From: Daniel Borkmann <daniel@iogearbox.net>
To: Denys Vlasenko <dvlasenk@redhat.com>,
Ingo Molnar <mingo@kernel.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Jason Low <jason.low2@hp.com>,
Peter Zijlstra <peterz@infradead.org>,
Davidlohr Bueso <dave@stgolabs.net>,
Tim Chen <tim.c.chen@linux.intel.com>,
Aswin Chandramouleeswaran <aswin@hp.com>,
LKML <linux-kernel@vger.kernel.org>,
Borislav Petkov <bp@alien8.de>,
Andy Lutomirski <luto@amacapital.net>,
Brian Gerst <brgerst@gmail.com>, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [PATCH] x86: Align jump targets to 1 byte boundaries
Date: Fri, 10 Apr 2015 21:23:19 +0200 [thread overview]
Message-ID: <55282327.6070607@iogearbox.net> (raw)
In-Reply-To: <5527C700.3030405@redhat.com>
On 04/10/2015 02:50 PM, Denys Vlasenko wrote:
...
> New-ish versions of gcc allow people to specify optimization
> options per function:
>
> https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function-Attributes
>
> optimize
> The optimize attribute is used to specify that a function is to be compiled
> with different optimization options than specified on the command line.
> Arguments can either be numbers or strings. Numbers are assumed to be an
> optimization level. Strings that begin with O are assumed to be an
> optimization option, while other options are assumed to be used with
> a -f prefix.
>
> How about not aligning code by default, and using
>
> #define hot_func __attribute__((optimize("O2","align-functions=16","align-jumps=16")))
I stumbled over that some time ago in a different context. Apparently,
that's being considered broken by gcc folks [1]. ;)
[1] http://gcc.gnu.org/ml/gcc/2012-07/msg00211.html
next prev parent reply other threads:[~2015-04-10 19:23 UTC|newest]
Thread overview: 108+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-08 19:39 [PATCH 0/2] locking: Simplify mutex and rwsem spinning code Jason Low
2015-04-08 19:39 ` [PATCH 1/2] locking/mutex: Further refactor mutex_spin_on_owner() Jason Low
2015-04-09 9:00 ` [tip:locking/core] locking/mutex: Further simplify mutex_spin_on_owner() tip-bot for Jason Low
2015-04-08 19:39 ` [PATCH 2/2] locking/rwsem: Use a return variable in rwsem_spin_on_owner() Jason Low
2015-04-09 5:37 ` Ingo Molnar
2015-04-09 6:40 ` Jason Low
2015-04-09 7:53 ` Ingo Molnar
2015-04-09 16:47 ` Linus Torvalds
2015-04-09 17:56 ` Paul E. McKenney
2015-04-09 18:08 ` Linus Torvalds
2015-04-09 18:16 ` Linus Torvalds
2015-04-09 18:39 ` Paul E. McKenney
2015-04-10 9:00 ` [PATCH] mutex: Speed up mutex_spin_on_owner() by not taking the RCU lock Ingo Molnar
2015-04-10 9:12 ` Ingo Molnar
2015-04-10 9:21 ` [PATCH] uaccess: Add __copy_from_kernel_inatomic() primitive Ingo Molnar
2015-04-10 11:14 ` [PATCH] x86/uaccess: Implement get_kernel() Ingo Molnar
2015-04-10 11:27 ` [PATCH] mutex: Improve mutex_spin_on_owner() code generation Ingo Molnar
