From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751982AbcFUKew (ORCPT ); Tue, 21 Jun 2016 06:34:52 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:54853 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751656AbcFUKe0 (ORCPT ); Tue, 21 Jun 2016 06:34:26 -0400 Date: Tue, 21 Jun 2016 11:37:39 +0200 From: Peter Zijlstra To: "Odzioba, Lukasz" Cc: "linux-kernel@vger.kernel.org" , "x86@kernel.org" , "tglx@linutronix.de" , "mingo@redhat.com" , "hpa@zytor.com" , "ak@linux.intel.com" , "Liang, Kan" , "akpm@linux-foundation.org" , "eranian@google.com" , "acme@kernel.org" , "alexander.shishkin@linux.intel.com" , "bp@suse.de" , "Anaczkowski, Lukasz" Subject: Re: [PATCH 1/1] perf/x86/intel: Add extended event constraints for Knights Landing Message-ID: <20160621093739.GO30154@twins.programming.kicks-ass.net> References: <1465358536-21544-1-git-send-email-lukasz.odzioba@intel.com> <20160608064800.GN30154@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/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 20, 2016 at 10:26:30AM +0000, Odzioba, Lukasz wrote: > On 08.06.2016 Peter Zijlstra wrote: > > How does this work in the light of intel_alt_er() ? > > Hi Peter, > > If the constrained bit is valid on only one of the OCR MSRs (like in case of KNL), > then OCR valid mask will forbid altering it by the other MSR in intel_alt_er. Yes, that is the intent, but how is this achieved? I'm not sure I see how the patch ensure this. Also, intel_get_event_constraints() has a path where it copies the constraint, should it not also copy the new field?