From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752365Ab1GDV5J (ORCPT ); Mon, 4 Jul 2011 17:57:09 -0400 Received: from one.firstfloor.org ([213.235.205.2]:49129 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752154Ab1GDV5H (ORCPT ); Mon, 4 Jul 2011 17:57:07 -0400 Date: Mon, 4 Jul 2011 23:57:06 +0200 From: Andi Kleen To: Lin Ming Cc: Andi Kleen , Peter Zijlstra , Ingo Molnar , Stephane Eranian , Arnaldo Carvalho de Melo , linux-kernel Subject: Re: [PATCH 1/4] perf, x86: Add Intel Nehalem/Westmere uncore pmu Message-ID: <20110704215706.GH15637@one.firstfloor.org> References: <1309421396-17438-1-git-send-email-ming.m.lin@intel.com> <1309421396-17438-2-git-send-email-ming.m.lin@intel.com> <20110630165849.GE23059@one.firstfloor.org> <1309761541.18875.40.camel@minggr.sh.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1309761541.18875.40.camel@minggr.sh.intel.com> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > There are no NMIs without sampling, so at least the comment seems bogus. > > Perhaps the code could be a bit simplified now without atomics. > > I'm not sure if uncore PMU interrupt need to be enabled for counting > only. What do you think? Only for overflow handling to accumulate into a larger counter, but it doesn't need to be an NMI for that. But it's not strictly required I would say, 44(?) bits are probably enough for near all use cases. At least initially not having one is fine I think. -Andi -- ak@linux.intel.com -- Speaking for myself only.