Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751848AbaFEM7g (ORCPT ); Thu, 5 Jun 2014 08:59:36 -0400 Received: from casper.infradead.org ([85.118.1.10]:52112 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751795AbaFEM7f (ORCPT ); Thu, 5 Jun 2014 08:59:35 -0400 Date: Thu, 5 Jun 2014 14:59:29 +0200 From: Peter Zijlstra To: Stephane Eranian Cc: Matt Fleming , LKML , "mingo@elte.hu" , "ak@linux.intel.com" , Jiri Olsa , "Yan, Zheng" , Maria Dimakopoulou Subject: Re: [PATCH 9/9] perf/x86: add syfs entry to disable HT bug workaround Message-ID: <20140605125929.GH6758@twins.programming.kicks-ass.net> References: <1401917658-26065-1-git-send-email-eranian@google.com> <1401917658-26065-10-git-send-email-eranian@google.com> <20140605125022.GF6758@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Bg2esWel0ueIH/G/" Content-Disposition: inline In-Reply-To: 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 --Bg2esWel0ueIH/G/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jun 05, 2014 at 02:55:05PM +0200, Stephane Eranian wrote: > On Thu, Jun 5, 2014 at 2:50 PM, Peter Zijlstra wro= te: > > On Thu, Jun 05, 2014 at 12:16:01PM +0100, Matt Fleming wrote: > >> On 5 June 2014 11:19, Stephane Eranian wrote: > >> > How would you know that you have a uniform workload from inside > >> > the kernel? > >> > >> That's what I'm asking you ;-) > >> > >> >> Does cpu_sibling_map not give you some indication of whether HT is > >> >> enabled? I think the topology_thread_cpumask() is the topology API = for > >> >> that. But I could most definitely be wrong. Hopefully someone on the > >> >> Cc list will know. > >> >> > >> > Remember trying some of that, but when perf_event is initialized, th= ose > >> > masks are not yet setup properly. > >> > >> Oh, bummer. > > > > So we init perf very early to get nmi-watchdog up and running, but > > there's no reason you cannot register a second initcall later and flip > > the switch from it there. >=20 > and what initcall would that be? Pretty much anything !early_initcall() is ran after SMP bringup iirc. --Bg2esWel0ueIH/G/ Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTkGmxAAoJEHZH4aRLwOS6ossP/1J/YlOPFB4Iyz5koV6ouCU1 iaZmybbT7XKovIBmq1Q2I6dnlYMhpXGCCyVdgncMWNUgbTTB772AJFBpKnwaMIJd J6U8BK4fRSExXcMGXw/WIwQJfdWLoLydlv87YzFs8vSJMGbekrwyqle5KgMowJFZ 2FMw728Ljoph7+wWGbghF8NRa80bCZQ9vJXCK6+XDJKRzh1DnCOWcrvir8xujex7 rkvCiAND+s/OfMPdQiTFv67gOKixl4AeVwTpji/ouRp9O12xTCej876nWdioUXCT ppm98tkWPcMaemAbvUnMorZ6Hp8dAZJawL4QbqILFck9nnol6SrTrriGjxBcf+dB vZtkLU7xFTX6fsElPvKIo8gzyOfDZnC/oDFtAjDQMbTo9xwvATzf647f/2d3FWFe /wK946KYgF4/Jjkr0e66wO7z1o1gHhIFoBPRJnfqAOIMzONUY0G6O84rVdp0FW+1 HbQ1A7GzCq33LFFBBEOesMkJJNLDZ8XOnXgJCPk/gFCpRzOA39WdOU4zzX2MWwt3 uz3tNBiG5IwTZ4OVbe8oYvkl1A6rNTjkOnGjWZ/2Oent+EwjsIiS7pRm8obT8p/w XciesohzhFOjIss3ltvXXYbjQk/pFOPtMbfdRArNCJki6obAYp8bv8nDvAbo/jwF cD2YPvFpCTnYHB2hiiBY =RDgi -----END PGP SIGNATURE----- --Bg2esWel0ueIH/G/-- -- 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/