From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Ellerman Subject: Re: [RFC PATCH 2/2] powerpc: Only support DYNAMIC_FTRACE not static Date: Mon, 19 Mar 2018 12:08:10 +1100 Message-ID: <87efkghnyd.fsf@concordia.ellerman.id.au> References: <20180316134633.10584-1-mpe@ellerman.id.au> <20180316134633.10584-2-mpe@ellerman.id.au> <20180316104248.6aa11792@gandalf.local.home> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <20180316104248.6aa11792@gandalf.local.home> Sender: linux-kernel-owner@vger.kernel.org To: Steven Rostedt Cc: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, naveen.n.rao@linux.vnet.ibm.com List-Id: linux-arch.vger.kernel.org Steven Rostedt writes: > On Sat, 17 Mar 2018 00:46:33 +1100 > Michael Ellerman wrote: > >> We've had dynamic ftrace support for over 9 years since Steve first >> wrote it, all the distros use dynamic, and static is basically >> untested these days, so drop support for static ftrace. >> >> Signed-off-by: Michael Ellerman >> --- >> arch/powerpc/Kconfig | 1 + >> arch/powerpc/include/asm/ftrace.h | 4 +--- >> arch/powerpc/include/asm/module.h | 5 ----- >> arch/powerpc/kernel/trace/ftrace.c | 2 -- >> arch/powerpc/kernel/trace/ftrace_32.S | 20 ------------------ >> arch/powerpc/kernel/trace/ftrace_64.S | 29 -------------------------- >> arch/powerpc/kernel/trace/ftrace_64_mprofile.S | 3 --- >> arch/powerpc/kernel/trace/ftrace_64_pg.S | 2 -- >> 8 files changed, 2 insertions(+), 64 deletions(-) >> >> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig >> index 73ce5dd07642..23a325df784a 100644 >> --- a/arch/powerpc/Kconfig >> +++ b/arch/powerpc/Kconfig >> @@ -189,6 +189,7 @@ config PPC >> select HAVE_DEBUG_STACKOVERFLOW >> select HAVE_DMA_API_DEBUG >> select HAVE_DYNAMIC_FTRACE >> + select HAVE_DYNAMIC_FTRACE_ONLY > > I still think adding: > > select DYNAMIC_FTRACE if FUNCTION_TRACER > > is the better approach. OK. As I said in my other reply it's a bit fragile, but it does work. I'll do a version for powerpc using the above approach. > But I'm all for this patch. I've debated doing the same thing for x86, > but the only reason I have not, was because it's the only way I test > the !DYNAMIC_FTRACE code. I've broken the static function tracing > several times and only find out during my test suite that still tests > that case. But yeah, it would be nice to just nuke static function > tracing for all archs. Perhaps after we finish removing unused archs, > that may be the way to go forward. Yeah I did look and we still have some arches that support ftrace but not dynamic ftrace, but there's not many. cheers From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org ([103.22.144.67]:51309 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754218AbeCSBIM (ORCPT ); Sun, 18 Mar 2018 21:08:12 -0400 From: Michael Ellerman Subject: Re: [RFC PATCH 2/2] powerpc: Only support DYNAMIC_FTRACE not static In-Reply-To: <20180316104248.6aa11792@gandalf.local.home> References: <20180316134633.10584-1-mpe@ellerman.id.au> <20180316134633.10584-2-mpe@ellerman.id.au> <20180316104248.6aa11792@gandalf.local.home> Date: Mon, 19 Mar 2018 12:08:10 +1100 Message-ID: <87efkghnyd.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-arch-owner@vger.kernel.org List-ID: To: Steven Rostedt Cc: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, naveen.n.rao@linux.vnet.ibm.com Message-ID: <20180319010810.ie2tz37P_IOxcosuqku3a3fDtWpIFG1sBKnaFgo--KU@z> Steven Rostedt writes: > On Sat, 17 Mar 2018 00:46:33 +1100 > Michael Ellerman wrote: > >> We've had dynamic ftrace support for over 9 years since Steve first >> wrote it, all the distros use dynamic, and static is basically >> untested these days, so drop support for static ftrace. >> >> Signed-off-by: Michael Ellerman >> --- >> arch/powerpc/Kconfig | 1 + >> arch/powerpc/include/asm/ftrace.h | 4 +--- >> arch/powerpc/include/asm/module.h | 5 ----- >> arch/powerpc/kernel/trace/ftrace.c | 2 -- >> arch/powerpc/kernel/trace/ftrace_32.S | 20 ------------------ >> arch/powerpc/kernel/trace/ftrace_64.S | 29 -------------------------- >> arch/powerpc/kernel/trace/ftrace_64_mprofile.S | 3 --- >> arch/powerpc/kernel/trace/ftrace_64_pg.S | 2 -- >> 8 files changed, 2 insertions(+), 64 deletions(-) >> >> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig >> index 73ce5dd07642..23a325df784a 100644 >> --- a/arch/powerpc/Kconfig >> +++ b/arch/powerpc/Kconfig >> @@ -189,6 +189,7 @@ config PPC >> select HAVE_DEBUG_STACKOVERFLOW >> select HAVE_DMA_API_DEBUG >> select HAVE_DYNAMIC_FTRACE >> + select HAVE_DYNAMIC_FTRACE_ONLY > > I still think adding: > > select DYNAMIC_FTRACE if FUNCTION_TRACER > > is the better approach. OK. As I said in my other reply it's a bit fragile, but it does work. I'll do a version for powerpc using the above approach. > But I'm all for this patch. I've debated doing the same thing for x86, > but the only reason I have not, was because it's the only way I test > the !DYNAMIC_FTRACE code. I've broken the static function tracing > several times and only find out during my test suite that still tests > that case. But yeah, it would be nice to just nuke static function > tracing for all archs. Perhaps after we finish removing unused archs, > that may be the way to go forward. Yeah I did look and we still have some arches that support ftrace but not dynamic ftrace, but there's not many. cheers