From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752506AbZLaObe (ORCPT ); Thu, 31 Dec 2009 09:31:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752392AbZLaObd (ORCPT ); Thu, 31 Dec 2009 09:31:33 -0500 Received: from hera.kernel.org ([140.211.167.34]:57094 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752178AbZLaObc (ORCPT ); Thu, 31 Dec 2009 09:31:32 -0500 Date: Thu, 31 Dec 2009 14:30:33 GMT From: tip-bot for Frederic Weisbecker Cc: linux-kernel@vger.kernel.org, paulus@samba.org, acme@redhat.com, hpa@zytor.com, mingo@redhat.com, peterz@infradead.org, fweisbec@gmail.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, acme@redhat.com, paulus@samba.org, linux-kernel@vger.kernel.org, fweisbec@gmail.com, peterz@infradead.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <1262235183-5320-1-git-send-regression-fweisbec@gmail.com> References: <1262235183-5320-1-git-send-regression-fweisbec@gmail.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf: Pass appropriate frame pointer to dump_trace() Message-ID: Git-Commit-ID: 48b5ba9cc98d676712da29d9931f1c88e5185ff2 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 48b5ba9cc98d676712da29d9931f1c88e5185ff2 Gitweb: http://git.kernel.org/tip/48b5ba9cc98d676712da29d9931f1c88e5185ff2 Author: Frederic Weisbecker AuthorDate: Thu, 31 Dec 2009 05:53:02 +0100 Committer: Ingo Molnar CommitDate: Thu, 31 Dec 2009 13:11:31 +0100 perf: Pass appropriate frame pointer to dump_trace() Pass the frame pointer from the regs of the interrupted path to dump_trace() while processing the stack trace. Currently, dump_trace() takes the current bp and starts the callchain from dump_trace() itself. This is wasteful because we need to walk through the entire NMI/DEBUG stack before retrieving the interrupted point. We can fix that by just using the frame pointer from the captured regs. It points exactly where we want to start. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras LKML-Reference: <1262235183-5320-1-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras --- arch/x86/kernel/cpu/perf_event.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index c223b7e..d616c06 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -2347,7 +2347,7 @@ perf_callchain_kernel(struct pt_regs *regs, struct perf_callchain_entry *entry) callchain_store(entry, PERF_CONTEXT_KERNEL); callchain_store(entry, regs->ip); - dump_trace(NULL, regs, NULL, 0, &backtrace_ops, entry); + dump_trace(NULL, regs, NULL, regs->bp, &backtrace_ops, entry); } /*