Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946173AbbEVNgm (ORCPT ); Fri, 22 May 2015 09:36:42 -0400 Received: from casper.infradead.org ([85.118.1.10]:49395 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757458AbbEVNgj (ORCPT ); Fri, 22 May 2015 09:36:39 -0400 Date: Fri, 22 May 2015 15:36:36 +0200 From: Peter Zijlstra To: Stephane Eranian Cc: Ingo Molnar , Vince Weaver , Jiri Olsa , LKML Subject: Re: [PATCH 02/10] perf/x86: Improve HT workaround GP counter constraint Message-ID: <20150522133636.GE3644@twins.programming.kicks-ass.net> References: <20150522112146.GZ3644@twins.programming.kicks-ass.net> <20150522112800.GO18673@twins.programming.kicks-ass.net> <20150522125344.GA3644@twins.programming.kicks-ass.net> <20150522125908.GB3644@twins.programming.kicks-ass.net> <20150522132534.GD3644@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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 Content-Length: 861 Lines: 19 On Fri, May 22, 2015 at 06:29:47AM -0700, Stephane Eranian wrote: > On Fri, May 22, 2015 at 6:25 AM, Peter Zijlstra wrote: > > On Fri, May 22, 2015 at 06:07:00AM -0700, Stephane Eranian wrote: > >> > >> One other thing I noticed is that the --n_excl needs to be protected by the > >> excl_cntrs->lock in put_excl_constraints(). > > > > Nah, its strictly per cpu. > > No. the excl_cntrs struct is pointed to by cpuc but it is shared between the > sibling HT. Otherwise this would not work! n_excl is per cpuc, see the trickery with has_exclusive vs exclusive_present on how I avoid the lock. -- 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/