From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754311AbaIHJqP (ORCPT ); Mon, 8 Sep 2014 05:46:15 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:38136 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754137AbaIHJqJ (ORCPT ); Mon, 8 Sep 2014 05:46:09 -0400 Date: Mon, 8 Sep 2014 11:45:48 +0200 From: Peter Zijlstra To: Jiri Olsa Cc: Jiri Olsa , linux-kernel@vger.kernel.org, Andi Kleen , Arnaldo Carvalho de Melo , Corey Ashford , David Ahern , Frederic Weisbecker , Ingo Molnar , "Jen-Cheng(Tommy) Huang" , Namhyung Kim , Paul Mackerras , Stephane Eranian Subject: Re: [PATCH 1/9] perf: Remove redundant parent context check from context_equiv Message-ID: <20140908094548.GA6758@twins.programming.kicks-ass.net> References: <1408977943-16594-1-git-send-email-jolsa@kernel.org> <1408977943-16594-2-git-send-email-jolsa@kernel.org> <20140902105036.GH5806@worktop.ger.corp.intel.com> <20140908094348.GB1172@krava.brq.redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="6W/vd+xQRxZFP9Eu" Content-Disposition: inline In-Reply-To: <20140908094348.GB1172@krava.brq.redhat.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 --6W/vd+xQRxZFP9Eu Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Sep 08, 2014 at 11:43:48AM +0200, Jiri Olsa wrote: > On Tue, Sep 02, 2014 at 12:50:36PM +0200, Peter Zijlstra wrote: > > On Mon, Aug 25, 2014 at 04:45:35PM +0200, Jiri Olsa wrote: > > > As described in commit: > > > 1f9a7268c67f perf: Do not allow optimized switch for non-cloned eve= nts > > > we dont allow optimized switch for non cloned contexts. > > >=20 > > > There's no need now to check if one of the context is parent > > > of the other in context_equiv function. > > >=20 > >=20 > > OK, so talk to me about that patch; it looks like you're slowly > > reverting: 5a3126d4fe7c ("perf: Fix the perf context switch > > optimization"). > >=20 > > So what exactly is the problem? I'm still jet-lagged and not seeing it. >=20 > the problem is, that we cannot allow non-cloned context > to be part of the optimized switch for reasons explained > in commit 1f9a7268c67f The thing is; I don't understand those reasons. That commit log doesn't explain. --6W/vd+xQRxZFP9Eu Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJUDXrMAAoJEHZH4aRLwOS6ftoQAJxXWWRxn/GVyeCHJAWd2dBU ms9V3qAWvuGKMC6zukFUrMIe9g2NbEQIdGlka/Iqzm32Mg1KRHaoqoMhBicxdfC6 bc6Geg0lGgVP4/0pKv2Hj2+iEtuvU4kDsRy5fGukeXCDtrSR5F7sYrsOxpXrDqJd DvIEPHaZl5beUE0vMhO9AbIBP2X7M/34bA72/yLJxKjdMFDtjwSTaWsRY08BWZc7 4z1T4UTG/Ecv7CQIWBtwiKlNmQMVCCLctxfOBOqNDs7YJt3PX6LschMJ2P5Uo+ex CkSQQjGIgWOFulWVqsOkiFrtymovfsfSSrhho0/ltBFpaDSuYjQhas2BM6ZvvWiw HpRB2wYz9WvyywMNbN4f5rFgL9gpL3D/3GV2NaCIQGHTIob2jf3tPuSnrxshITDT Ha7PsuhbG1D8tSPxosH52BbzdjlqPvtRB3vWdHzrYKHxmFGvfcMKTSoF8epxE2Fo rUp3aWhbhFZ/EXLnCE2OSDGsyFvVVOv7m98LQvkgAE/vlehmxwnj5GD3iWQDkBBa QQI4EJvaXCD2zMkt6IoKog2ivprafYd8Vxa+xWRDA4Gb3fSBJfnw0IidVkxwsmhp zTEjHjo4nsTfzS7P05/bhkIMkeX0g5Obcu2ut1RVHIeSjfFmhY6HI9ZFgfD5pDMW 4kpd4798NiUCDsppm5sM =ecoM -----END PGP SIGNATURE----- --6W/vd+xQRxZFP9Eu--