From: "H. Peter Anvin" <hpa@zytor.com>
To: rostedt@goodmis.org
Cc: David Daney <ddaney@caviumnetworks.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Haley <aph@redhat.com>,
Richard Guenther <richard.guenther@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@elte.hu>,
LKML <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
feng.tang@intel.com,
Fr??d??ric Weisbecker <fweisbec@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
jakub@redhat.com, gcc@gcc.gnu.org
Subject: Re: BUG: GCC-4.4.x changes the function frame on some functions
Date: Thu, 19 Nov 2009 19:51:00 -0000 [thread overview]
Message-ID: <4B05A16D.1050807@zytor.com> (raw)
In-Reply-To: <1258658886.22249.874.camel@gandalf.stny.rr.com>
On 11/19/2009 11:28 AM, Steven Rostedt wrote:
>
> Hehe, scratch register on i686 ;-)
>
> i686 has no extra regs. It just has:
>
> %eax, %ebx, %ecx, %edx - as the general purpose regs
> %esp - stack
> %ebp - frame pointer
> %edi, %esi - counter regs
>
> That's just 8 regs, and half of those are special.
>
For a modern ABI it is better described as:
%eax, %edx, %ecx - argument/return/scratch registers
%ebx, %esi, %edi - saved registers
%esp - stack pointer
%ebp - frame pointer (saved)
> Perhaps we could create another profiler? Instead of calling mcount,
> call a new function: __fentry__ or something. Have it activated with
> another switch. This could make the performance of the function tracer
> even better without all these exceptions.
>
> <function>:
> call __fentry__
> [...]
>
Calling the profiler immediately at the entry point is clearly the more
sane option. It means the ABI is well-defined, stable, and independent
of what the actual function contents are. It means that ABI isn't the
normal C ABI (the __fentry__ function would have to preserve all
registers), but that's fine...
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
next prev parent reply other threads:[~2009-11-19 19:51 UTC|newest]
Thread overview: 99+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <alpine.LFD.2.00.0911181933540.24119@localhost.localdomain>
[not found] ` <tip-887a29f59b93cf54e21814869a4ab6e80b6fa623@git.kernel.org>
[not found] ` <20091119072040.GA23579@elte.hu>
[not found] ` <alpine.LFD.2.00.0911191053390.24119@localhost.localdomain>
[not found] ` <alpine.LFD.2.00.0911191423190.24119@localhost.localdomain>
2009-11-19 15:39 ` Thomas Gleixner
2009-11-19 15:45 ` Andrew Haley
2009-11-19 15:55 ` H. Peter Anvin
2009-11-19 15:59 ` Richard Guenther
2009-11-19 16:03 ` Steven Rostedt
2009-11-19 16:13 ` H. Peter Anvin
2009-11-19 16:20 ` Frederic Weisbecker
2009-11-19 16:07 ` Thomas Gleixner
2009-11-19 16:19 ` Andrew Haley
2009-11-19 16:45 ` Thomas Gleixner
2009-11-19 16:13 ` Steven Rostedt
2009-11-19 15:46 ` H. Peter Anvin
2009-11-19 15:51 ` Richard Guenther
2009-11-19 15:53 ` Richard Guenther
2009-11-19 17:38 ` Andi Kleen
2009-11-19 17:41 ` Linus Torvalds
2009-11-19 17:52 ` Thomas Gleixner
2009-11-19 18:00 ` Steven Rostedt
