6QF0P/iuP0jnsPvbMHRjdS6XWJM2F iB+/fTFZVTPOI/B5NUO1CwOJGcmLKGZ5a9CvbozGdnmtQW3SPPHLAcbYVrBPSoRT ov0bCh+HvPl/vN5/c8RnDX4drwoIojuvjt+OmaMvy0vZy9ZCJC3tNtNnx7jUg7cq aGemHWePXzZKnuA2ge74yjUGTiPgXXANGl3TnV85sJoPB6dzLjt2wx0PFbS+icvz iPJTRKnTu+ys5c4BCAp111aRt32FtAKT/AuqcaiOjufijgb55e4ato2qkHCeVE9q irKHcbrGSehy7DKToOxzQcbdDZgZURYJlFt9lrKLUO+3zGhCv+sjJxv1M4IcnODH 75mYV8+J9jPiQhW+eZVOu9uI9GTIx8mSaBSd06MBndzBk3LOFvRJlWRyAujm3Bp3 MKqVQlyLmjhilBncnxM1kWL0rQefy6hVbHB/5OCP6Ma33dnsiYFkMQSEJVMte1vY O3HcLtsfYzySUZwm2MNKblsynubhgQI8WEMB3qAJrkx1/Bwzy6vw0Q8rnRr3Z4Xm 3ChL1/VDyyA8/daJoj9LQiRLPt/OMUwgJIIYwVkYQvC5EWO4XLJ5+ggclPPE9wqw pK6vSzvcjBgfPMfJbzEXqIImdxNvRvHmEX832klDPeYP1TMFYyajbPbfBupMyU4q b3QDKWxklz3E3R4Kt/Dt =9/dP -----END PGP SIGNATURE----- --jNp2UUAAd0DeWbgM--