From: Andi Kleen <andi@firstfloor.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Andi Kleen <andi@firstfloor.org>,
Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>,
LKML <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
David Miller <davem@davemloft.net>,
Roland McGrath <roland@redhat.com>,
Ulrich Drepper <drepper@redhat.com>,
Rusty Russell <rusty@rustcorp.com.au>,
Jeremy Fitzhardinge <jeremy@goop.org>,
Gregory Haskins <ghaskins@novell.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
"Luis Claudio R. Goncalves" <lclaudio@uudg.org>,
Clark Williams <williams@redhat.com>
Subject: Re: [PATCH 0/5] ftrace: to kill a daemon
Date: Sat, 9 Aug 2008 03:55:39 +0200 [thread overview]
Message-ID: <20080809015539.GG9038@one.firstfloor.org> (raw)
In-Reply-To: <alpine.DEB.1.10.0808082126500.3707@gandalf.stny.rr.com>
> Funny, CONFIG_FTRACE happens to select that. Now the question is, would
> mcount work without it?
Not without fixing gcc first. It would work if gcc always called
mcount the first thing before setting up the stack frame. Not
sure why it doesn't do that.
Still do a benchmark of frame pointer vs no frame pointer kernel
and you'll see, especially on a older CPUs without special hardware
to avoid stack stalls (e.g. not Core2)
BTW always forcing frame pointers also means that ftrace is far
from near zero overhead even when disabled. That is unless you
find a way to nop the frame pointers too, but that would be likely
very difficult because the code will actually use it.
-Andi
next prev parent reply other threads:[~2008-08-09 1:54 UTC|newest]
Thread overview: 107+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-07 18:20 [PATCH 0/5] ftrace: to kill a daemon Steven Rostedt
2008-08-07 18:20 ` [PATCH 1/5] ftrace: create __mcount_loc section Steven Rostedt
2008-08-07 18:20 ` [PATCH 2/5] ftrace: mcount call site on boot nops core Steven Rostedt
2008-08-07 18:20 ` [PATCH 3/5] ftrace: enable mcount recording for modules Steven Rostedt
2008-08-08 6:43 ` Rusty Russell
2008-08-08 12:51 ` Steven Rostedt
2008-08-07 18:20 ` [PATCH 4/5] ftrace: rebuild everything on change to FTRACE_MCOUNT_RECORD Steven Rostedt
2008-08-07 18:20 ` [PATCH 5/5] ftrace: enable using mcount recording on x86 Steven Rostedt
2008-08-07 18:47 ` [PATCH 0/5] ftrace: to kill a daemon Mathieu Desnoyers
2008-08-07 20:42 ` Steven Rostedt
2008-08-08 17:22 ` Mathieu Desnoyers
2008-08-08 17:36 ` Steven Rostedt
2008-08-08 17:46 ` Mathieu Desnoyers
2008-08-08 18:13 ` Steven Rostedt
2008-08-08 18:15 ` Peter Zijlstra
2008-08-08 18:21 ` Mathieu Desnoyers
2008-08-08 18:41 ` Steven Rostedt
2008-08-08 19:04 ` Linus Torvalds
2008-08-08 19:05 ` Mathieu Desnoyers
2008-08-08 23:38 ` Steven Rostedt
2008-08-09 0:23 ` Andi Kleen
2008-08-09 0:36 ` Steven Rostedt
2008-08-09 0:47 ` Jeremy Fitzhardinge
2008-08-09 0:51 ` Linus Torvalds
2008-08-09 1:25 ` Steven Rostedt
2008-08-13 6:31 ` Mathieu Desnoyers
2008-08-13 15:38 ` Mathieu Desnoyers
2008-08-13 17:52 ` Efficient x86 and x86_64 NOP microbenchmarks Mathieu Desnoyers
2008-08-13 18:27 ` Linus Torvalds
2008-08-13 18:41 ` Andi Kleen
2008-08-13 18:45 ` Avi Kivity
2008-08-13 18:51 ` Andi Kleen
2008-08-13 18:56 ` Avi Kivity
2008-08-13 19:30 ` Mathieu Desnoyers
2008-08-13 19:37 ` Andi Kleen
2008-08-13 20:01 ` Mathieu Desnoyers
