From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753062Ab2DBWQ4 (ORCPT ); Mon, 2 Apr 2012 18:16:56 -0400 Received: from merlin.infradead.org ([205.233.59.134]:44847 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751686Ab2DBWQz (ORCPT ); Mon, 2 Apr 2012 18:16:55 -0400 Subject: Re: [PATCH 2/5] perf: generic intel uncore support From: Peter Zijlstra To: "Yan, Zheng" Cc: mingo@elte.hu, andi@firstfloor.org, eranian@google.com, linux-kernel@vger.kernel.org, ming.m.lin@intel.com In-Reply-To: <4F77C75B.4060105@intel.com> References: <1332916998-10628-1-git-send-email-zheng.z.yan@intel.com> <1332916998-10628-3-git-send-email-zheng.z.yan@intel.com> <1333163902.2960.63.camel@laptop> <4F77C75B.4060105@intel.com> Content-Type: text/plain; charset="UTF-8" Date: Tue, 03 Apr 2012 00:16:48 +0200 Message-ID: <1333405008.2960.84.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2012-04-01 at 11:11 +0800, Yan, Zheng wrote: > > So what's up with all this box->lock business.. why does that lock > > exist? > > If user doesn't provide the "-C x" option to the perf tool, multiple cpus > will try adding/deleting events at the same time. Right, however: > > Aside from all this, there's still the problem that you don't place all > > events for a particular phys_id onto a single cpu. It doesn't matter > > which cpu in that package it is, but all events should go to the same. > > > > This means that on unplug of that cpu, you have to migrate all these > > events etc.. > > Any hints how to do this. I'm afraid it requires big changes to perf core. Yes it'll need some core changes, but I don't think I'll be too bad, I'll try and write up something soonish..