2009-11-19 18:04 ` Richard Guenther
2009-11-19 18:23 ` Andrew Haley
2009-11-19 18:42 ` Linus Torvalds
2009-11-19 18:45 ` Linus Torvalds
2009-11-19 18:56 ` Linus Torvalds
2009-11-19 19:03 ` Thomas Gleixner
2009-11-23 9:17 ` Jakub Jelinek
2009-11-23 9:53 ` Thomas Gleixner
2009-11-19 19:12 ` David Daney
2009-11-19 19:29 ` Steven Rostedt
2009-11-19 19:47 ` Frederic Weisbecker
2009-11-19 19:55 ` Kai Tietz
2009-11-19 20:06 ` Frederic Weisbecker
2009-11-19 20:06 ` Steven Rostedt
2009-11-19 20:18 ` Steven Rostedt
2009-11-19 20:29 ` Frederic Weisbecker
2009-11-19 20:26 ` Frederic Weisbecker
2009-11-19 20:38 ` Linus Torvalds
2009-11-19 20:45 ` Steven Rostedt
2009-11-19 19:51 ` H. Peter Anvin [this message]
2009-11-19 20:08 ` Linus Torvalds
2009-11-19 21:13 ` Jeff Law
2009-11-19 20:11 ` Steven Rostedt
2009-11-19 21:07 ` Jeff Law
2009-11-19 18:34 ` Thomas Gleixner
2009-11-19 18:40 ` Linus Torvalds
2009-11-19 18:48 ` Ingo Molnar
2009-11-19 19:08 ` Steven Rostedt
2009-11-19 19:51 ` Ingo Molnar
2009-11-20 9:58 ` [PATCH] gcc mcount-nofp was " Andi Kleen
2009-11-20 12:35 ` Steven Rostedt
2009-11-20 19:08 ` H. Peter Anvin
2009-11-19 20:37 ` Thomas Gleixner
2009-11-19 18:22 ` Andrew Haley
2009-11-19 18:34 ` Steven Rostedt
2009-11-19 18:37 ` Andrew Pinski
2009-11-19 18:38 ` H. Peter Anvin
2009-11-19 18:38 ` Andrew Haley
2009-11-19 18:40 ` Thomas Gleixner
2009-11-20 5:24 ` [PATCH][GIT PULL][v2.6.32] tracing/x86: Add check to detect GCC messing with mcount prologue Steven Rostedt
2009-11-20 5:33 ` Steven Rostedt
2009-11-20 17:02 ` Steven Rostedt
2009-11-20 17:15 ` H. Peter Anvin
2009-11-20 19:36 ` Andrew Haley
2009-11-20 19:48 ` Steven Rostedt
2009-11-20 19:50 ` H. Peter Anvin
2009-11-22 9:39 ` H.J. Lu
2009-11-22 17:21 ` Andrew Haley
2009-11-22 23:31 ` H.J. Lu
2009-11-24 14:43 ` Andrew Haley
2009-11-24 14:56 ` Thomas Gleixner
2009-11-24 15:06 ` Jakub Jelinek
2009-11-24 15:32 ` Andrew Haley
2009-11-24 15:36 ` Jakub Jelinek
2009-11-24 15:48 ` Andrew Haley
2009-11-24 16:39 ` H. Peter Anvin
2009-11-24 17:12 ` Andrew Haley
2009-11-24 17:30 ` Steven Rostedt
2009-11-25 20:05 ` H. Peter Anvin
2009-11-24 19:56 ` H. Peter Anvin
2009-11-25 15:29 ` Thomas Gleixner
2009-11-25 15:45 ` Ingo Molnar
2009-11-25 15:53 ` Thomas Gleixner
2009-11-25 16:26 ` Ingo Molnar
2009-11-25 16:45 ` Jakub Jelinek
2009-11-25 20:13 ` H. Peter Anvin
2009-11-25 21:01 ` Andrew Haley
2009-11-22 9:06 ` Ingo Molnar
2009-11-19 21:16 BUG: GCC-4.4.x changes the function frame on some functions H. Peter Anvin
2009-11-19 21:26 ` Jeff Law
2009-11-19 22:44 ` Steven Rostedt
2009-11-20 0:00 ` Jeff Law
2009-11-20 0:37 ` Thomas Gleixner
2009-11-20 1:00 ` Linus Torvalds
2009-11-20 1:29 ` Thomas Gleixner
2009-11-20 2:16 ` Thomas Gleixner
2009-11-20 1:30 ` H. Peter Anvin
2009-11-20 5:40 ` Ingo Molnar
2009-11-20 12:06 ` Andrew Haley
2009-11-20 12:23 ` Andrew Haley
-- strict thread matches above, loose matches on Subject: below --
2009-11-19 20:50 H. Peter Anvin
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