From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 11 Jul 2013 16:58:08 +1000 From: Michael Ellerman To: Vince Weaver Subject: Re: [PATCH v2 2/2] perf tools: Make Power7 events available for perf Message-ID: <20130711065807.GA26495@concordia> References: <1372170933-4538-3-git-send-email-runzhen@linux.vnet.ibm.com> <20130704125218.GA21134@concordia> <20130704125700.GM18898@dyad.programming.kicks-ass.net> <20130709012952.GA7185@concordia> <20130709081434.GI25631@dyad.programming.kicks-ass.net> <20130710030926.GD7491@concordia> <20130710083435.GA24070@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, Stephane Eranian , Vince Weaver , acme@redhat.com, paulus@samba.org, xiaoguangrong@linux.vnet.ibm.com, Runzhen Wang , sukadev@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, Ingo Molnar List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Jul 11, 2013 at 12:42:31AM -0400, Vince Weaver wrote: > On Wed, 10 Jul 2013, Ingo Molnar wrote: > > > Exactly - PMUs enumerated in /sys should be self-identifying, it's a > > hardware topology after all ... > > > > Anytime userspace is forced to look into /proc, or into weird places in > > /sys it's a FAIL really. > > well on x86 you have to look at /proc/cpuinfo to get the > vendor/family/model number. Should we add some specifier under sys? > It's probably too late though as all userspace event libs will have > to look at /proc/cpuinfo anyway to be backwards compatible. If it's a new library implementing a new feature then no I don't think it needs to be backward compatible. It's just a choice the library makes as to what extent it depends on new kernel features. cheers