From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754220AbZCELEU (ORCPT ); Thu, 5 Mar 2009 06:04:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751257AbZCELEI (ORCPT ); Thu, 5 Mar 2009 06:04:08 -0500 Received: from hera.kernel.org ([140.211.167.34]:45453 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750810AbZCELEG (ORCPT ); Thu, 5 Mar 2009 06:04:06 -0500 Date: Thu, 5 Mar 2009 11:03:33 GMT From: Frederic Weisbecker To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, fweisbec@gmail.com, rostedt@goodmis.org, peterz@infradead.org, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, fweisbec@gmail.com, rostedt@goodmis.org, peterz@infradead.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <49af243d.06e9300a.53ad.ffff840c@mx.google.com> References: <49af243d.06e9300a.53ad.ffff840c@mx.google.com> Subject: [tip:tracing/function-graph-tracer] tracing/function-graph-tracer: use the more lightweight local clock Message-ID: Git-Commit-ID: bf467399b5f6301e7a6dc21460e66b1f40e16c7e X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Thu, 05 Mar 2009 11:03:35 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: bf467399b5f6301e7a6dc21460e66b1f40e16c7e Gitweb: http://git.kernel.org/tip/bf467399b5f6301e7a6dc21460e66b1f40e16c7e Author: "Frederic Weisbecker" AuthorDate: Thu, 5 Mar 2009 01:49:22 +0100 Commit: Ingo Molnar CommitDate: Thu, 5 Mar 2009 12:01:52 +0100 tracing/function-graph-tracer: use the more lightweight local clock Impact: decrease hangs risks with the graph tracer on slow systems Since the function graph tracer can spend too much time on timer interrupts, it's better now to use the more lightweight local clock. Anyway, the function graph traces are more reliable on a per cpu trace. Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Peter Zijlstra LKML-Reference: <49af243d.06e9300a.53ad.ffff840c@mx.google.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/ftrace.c | 2 +- kernel/trace/trace_functions_graph.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 3925ec0..a85da17 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -436,7 +436,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) return; } - calltime = cpu_clock(raw_smp_processor_id()); + calltime = trace_clock_local(); if (ftrace_push_return_trace(old, calltime, self_addr, &trace.depth) == -EBUSY) { diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index c009553..e527f2f 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -112,7 +112,7 @@ unsigned long ftrace_return_to_handler(void) unsigned long ret; ftrace_pop_return_trace(&trace, &ret); - trace.rettime = cpu_clock(raw_smp_processor_id()); + trace.rettime = trace_clock_local(); ftrace_graph_return(&trace); if (unlikely(!ret)) {