From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753446AbYKZANT (ORCPT ); Tue, 25 Nov 2008 19:13:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752353AbYKZANI (ORCPT ); Tue, 25 Nov 2008 19:13:08 -0500 Received: from qw-out-2122.google.com ([74.125.92.24]:38320 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752295AbYKZANG (ORCPT ); Tue, 25 Nov 2008 19:13:06 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=E1xQEbCQgNrqK84EYwRaPgYd7x1pIS0pEqHCb/lTKJwT4W654gZlkCu41oszbg5P+X XUOBGAfeX7emeEDLottccFf1cne4olfouqOr6WVCVTGAq2UkEG+UWjjDHp85GZfiPw4s CunKaBpNBFkJnQAVNMx+YwVX4r4+CGgyTyOzo= Message-ID: Date: Wed, 26 Nov 2008 01:13:04 +0100 From: "=?ISO-8859-1?Q?Fr=E9d=E9ric_Weisbecker?=" To: "Steven Rostedt" Subject: Re: [PATCH 2/3] ftrace: use code patching for ftrace return tracer Cc: linux-kernel@vger.kernel.org, "Ingo Molnar" , "Andrew Morton" , "Steven Rostedt" In-Reply-To: <20081125223457.162461633@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20081125223421.795046329@goodmis.org> <20081125223457.162461633@goodmis.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2008/11/25 Steven Rostedt : > From: Steven Rostedt > > Impact: more efficient code for ftrace return tracer > > This patch uses the dynamic patching, when available, to patch > the function return code into the kernel. > > This patch will ease the way for letting both function tracing > and function return tracing run together. > > Signed-off-by: Steven Rostedt > --- > arch/x86/kernel/entry_32.S | 5 ++++ > arch/x86/kernel/ftrace.c | 46 +++++++++++++++++++++++++++++++++++++++++++- > include/linux/ftrace.h | 5 ++++ > kernel/trace/ftrace.c | 34 ++++++++++++++------------------ > 4 files changed, 70 insertions(+), 20 deletions(-) > > diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S > index 7a934c0..d6f0333 100644 > --- a/arch/x86/kernel/entry_32.S > +++ b/arch/x86/kernel/entry_32.S > @@ -1185,6 +1185,11 @@ ftrace_call: > popl %edx > popl %ecx > popl %eax > +#ifdef CONFIG_FUNCTION_RET_TRACER > +.globl ftrace_return_call > +ftrace_return_call: > + jmp ftrace_stub > +#endif And you patch ftrace_stub to ftrace_return_caller. I see... Seems a good idea :-) Acked-by: Frederic Weisbecker