From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752897AbaEHOQc (ORCPT ); Thu, 8 May 2014 10:16:32 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:53195 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751472AbaEHOQa (ORCPT ); Thu, 8 May 2014 10:16:30 -0400 Date: Thu, 8 May 2014 16:16:11 +0200 From: Peter Zijlstra To: Alexander Shishkin Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Frederic Weisbecker , Mike Galbraith , Paul Mackerras , Stephane Eranian , Andi Kleen , Adrian Hunter , Matt Fleming Subject: Re: [PATCH v1 03/11] perf: Allow for multiple ring buffers per event Message-ID: <20140508141611.GB30445@twins.programming.kicks-ass.net> References: <1391683834-29868-1-git-send-email-alexander.shishkin@linux.intel.com> <1391683834-29868-4-git-send-email-alexander.shishkin@linux.intel.com> <20140507152640.GR30445@twins.programming.kicks-ass.net> <87wqdwzbxy.fsf@ashishki-desk.ger.corp.intel.com> <20140508124121.GU11096@twins.programming.kicks-ass.net> <87ha50cuab.fsf@ashishki-desk.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Lh1tzOZp3jg2TtWy" Content-Disposition: inline In-Reply-To: <87ha50cuab.fsf@ashishki-desk.ger.corp.intel.com> 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 --Lh1tzOZp3jg2TtWy Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, May 08, 2014 at 03:46:36PM +0300, Alexander Shishkin wrote: > Peter Zijlstra writes: >=20 > > On Thu, May 08, 2014 at 03:34:17PM +0300, Alexander Shishkin wrote: > >> Peter Zijlstra writes: > >>=20 > >> > So the aux_head/tail values should also be in the file space and not > >> > start at 0 again, similar for the offsets in the AUX record. > >>=20 > >> Thinking some more about it: if we keep aux_{offset,size} in userpg, > >> then it would make sense to have aux_{head,tail} run from 0 to infinity > >> similar to data_{head,tail}, especially considering that neither data_* > >> nor aux_* pointers are file offsets anyway. > > > > Yeah, this might make it easier. So then the rule is *_offset + > > *_{head,tail} is the actual file offset into the buffer. >=20 > You mean *_offset + (*_{head,tail} % *_size) ? Indeed I did..=20 --Lh1tzOZp3jg2TtWy Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTa5GqAAoJEHZH4aRLwOS6CiUQAK07jVSBGUiC9OOKF0qi0nDK 4ec+4H0ONyxZTWuVd7OAUapnefp0vugK37KOkwaunKAcOOMTSlkZtLnXFP294qYX mwQAEPxGgunuj+eXxcVXPoMonycigZHLfaxwf4MtSfcwqmbzZ1/IGJvkRbXfGviK j9poM2RD+mhxHbxXVl6l/KkOpRopekUD9vEUaj7OYfcb7MPLo1Jb0Lp1YWPFMlnM zVvWIha3DdE1hwtjDK6NWS+SGZPf4bBZE4F+1AeBIpdoI2AqaIBUPk8D/NukBzOO XSJ99iUZ1cBHR5/tCnN7vw34uYsxl5Do0YivvPhhjRDACqbxDh/rvlYy4y2Q65Na hDIB5BceGDEQyHsXS1bz1l5/c74WUcjhK6YqupZLrQHTKdA0HkGQO2cM/6u0Nbsi xTPKwe+GIxQA2DUm+gJ+p2sgcypdA6FXK83bl1HClkpZ8UK3WcBtFZHRLtbRLX9z 2JK6SyD7TSBrDtFw6rw8Vt+oIaN3jKr5U9sFJ89rC5h8FxzDD6BE/yETaTaX8C0m SULburbxC4LBG+pvskfuJSPk21XWHifpzFfm2D93k4RU+wYERnPFzOtrm3P2EICa U/og4HDd+sW6WAv2ytD2II/77WZiKPd+eEYSr0KTRocOqXSLjyF2gllqOewulPSU ixH+IqZjHoCodAewFs0Q =Dtjp -----END PGP SIGNATURE----- --Lh1tzOZp3jg2TtWy--