From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: avorontsov@ru.mvista.com
Cc: linuxppc-dev@ozlabs.org, Steven Rostedt <srostedt@redhat.com>,
Paul Mackerras <paulus@samba.org>, Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] ftrace: On PowerPC we don't need frame pointers for CALLER_ADDRs
Date: Wed, 04 Feb 2009 11:34:03 +1100 [thread overview]
Message-ID: <1233707643.16867.115.camel@pasglop> (raw)
In-Reply-To: <20090203185933.GA9878@oksana.dev.rtsoft.ru>
On Tue, 2009-02-03 at 21:59 +0300, Anton Vorontsov wrote:
> On Tue, Feb 03, 2009 at 11:32:18AM -0500, Steven Rostedt wrote:
> >
> > On Tue, 2009-02-03 at 19:19 +0300, Anton Vorontsov wrote:
> > > On Tue, Feb 03, 2009 at 05:06:45PM +0100, Ingo Molnar wrote:
> >
> > > [1] Btw, why exactly do we need the -fno-omit-frame-pointer for
> > > "FUNCTION_TRCER" tracer? Why just -pg isn't sufficient?..
> > >
> >
> > The problem is this that is in the toplevel Makefile:
> >
> >
> > ifdef CONFIG_FRAME_POINTER
> > KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
> > else
> > KBUILD_CFLAGS += -fomit-frame-pointer
> > endif
> >
And don't forget the gcc bug that miscompiles function epilogues on ppc
with -fno-omit-frame-pointer (iirc), which we need to work around using
-mno-sched-epilog.
Currently, we set that only if CONFIG_FUNCTION_TRACER is set, ie, we
assume that we only set -fno-omit-frame-pointer when
CONFIG_FUNCTION_TRACER is set.
Ben.
next prev parent reply other threads:[~2009-02-04 0:34 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-31 19:06 [PATCH] ftrace: On PowerPC we don't need frame pointers for CALLER_ADDRs Anton Vorontsov
2009-02-02 0:35 ` Benjamin Herrenschmidt
2009-02-02 14:04 ` Steven Rostedt
2009-02-03 14:56 ` [PATCH v2] " Anton Vorontsov
2009-02-03 16:06 ` Ingo Molnar
2009-02-03 16:19 ` Anton Vorontsov
2009-02-03 16:32 ` Steven Rostedt
2009-02-03 18:59 ` Anton Vorontsov
2009-02-04 0:34 ` Benjamin Herrenschmidt [this message]
2009-02-04 15:07 ` Anton Vorontsov
2009-02-04 15:08 ` [PATCH 1/3] Makefile: Include arch Makefiles as late as possible Anton Vorontsov
2009-02-04 21:26 ` Ingo Molnar
2009-02-11 3:51 ` Benjamin Herrenschmidt
2009-02-11 13:23 ` Ingo Molnar
2009-02-11 14:11 ` Steven Rostedt
2009-02-14 19:58 ` Sam Ravnborg
2009-02-14 19:57 ` Sam Ravnborg
2009-02-14 22:03 ` Ingo Molnar
2009-02-15 0:19 ` Benjamin Herrenschmidt
2009-02-15 8:09 ` Ingo Molnar
2009-02-16 14:20 ` Anton Vorontsov
2009-02-16 14:53 ` Anton Vorontsov
2009-02-16 20:04 ` Sam Ravnborg
2009-02-16 16:08 ` Anton Vorontsov
2009-02-16 17:22 ` Ingo Molnar
2009-02-04 15:08 ` [PATCH 2/3] powerpc: Make it possible to safely select CONFIG_FRAME_POINTER Anton Vorontsov
2009-02-05 0:31 ` Benjamin Herrenschmidt
2009-02-05 0:35 ` Steven Rostedt
2009-02-05 1:12 ` Anton Vorontsov
2009-02-05 1:15 ` Benjamin Herrenschmidt
2009-02-05 1:30 ` Anton Vorontsov
2009-02-05 15:45 ` Anton Vorontsov
2009-02-04 15:08 ` [PATCH 3/3] tracing: Tracers that use CALLER_ADDR macros should select FRAME_POINTER Anton Vorontsov
2009-02-04 15:26 ` Frédéric Weisbecker
2009-02-04 15:31 ` Steven Rostedt
2009-02-04 15:36 ` Anton Vorontsov
2009-02-04 16:50 ` Frédéric Weisbecker
2009-02-04 8:17 ` [PATCH v2] ftrace: On PowerPC we don't need frame pointers forCALLER_ADDRs Usha Rani Konudula
2009-02-04 8:37 ` Usha Rani Konudula
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