From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754083Ab2JaGbJ (ORCPT ); Wed, 31 Oct 2012 02:31:09 -0400 Received: from e38.co.us.ibm.com ([32.97.110.159]:39956 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751786Ab2JaGbF (ORCPT ); Wed, 31 Oct 2012 02:31:05 -0400 Date: Tue, 30 Oct 2012 23:31:33 -0700 From: Sukadev Bhattiprolu To: peterz@infradead.org, robert.richter@amd.org, acme@redhat.com Cc: linux-kernel@vger.kernel.org, sukadev@linux.vnet.ibm.com Subject: [PATCH] perf: x86 filter_events() - use hw event id ? Message-ID: <20121031063133.GA12037@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Operating-System: Linux 2.0.32 on an i486 User-Agent: Mutt/1.5.20 (2009-06-14) X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12103106-5518-0000-0000-000008DAAC0E Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>From c3b53a5733fdea35807f4513255bca05e3aee5c5 Mon Sep 17 00:00:00 2001 From: Sukadev Bhattiprolu Date: Tue, 30 Oct 2012 23:05:05 -0700 Subject: [PATCH] perf: x86 filter_events() - use hw event id ? The ->event_map() operation expects to index through the _hardware event id_. But filter_events() function is calling ->event_map() with a loop index i. Suppose a processor does not implement say PERF_COUNT_HW_BUS_CYCLES (6), but implements, PERF_COUNT_HW_STALLED_CYCLES_FRONTEND (7). ->event_map() for "bus cycles" returns 0, we push the "stalled-cycles-frontend" event up by one in the events_attr[]. The index of "stalled-cycles-frontend" in the events_attr[] is 6 which is different from its hardware event id 7. The next and subsequent calls to ->event_map() will use this index in the modified events_attr[] table. All subsequent event ids appear unimplemented because they continue to check the same index (6 in this case). Should'nt we be checking the hardware event id instead ? I have not tested this on x86 - only on my port of the sysfs events to Power. --- arch/x86/kernel/cpu/perf_event.c | 11 ++++++++++- 1 files changed, 10 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 0a55ab2..ae88512 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -1325,12 +1325,21 @@ struct perf_pmu_events_attr { * Remove all undefined events (x86_pmu.event_map(id) == 0) * out of events_attr attributes. */ +#define PMU_ATTR(a) container_of((a), struct perf_pmu_events_attr, attr) +#define DEV_ATTR(a) container_of((a), struct device_attribute, attr) + static void __init filter_events(struct attribute **attrs) { int i, j; + struct perf_pmu_events_attr *pmu_attr; + struct device_attribute *dev_attr; + for (i = 0; attrs[i]; i++) { - if (x86_pmu.event_map(i)) + dev_attr = DEV_ATTR(attrs[i]); + pmu_attr = PMU_ATTR(dev_attr); + + if (x86_pmu.event_map(pmu_attr->id)) continue; for (j = i; attrs[j]; j++) -- 1.7.1