From: Jeff Law <law@redhat.com>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: rostedt@goodmis.org, 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 14:25:01 -0700 [thread overview]
Message-ID: <4B05B7AD.20500@redhat.com> (raw)
In-Reply-To: <viy9pk4xossnb6m2v041qu00.1258665258503@email.android.com>
On 11/19/09 14:14, H. Peter Anvin wrote:
> Hence a new unconstrained option...
>
Not arguing against it, just noting there are targets where after the
prologue mcount is mandated. There's certainly hooks in GCC to do it
both ways and if there's no clear need to use after-prologue on
x86-linux, then before-prologue seems reasonable to me.
It's also the case that aligning stacks on the x86 and the poor code
generated when used with profiling is an interaction I doubt anyone has
looked at until now. The result is definitely ugly and inefficient --
and there's something to be said for cleaning that up and at least
marginally reducing the overhead of profiling.
Having said all that, I don't expect to personally be looking at the
problem, given the list of other codegen issues that need to be looked
at (reload in particular), profiling/stack interactions would be around
87 millionth on my list.
jeff
next prev parent reply other threads:[~2009-11-19 21:27 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-19 21:14 BUG: GCC-4.4.x changes the function frame on some functions H. Peter Anvin
2009-11-19 21:25 ` Jeff Law [this message]
2009-11-19 22:43 ` Steven Rostedt
2009-11-19 23:58 ` Jeff Law
2009-11-20 0:36 ` Thomas Gleixner
2009-11-20 0:59 ` Linus Torvalds
2009-11-20 1:27 ` Thomas Gleixner
2009-11-20 2:14 ` Thomas Gleixner
2009-11-20 13:09 ` [tip:x86/urgent] x86: Prevent GCC 4.4.x (pentium-mmx et al) function prologue wreckage tip-bot for Thomas Gleixner
2009-11-20 1:29 ` BUG: GCC-4.4.x changes the function frame on some functions H. Peter Anvin
2009-11-20 5:36 ` Ingo Molnar
2009-11-20 12:04 ` Andrew Haley
2009-11-20 12:22 ` Andrew Haley
-- strict thread matches above, loose matches on Subject: below --
2009-11-19 20:48 H. Peter Anvin
2009-11-18 19:30 [patch for 2.6.32? 1/3] hrtimers: remove the "timer_stats_active" check when setting the start info Thomas Gleixner
2009-11-18 20:24 ` [tip:timers/urgent] hrtimer: Fix /proc/timer_list regression tip-bot for Feng Tang
2009-11-19 7:20 ` Ingo Molnar
2009-11-19 10:05 ` Thomas Gleixner
2009-11-19 14:30 ` BUG: function graph tracer function frame assumptions Thomas Gleixner
2009-11-19 15:37 ` BUG: GCC-4.4.x changes the function frame on some functions Thomas Gleixner
2009-11-19 15:44 ` Andrew Haley
2009-11-19 15:54 ` H. Peter Anvin
2009-11-19 15:57 ` Richard Guenther
2009-11-19 16:02 ` Steven Rostedt
2009-11-19 16:11 ` H. Peter Anvin
2009-11-19 16:19 ` Frederic Weisbecker
2009-11-19 16:06 ` Thomas Gleixner
2009-11-19 16:17 ` Andrew Haley
2009-11-19 16:43 ` Thomas Gleixner
2009-11-19 16:12 ` Steven Rostedt
2009-11-19 15:45 ` H. Peter Anvin
2009-11-19 15:49 ` Richard Guenther
2009-11-19 15:52 ` Richard Guenther
2009-11-19 17:37 ` Andi Kleen
2009-11-19 17:39 ` Linus Torvalds
2009-11-19 17:51 ` Thomas Gleixner
2009-11-19 17:59 ` Steven Rostedt
2009-11-19 18:03 ` Richard Guenther
2009-11-19 18:22 ` Andrew Haley
2009-11-19 18:41 ` Linus Torvalds
2009-11-19 18:43 ` Linus Torvalds
2009-11-19 18:54 ` Linus Torvalds
2009-11-19 19:01 ` Thomas Gleixner
2009-11-23 9:16 ` Jakub Jelinek
2009-11-23 9:51 ` Thomas Gleixner
2009-11-19 19:10 ` David Daney
2009-11-19 19:28 ` Steven Rostedt
2009-11-19 19:46 ` Frederic Weisbecker
2009-11-19 19:54 ` Kai Tietz
2009-11-19 20:05 ` Frederic Weisbecker
2009-11-19 20:05 ` Steven Rostedt
2009-11-19 20:17 ` Steven Rostedt
2009-11-19 20:28 ` Frederic Weisbecker
2009-11-19 20:25 ` Frederic Weisbecker
2009-11-19 20:36 ` Linus Torvalds
2009-11-19 20:44 ` Steven Rostedt
2009-11-19 19:50 ` H. Peter Anvin
2009-11-19 20:06 ` Linus Torvalds
2009-11-19 21:12 ` Jeff Law
2009-11-19 20:10 ` Steven Rostedt
2009-11-19 21:05 ` Jeff Law
2009-11-19 18:31 ` Thomas Gleixner
2009-11-19 18:38 ` Linus Torvalds
2009-11-19 18:47 ` Ingo Molnar
2009-11-19 19:06 ` Steven Rostedt
2009-11-19 19:50 ` Ingo Molnar
2009-11-19 20:36 ` Thomas Gleixner
2009-11-19 18:20 ` Andrew Haley
2009-11-19 18:33 ` Steven Rostedt
2009-11-19 18:36 ` Andrew Pinski
2009-11-19 18:36 ` Andrew Haley
2009-11-19 18:37 ` H. Peter Anvin
2009-11-19 18:39 ` Thomas Gleixner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4B05B7AD.20500@redhat.com \
--to=law@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=aph@redhat.com \
--cc=ddaney@caviumnetworks.com \
--cc=feng.tang@intel.com \
--cc=fweisbec@gmail.com \
--cc=gcc@gcc.gnu.org \
--cc=heiko.carstens@de.ibm.com \
--cc=hpa@zytor.com \
--cc=jakub@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=peterz@infradead.org \
--cc=richard.guenther@gmail.com \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox