From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752259AbaB1OC2 (ORCPT ); Fri, 28 Feb 2014 09:02:28 -0500 Received: from mga11.intel.com ([192.55.52.93]:8266 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752027AbaB1OC0 (ORCPT ); Fri, 28 Feb 2014 09:02:26 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,562,1389772800"; d="scan'208";a="483589613" From: Andi Kleen To: acme@infradead.org Cc: linux-kernel@vger.kernel.org, Andi Kleen , eranian@google.com Subject: [PATCH 1/2] perf, tools, mem: Clarify load-latency in documentation Date: Fri, 28 Feb 2014 06:02:14 -0800 Message-Id: <1393596135-4227-2-git-send-email-andi@firstfloor.org> X-Mailer: git-send-email 1.8.5.3 In-Reply-To: <1393596135-4227-1-git-send-email-andi@firstfloor.org> References: <1393596135-4227-1-git-send-email-andi@firstfloor.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andi Kleen Clarify in the documentation that perf mem report reports use-latency, not load/store-latency on Intel systems. This often causes confusion with users. Cc: eranian@google.com Signed-off-by: Andi Kleen --- tools/perf/Documentation/perf-mem.txt | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/perf/Documentation/perf-mem.txt b/tools/perf/Documentation/perf-mem.txt index 888d511..1d78a40 100644 --- a/tools/perf/Documentation/perf-mem.txt +++ b/tools/perf/Documentation/perf-mem.txt @@ -18,6 +18,10 @@ from it, into perf.data. Perf record options are accepted and are passed through "perf mem -t report" displays the result. It invokes perf report with the right set of options to display a memory access profile. +Note that on Intel systems the memory latency reported is the use-latency, +not the pure load (or store latency). Use latency includes any pipeline +queueing delays in addition to the memory subsystem latency. + OPTIONS ------- ...:: -- 1.8.5.3