From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756385Ab3HRUfB (ORCPT ); Sun, 18 Aug 2013 16:35:01 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:43647 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756326Ab3HRUe5 (ORCPT ); Sun, 18 Aug 2013 16:34:57 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, John McCalpin , Vince Weaver , Peter Zijlstra , Arnaldo Carvalho de Melo , Paul Mackerras , Ingo Molnar , zheng.z.yan@intel.com Subject: [ 01/45] perf/x86: Fix intel QPI uncore event definitions Date: Sun, 18 Aug 2013 13:35:50 -0700 Message-Id: <20130818203621.098555466@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.3.825.g36032ce.dirty In-Reply-To: <20130818203620.996166594@linuxfoundation.org> References: <20130818203620.996166594@linuxfoundation.org> User-Agent: quilt/0.60-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vince Weaver commit c9601247f8f3fdc18aed7ed7e490e8dfcd07f122 upstream. John McCalpin reports that the "drs_data" and "ncb_data" QPI uncore events are missing the "extra bit" and always return zero values unless the bit is properly set. More details from him: According to the Xeon E5-2600 Product Family Uncore Performance Monitoring Guide, Table 2-94, about 1/2 of the QPI Link Layer events (including the ones that "perf" calls "drs_data" and "ncb_data") require that the "extra bit" be set. This was confusing for a while -- a note at the bottom of page 94 says that the "extra bit" is bit 16 of the control register. Unfortunately, Table 2-86 clearly says that bit 16 is reserved and must be zero. Looking around a bit, I found that bit 21 appears to be the correct "extra bit", and further investigation shows that "perf" actually agrees with me: [root@c560-003.stampede]# cat /sys/bus/event_source/devices/uncore_qpi_0/format/event config:0-7,21 So the command # perf -e "uncore_qpi_0/event=drs_data/" Is the same as # perf -e "uncore_qpi_0/event=0x02,umask=0x08/" While it should be # perf -e "uncore_qpi_0/event=0x102,umask=0x08/" I confirmed that this last version gives results that agree with the amount of data that I expected the STREAM benchmark to move across the QPI link in the second (cross-chip) test of the original script. Reported-by: John McCalpin Signed-off-by: Vince Weaver Cc: zheng.z.yan@intel.com Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1308021037280.26119@vincent-weaver-1.um.maine.edu Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/perf_event_intel_uncore.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c @@ -314,8 +314,8 @@ static struct uncore_event_desc snbep_un static struct uncore_event_desc snbep_uncore_qpi_events[] = { INTEL_UNCORE_EVENT_DESC(clockticks, "event=0x14"), INTEL_UNCORE_EVENT_DESC(txl_flits_active, "event=0x00,umask=0x06"), - INTEL_UNCORE_EVENT_DESC(drs_data, "event=0x02,umask=0x08"), - INTEL_UNCORE_EVENT_DESC(ncb_data, "event=0x03,umask=0x04"), + INTEL_UNCORE_EVENT_DESC(drs_data, "event=0x102,umask=0x08"), + INTEL_UNCORE_EVENT_DESC(ncb_data, "event=0x103,umask=0x04"), { /* end: all zeroes */ }, };