From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756882AbZBDP0c (ORCPT ); Wed, 4 Feb 2009 10:26:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752462AbZBDP0U (ORCPT ); Wed, 4 Feb 2009 10:26:20 -0500 Received: from fg-out-1718.google.com ([72.14.220.159]:13148 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756664AbZBDP0S (ORCPT ); Wed, 4 Feb 2009 10:26:18 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=IyiViWgBjwxDUuidAsXgbmCzIfCIXFkiodY7WMa0xNf4obOpyrI0OeSz+O1JJl7x7Q TQSgpGFpqqazJvwUsI0QJWPsVHFcVSrxA6w8HgmBtvobgWWGtqWwSBm7pm5SqqqAnMLc UeZsaxcC6C9q8T1+Fmldx9kLdB0SM8wAVHKuE= MIME-Version: 1.0 In-Reply-To: <20090204150840.GC30027@oksana.dev.rtsoft.ru> References: <20090204150755.GA24163@oksana.dev.rtsoft.ru> <20090204150840.GC30027@oksana.dev.rtsoft.ru> Date: Wed, 4 Feb 2009 16:26:15 +0100 Message-ID: Subject: Re: [PATCH 3/3] tracing: Tracers that use CALLER_ADDR macros should select FRAME_POINTER From: =?ISO-8859-1?Q?Fr=E9d=E9ric_Weisbecker?= To: Anton Vorontsov Cc: Steven Rostedt , Ingo Molnar , Paul Mackerras , Benjamin Herrenschmidt , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2009/2/4 Anton Vorontsov : > Irqsoff, switch and preempt tracers use CALLER_ADDR macros, so they > should select FRAME_POINTER. Otherwise traces are meaningless. > > Signed-off-by: Anton Vorontsov > --- > kernel/trace/Kconfig | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig > index e2a4ff6..48f7a37 100644 > --- a/kernel/trace/Kconfig > +++ b/kernel/trace/Kconfig > @@ -86,6 +86,7 @@ config IRQSOFF_TRACER > select TRACE_IRQFLAGS > select TRACING > select TRACER_MAX_TRACE > + select FRAME_POINTER > help > This option measures the time spent in irqs-off critical > sections, with microsecond accuracy. > @@ -108,6 +109,7 @@ config PREEMPT_TRACER > depends on DEBUG_KERNEL > select TRACING > select TRACER_MAX_TRACE > + select FRAME_POINTER > help > This option measures the time spent in preemption off critical > sections, with microsecond accuracy. > @@ -136,6 +138,7 @@ config SCHED_TRACER > select TRACING > select CONTEXT_SWITCH_TRACER > select TRACER_MAX_TRACE > + select FRAME_POINTER > help > This tracer tracks the latency of the highest priority task > to be scheduled in, starting from the point it has woken up. > -- Looks right. BTW, how behaves builtin_return_address in case of !FRAME_POINTERS ? I guess it would only work with the first caller builtin_return_address(0)