From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753523Ab3A3GbG (ORCPT ); Wed, 30 Jan 2013 01:31:06 -0500 Received: from mga14.intel.com ([143.182.124.37]:12699 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753397Ab3A3GbC (ORCPT ); Wed, 30 Jan 2013 01:31:02 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,565,1355126400"; d="scan'208";a="196543095" From: "Yan, Zheng" To: mingo@kernel.org Cc: linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, akpm@linux-foundation.org, acme@redhat.com, eranian@google.com, namhyung@kernel.org, "Yan, Zheng" Subject: [PATCH 0/7] perf, x86: Haswell LBR call stack support Date: Wed, 30 Jan 2013 14:30:50 +0800 Message-Id: <1359527457-6837-1-git-send-email-zheng.z.yan@intel.com> X-Mailer: git-send-email 1.7.11.7 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Yan, Zheng" Haswell has a new feature that utilizes the existing Last Branch Record facility to record call chains. When the feature is enabled, function call will be collected as normal, but as return instructions are executed the last captured branch record is popped from the on-chip LBR registers. The LBR call stack facility can help perf to get call chains of progam without frame pointer. When perf tool requests PERF_SAMPLE_CALLCHAIN + PERF_SAMPLE_BRANCH_USER, this feature is dynamically enabled by default. This feature can be disabled/enabled through an attribute file in the cpu pmu sysfs directory. The LBR call stack has following known limitations 1. Zero length calls are not filtered out by hardware 2. Exception handing such as setjmp/longjmp will have calls/returns not match 3. Pushing different return address onto the stack will have calls/returns not match The patch series depends on Andi's "Basic perf PMU support for Haswell v1" Available from https://github.com/ukernel/linux.git hws/pmu4 Regards Yan, Zheng