From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: perf uncore behavior Date: Sat, 2 May 2015 14:16:11 +0200 Message-ID: <20150502121611.GK2366@two.firstfloor.org> References: <87618blpsr.fsf@tassilo.jf.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from one.firstfloor.org ([193.170.194.197]:45423 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750920AbbEBMQN (ORCPT ); Sat, 2 May 2015 08:16:13 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: Chris Freehill Cc: Andi Kleen , linux-perf-users@vger.kernel.org On Fri, May 01, 2015 at 09:31:58PM -0500, Chris Freehill wrote: > A follow up...can you define what "sockets/nodes" means in this > context? What is the relationship between sockets/nodes and CPU's. In Linux terminology a CPU is a logical CPU thread. A socket is a physical chip. > What is the distinction? For core events, they would be the same, > right? Could you give an example of what "-a" would sum up when we are > talking about uncore events? It sums up events from all sockets > > I think my main confusion is an assumption (up to now, anyway) that > there is only one set of uncore events, for the multicore device, so > it wouldn't make sense to sum up anything. There is one set per socket (or rather chip, if you talk about an multi-chip-module) > For core events, my > understanding is that with no "-C" specified, perf sums up > the core event counts and presents this as output. For uncore, the > events are not per-core, so I'm not sure how to interpret that "sum". It's the sum of all cores on that socket. -Andi