Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759846Ab2JaAfZ (ORCPT ); Tue, 30 Oct 2012 20:35:25 -0400 Received: from mga02.intel.com ([134.134.136.20]:21748 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759650Ab2JaAek (ORCPT ); Tue, 30 Oct 2012 20:34:40 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.80,683,1344236400"; d="scan'208";a="234886231" From: Andi Kleen To: linux-kernel@vger.kernel.org Cc: acme@redhat.com, peterz@infradead.org, jolsa@redhat.com, eranian@google.com, mingo@kernel.org, namhyung@kernel.org, Andi Kleen Subject: [PATCH 30/32] perf, x86: Add a Haswell precise instructions event v2 Date: Tue, 30 Oct 2012 17:34:21 -0700 Message-Id: <1351643663-23828-31-git-send-email-andi@firstfloor.org> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <1351643663-23828-1-git-send-email-andi@firstfloor.org> References: <1351643663-23828-1-git-send-email-andi@firstfloor.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2095 Lines: 50 From: Andi Kleen Add a instructions-p event alias that uses the PDIR randomized instruction retirement event. This is useful to avoid some systematic sampling shadow problems. Normally PEBS sampling has a systematic shadow. With PDIR enabled the hardware adds some randomization that statistically avoids this problem. In this sense, it's more precise over a whole sampling interval, but an individual sample can be less precise. But since we sample overall it's a more precise event. This could be used before using the explicit event code syntax, but it's easier and more user friendly to use with an "instructions-p" alias. I expect this will eventually become a common use case. Right now for Haswell, will add to Ivy Bridge later too. v2: Use new sysfs infrastructure Signed-off-by: Andi Kleen --- arch/x86/kernel/cpu/perf_event_intel.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index e8fb4e2..d177d88 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -2033,6 +2033,7 @@ EVENT_ATTR_STR(cycles-t, cycles_t, "event=0x3c,intx=1"); EVENT_ATTR_STR(cycles-ct, cycles_ct, "event=0x3c,intx=1,intx_cp=1"); EVENT_ATTR_STR(instructions-t, instructions_t, "event=0xc0,intx=1"); EVENT_ATTR_STR(instructions-ct,instructions_ct,"event=0xc0,intx=1,intx_cp=1"); +EVENT_ATTR_STR(instructions-p, instructions_p, "event=0xc0,umask=0x01,precise=2"); static struct attribute *hsw_events_attrs[] = { EVENT_PTR(tx_start), @@ -2053,6 +2054,7 @@ static struct attribute *hsw_events_attrs[] = { EVENT_PTR(cycles_ct), EVENT_PTR(instructions_t), EVENT_PTR(instructions_ct), + EVENT_PTR(instructions_p), NULL }; -- 1.7.7.6 -- 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/