2008-08-13 23:41 ` [RFC PATCH] x86 alternatives : fix LOCK_PREFIX race with preemptible kernel and CPU hotplug Mathieu Desnoyers
2008-08-14 0:01 ` H. Peter Anvin
2008-08-14 1:13 ` Mathieu Desnoyers
2008-08-14 1:22 ` Jeremy Fitzhardinge
2008-08-14 1:26 ` Roland McGrath
2008-08-14 1:49 ` Mathieu Desnoyers
2008-08-14 3:35 ` Jeremy Fitzhardinge
2008-08-14 15:18 ` Mathieu Desnoyers
2008-08-14 16:10 ` Linus Torvalds
2008-08-14 16:13 ` H. Peter Anvin
2008-08-14 16:58 ` Mathieu Desnoyers
2008-08-14 17:05 ` Jeremy Fitzhardinge
2008-08-14 17:30 ` Mathieu Desnoyers
2008-08-14 17:43 ` Jeremy Fitzhardinge
2008-08-14 18:37 ` H. Peter Anvin
2008-08-14 18:53 ` Mathieu Desnoyers
2008-08-14 19:29 ` Jeremy Fitzhardinge
2008-08-14 20:31 ` Mathieu Desnoyers
2008-08-14 20:39 ` H. Peter Anvin
2008-08-14 21:46 ` Jeremy Fitzhardinge
2008-08-14 22:26 ` H. Peter Anvin
2008-08-14 17:17 ` H. Peter Anvin
2008-08-14 18:09 ` Mathieu Desnoyers
2008-08-14 19:49 ` Mathieu Desnoyers
2008-08-14 17:04 ` Jeremy Fitzhardinge
2008-08-14 17:18 ` H. Peter Anvin
2008-08-14 17:28 ` Jeremy Fitzhardinge
2008-08-14 17:31 ` H. Peter Anvin
2008-08-14 17:46 ` Mathieu Desnoyers
2008-08-14 17:49 ` Jeremy Fitzhardinge
2008-08-14 17:55 ` Mathieu Desnoyers
2008-08-14 18:59 ` Gregory Haskins
2008-08-15 21:34 ` Efficient x86 and x86_64 NOP microbenchmarks Steven Rostedt
2008-08-15 21:51 ` Andi Kleen
2008-08-13 19:16 ` Mathieu Desnoyers
2008-08-09 0:51 ` [PATCH 0/5] ftrace: to kill a daemon Steven Rostedt
2008-08-09 0:53 ` Roland McGrath
2008-08-09 1:13 ` Andi Kleen
2008-08-09 1:19 ` Andi Kleen
2008-08-09 1:30 ` Steven Rostedt
2008-08-09 1:55 ` Andi Kleen [this message]
2008-08-09 2:03 ` Steven Rostedt
2008-08-09 2:23 ` Andi Kleen
2008-08-09 4:12 ` Steven Rostedt
2008-08-09 0:30 ` Steven Rostedt
2008-08-11 18:21 ` Mathieu Desnoyers
2008-08-11 19:28 ` Steven Rostedt
2008-08-08 19:08 ` Jeremy Fitzhardinge
2008-08-11 2:41 ` Rusty Russell
2008-08-11 12:33 ` Steven Rostedt
2008-08-07 21:11 ` Jeremy Fitzhardinge
2008-08-07 21:29 ` Steven Rostedt
2008-08-07 22:26 ` Roland McGrath
2008-08-08 1:21 ` Steven Rostedt
2008-08-08 1:24 ` Steven Rostedt
2008-08-08 1:56 ` Steven Rostedt
2008-08-08 7:22 ` Peter Zijlstra
2008-08-08 11:31 ` Steven Rostedt
2008-08-08 4:54 ` Sam Ravnborg
2008-08-09 9:48 ` Abhishek Sagar
2008-08-09 13:01 ` Steven Rostedt
2008-08-09 15:01 ` Abhishek Sagar
2008-08-09 15:37 ` Steven Rostedt
2008-08-09 17:14 ` Abhishek Sagar
[not found] <aYipy-5FM-9@gated-at.bofh.it>
2008-08-07 21:28 ` Bodo Eggert
2008-08-07 21:24 ` Jeremy Fitzhardinge
2008-08-07 21:35 ` Steven Rostedt
[not found] ` <aYiIP-6bN-11@gated-at.bofh.it>
[not found] ` <aYkAT-15Q-1@gated-at.bofh.it>
[not found] ` <aYDX5-fa-31@gated-at.bofh.it>
[not found] ` <aYE6H-tg-21@gated-at.bofh.it>
[not found] ` <aYEgj-Fc-17@gated-at.bofh.it>
[not found] ` <aYEJq-1xB-23@gated-at.bofh.it>
[not found] ` <aYET8-1L7-17@gated-at.bofh.it>
[not found] ` <aYFcq-2f2-11@gated-at.bofh.it>
[not found] ` <aYFvP-2Vc-25@gated-at.bofh.it>
[not found] ` <aYJIZ-15G-7@gated-at.bofh.it>
[not found] ` <aYKvs-2gQ-7@gated-at.bofh.it>
[not found] ` <aYKF1-2qs-7@gated-at.bofh.it>
2008-08-09 11:50 ` Bodo Eggert
2008-08-09 13:02 ` Steven Rostedt
2008-08-09 14:25 ` Steven Rostedt
2008-08-09 14:42 ` Bodo Eggert
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