From: Thomas Gleixner <tglx@linutronix.de>
To: Andrew Haley <aph@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>, "H. Peter Anvin" <hpa@zytor.com>,
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>,
Steven Rostedt <rostedt@goodmis.org>,
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 16:45:00 -0000 [thread overview]
Message-ID: <alpine.LFD.2.00.0911191720030.24119@localhost.localdomain> (raw)
In-Reply-To: <4B056FAD.2080500@redhat.com>
On Thu, 19 Nov 2009, Andrew Haley wrote:
> Thomas Gleixner wrote:
> > On Thu, 19 Nov 2009, Andrew Haley wrote:
> >> Thomas Gleixner wrote:
> >>> There is no real obvious reason why the edi magic needs to be done
> >>> _before_
> >>>
> >>> push %ebp
> >>> mov %esp,%ebp
> >> Sure there is: unless you do the adjustment first %ebp won't be 16-aligned.
> >
> > And why is this not done in 99% of the functions in the kernel, just
> > in this one and some random others ?
>
> If I could see the function I might be able to tell you. It's either a
> performance enhancement, something to do with SSE, or it's a bug.
kernel/time/timer_stats.c timer_stats_update_stats()
Here is the disassembly:
8107ad50 <timer_stats_update_stats>:
8107ad50: 57 push %edi
8107ad51: 8d 7c 24 08 lea 0x8(%esp),%edi
8107ad55: 83 e4 f0 and $0xfffffff0,%esp
8107ad58: ff 77 fc pushl -0x4(%edi)
8107ad5b: 55 push %ebp
8107ad5c: 89 e5 mov %esp,%ebp
8107ad5e: 57 push %edi
8107ad5f: 56 push %esi
8107ad60: 53 push %ebx
8107ad61: 83 ec 6c sub $0x6c,%esp
8107ad64: e8 47 92 f8 ff call 81003fb0 <mcount>
8107ad69: 8b 77 04 mov 0x4(%edi),%esi
8107ad6c: 89 75 a4 mov %esi,-0x5c(%ebp)
8107ad6f: 65 8b 35 14 00 00 00 mov %gs:0x14,%esi
8107ad76: 89 75 e4 mov %esi,-0x1c(%ebp)
8107ad79: 31 f6 xor %esi,%esi
8107ad7b: 8b 35 60 5a cd 81 mov 0x81cd5a60,%esi
8107ad81: 8b 1f mov (%edi),%ebx
8107ad83: 85 f6 test %esi,%esi
8107ad85: 8b 7f 08 mov 0x8(%edi),%edi
8107ad88: 75 18 jne 8107ada2 <timer_stats_update_stats+0x52>
8107ad8a: 8b 45 e4 mov -0x1c(%ebp),%eax
8107ad8d: 65 33 05 14 00 00 00 xor %gs:0x14,%eax
8107ad94: 75 53 jne 8107ade9 <timer_stats_update_stats+0x99>
8107ad96: 83 c4 6c add $0x6c,%esp
8107ad99: 5b pop %ebx
8107ad9a: 5e pop %esi
8107ad9b: 5f pop %edi
8107ad9c: 5d pop %ebp
8107ad9d: 8d 67 f8 lea -0x8(%edi),%esp
8107ada0: 5f pop %edi
8107ada1: c3 ret
8107ada2: be 00 7a d6 81 mov $0x81d67a00,%esi
8107ada7: 89 45 ac mov %eax,-0x54(%ebp)
8107adaa: 89 75 a0 mov %esi,-0x60(%ebp)
8107adad: 89 5d b4 mov %ebx,-0x4c(%ebp)
8107adb0: 64 8b 35 78 6a d6 81 mov %fs:0x81d66a78,%esi
8107adb7: 8b 34 b5 20 50 cd 81 mov -0x7e32afe0(,%esi,4),%esi
8107adbe: 89 4d b0 mov %ecx,-0x50(%ebp)
8107adc1: 01 75 a0 add %esi,-0x60(%ebp)
8107adc4: 89 55 b8 mov %edx,-0x48(%ebp)
8107adc7: 8b 45 a0 mov -0x60(%ebp),%eax
8107adca: 89 7d c0 mov %edi,-0x40(%ebp)
8107adcd: e8 de f7 76 00 call 817ea5b0 <_spin_lock_irqsave>
8107add2: 83 3d 60 5a cd 81 00 cmpl $0x0,0x81cd5a60
8107add9: 89 c3 mov %eax,%ebx
8107addb: 75 11 jne 8107adee <timer_stats_update_stats+0x9e>
8107addd: 89 da mov %ebx,%edx
8107addf: 8b 45 a0 mov -0x60(%ebp),%eax
8107ade2: e8 79 fc 76 00 call 817eaa60 <_spin_unlock_irqrestore>
8107ade7: eb a1 jmp 8107ad8a <timer_stats_update_stats+0x3a>
8107ade9: e8 52 e4 fc ff call 81049240 <__stack_chk_fail>
8107adee: 8d 45 a8 lea -0x58(%ebp),%eax
8107adf1: 8b 55 a4 mov -0x5c(%ebp),%edx
8107adf4: e8 f7 fd ff ff call 8107abf0 <tstat_lookup>
8107adf9: 85 c0 test %eax,%eax
8107adfb: 74 05 je 8107ae02 <timer_stats_update_stats+0xb2>
8107adfd: ff 40 14 incl 0x14(%eax)
8107ae00: eb db jmp 8107addd <timer_stats_update_stats+0x8d>
8107ae02: f0 ff 05 00 67 fd 81 lock incl 0x81fd6700
8107ae09: eb d2 jmp 8107addd <timer_stats_update_stats+0x8d>
8107ae0b: 90 nop
8107ae0c: 90 nop
8107ae0d: 90 nop
8107ae0e: 90 nop
8107ae0f: 90 nop
There is a dozen more of those.
Thanks,
tglx
next prev parent reply other threads:[~2009-11-19 16:45 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 [this message]
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
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 ` Andrew Haley
2009-11-19 18:38 ` H. Peter Anvin
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 20:50 BUG: GCC-4.4.x changes the function frame on some functions H. Peter Anvin
2009-11-19 21:16 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
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