Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751591AbaFEMud (ORCPT ); Thu, 5 Jun 2014 08:50:33 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:33204 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751438AbaFEMuc (ORCPT ); Thu, 5 Jun 2014 08:50:32 -0400 Date: Thu, 5 Jun 2014 14:50:22 +0200 From: Peter Zijlstra To: Matt Fleming Cc: Stephane Eranian , 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: <20140605125022.GF6758@twins.programming.kicks-ass.net> References: <1401917658-26065-1-git-send-email-eranian@google.com> <1401917658-26065-10-git-send-email-eranian@google.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="/aVve/J9H4Wl5yVO" 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 --/aVve/J9H4Wl5yVO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable 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? >=20 > That's what I'm asking you ;-) >=20 > >> 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, those > > masks are not yet setup properly. >=20 > 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. --/aVve/J9H4Wl5yVO Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTkGeOAAoJEHZH4aRLwOS6yKYQAKb+V3GUxzShWKn2E0CcGxcX CnxoyBjRNIkLCxsI0BbtH7IKdKmhu88WOS2T1EapJ8f4wkOjBXvVXTQDR6GiVosa trzmuZLk0OWCfUawsWp9PhrvwnhJGYmDH+pz3QJkCqcoBhWScDu025+1lOQjm9Ur VbFd6RS9uhU7w6FXFOjZhm0S56hDgVVYvsjog84THlHHYG3AHS5etMbvP/BGKHoy Ho0ACsy4C5CMKr6FLAFzXEILalCohslndjq3KXEiI2kSg9Ih62dWm8VI4VSOdazw qfO+yufH8DC7RJ1hBtAJLB4/4XOqB1G8pbbpSyQtxpLdTGzu3zOPVuyBNAHzcHC0 zDrDIxJsKq2NVFS5Sm2B/BHh6qTCfc2Owv9D7sq8+CLgpUq4/k/nwODFV9riWGvP W4vgrw1AthLV8Hug/bfFsyvr13wsVtB0JDEZOL6iHoUW2JGTLFfP9riSFNRDvRix edf+GcdYIgrkJlG0XZlKF8u9SB4oH/H1bLA3F+S1ptpqTiI5hezPAizIqog4vNxI 50qpO3GWn4ulcnwL1enTEB+r7jWtzg6ICZI2zmuX1S/ZR43c1RKkUlGXJIX6mPU8 DEVgoyt+VDfoVddC/8BvGW9pC1QbM1F2ubj1erjxvPAGLA+JhSGLTzKlciEBAUwx nuLk8Q2sBGkB4SacHbXu =uJVi -----END PGP SIGNATURE----- --/aVve/J9H4Wl5yVO-- -- 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/