Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754873Ab0AUI7q (ORCPT ); Thu, 21 Jan 2010 03:59:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754816Ab0AUI7o (ORCPT ); Thu, 21 Jan 2010 03:59:44 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:57719 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754698Ab0AUI7f (ORCPT ); Thu, 21 Jan 2010 03:59:35 -0500 Subject: Re: [RFC] perf_events: support for uncore a.k.a. nest units From: Peter Zijlstra To: eranian@gmail.com Cc: Corey Ashford , LKML , Ingo Molnar , Andi Kleen , Paul Mackerras , Frederic Weisbecker , Xiao Guangrong , Dan Terpstra , Philip Mucci , Maynard Johnson , Carl Love In-Reply-To: <7c86c4471001210047v5907f9d8ncecc1f5441afab3a@mail.gmail.com> References: <4B560ACD.4040206@linux.vnet.ibm.com> <1263994448.4283.1052.camel@laptop> <1264023204.4283.1124.camel@laptop> <7c86c4471001210047v5907f9d8ncecc1f5441afab3a@mail.gmail.com> Content-Type: text/plain; charset="UTF-8" Date: Thu, 21 Jan 2010 09:59:04 +0100 Message-ID: <1264064344.4283.1136.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1220 Lines: 24 On Thu, 2010-01-21 at 09:47 +0100, stephane eranian wrote: > I don't think that is correct. You can be using the uncore PMU on Nehalem > without any core PMU event. The only thing to realize is that uncore PMU > shares the same interrupt vector as core PMU. You need to configure which > core the uncore is going to interrupt on. This is done via a bitmask, so you > can interrupt more than one core at a time. Several strategies are possible. Ah, sharing the IRQ line is no problem. But from reading I got the impression you need to configure an Offcore counter. See 30.6.2.1: • EN_PMI_COREn (bit n, n = 0, 3 if four cores are present): When set, processor core n is programmed to receive an interrupt signal from any interrupt enabled uncore counter. PMI delivery due to an uncore counter overflow is enabled by setting IA32_DEBUG_CTL.Offcore_PMI_EN to 1. Which seems to indicate a link with the off-core response thing. However I would be very glad to be wrong :-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/