2015-04-10 12:08 ` [PATCH] x86: Align jump targets to 1 byte boundaries Ingo Molnar
2015-04-10 12:18 ` [PATCH] x86: Pack function addresses tightly as well Ingo Molnar
2015-04-10 12:30 ` [PATCH] x86: Pack loops " Ingo Molnar
2015-04-10 13:46 ` Borislav Petkov
2015-05-15 9:40 ` [tip:x86/asm] " tip-bot for Ingo Molnar
2015-05-17 6:03 ` [tip:x86/apic] " tip-bot for Ingo Molnar
2015-05-15 9:39 ` [tip:x86/asm] x86: Pack function addresses " tip-bot for Ingo Molnar
2015-05-15 18:36 ` Linus Torvalds
2015-05-15 20:52 ` Denys Vlasenko
2015-05-17 5:58 ` Ingo Molnar
2015-05-17 7:09 ` Ingo Molnar
2015-05-17 7:30 ` Ingo Molnar
2015-05-18 9:28 ` Denys Vlasenko
2015-05-19 21:38 ` [RFC PATCH] x86/64: Optimize the effective instruction cache footprint of kernel functions Ingo Molnar
2015-05-20 0:47 ` Linus Torvalds
2015-05-20 12:21 ` Denys Vlasenko
2015-05-21 11:36 ` Ingo Molnar
2015-05-21 11:38 ` Denys Vlasenko
2016-04-16 21:08 ` Denys Vlasenko
2015-05-20 13:09 ` Ingo Molnar
2015-05-20 11:29 ` Denys Vlasenko
2015-05-21 13:28 ` Ingo Molnar
2015-05-21 14:03 ` Ingo Molnar
2015-04-10 12:50 ` [PATCH] x86: Align jump targets to 1 byte boundaries Denys Vlasenko
2015-04-10 13:18 ` H. Peter Anvin
2015-04-10 17:54 ` Ingo Molnar
2015-04-10 18:32 ` H. Peter Anvin
2015-04-11 14:41 ` Markus Trippelsdorf
2015-04-12 10:14 ` Ingo Molnar
2015-04-13 16:23 ` Markus Trippelsdorf
2015-04-13 17:26 ` Markus Trippelsdorf
2015-04-13 18:31 ` Linus Torvalds
2015-04-13 19:09 ` Markus Trippelsdorf
2015-04-14 5:38 ` Ingo Molnar
2015-04-14 8:23 ` Markus Trippelsdorf
2015-04-14 9:16 ` Ingo Molnar
2015-04-14 11:17 ` Markus Trippelsdorf
2015-04-14 12:09 ` Ingo Molnar
2015-04-10 18:48 ` Linus Torvalds
2015-04-12 23:44 ` Maciej W. Rozycki
2015-04-10 19:23 ` Daniel Borkmann [this message]
2015-04-11 13:48 ` Markus Trippelsdorf
2015-04-10 13:19 ` Borislav Petkov
2015-04-10 13:54 ` Denys Vlasenko
2015-04-10 14:01 ` Borislav Petkov
2015-04-10 14:53 ` Denys Vlasenko
2015-04-10 15:25 ` Borislav Petkov
2015-04-10 15:48 ` Denys Vlasenko
2015-04-10 15:54 ` Borislav Petkov
2015-04-10 21:44 ` Borislav Petkov
2015-04-10 18:54 ` Linus Torvalds
2015-04-10 14:10 ` Paul E. McKenney
2015-04-11 14:28 ` Josh Triplett
2015-04-11 9:20 ` [PATCH] x86: Turn off GCC branch probability heuristics Ingo Molnar
2015-04-11 17:41 ` Linus Torvalds
2015-04-11 18:57 ` Thomas Gleixner
2015-04-11 19:35 ` Linus Torvalds
2015-04-12 5:47 ` Ingo Molnar
2015-04-12 6:20 ` Markus Trippelsdorf
2015-04-12 10:15 ` Ingo Molnar
2015-04-12 7:56 ` Mike Galbraith
2015-04-12 7:41 ` Ingo Molnar
2015-04-12 8:07 ` Ingo Molnar
2015-04-12 21:11 ` Jan Hubicka
2015-05-14 11:59 ` [PATCH] x86: Align jump targets to 1 byte boundaries Denys Vlasenko
2015-05-14 18:17 ` Ingo Molnar
2015-05-14 19:04 ` Denys Vlasenko
2015-05-14 19:44 ` Ingo Molnar
2015-05-15 15:45 ` Josh Triplett
2015-05-17 5:34 ` Ingo Molnar
2015-05-17 19:18 ` Josh Triplett
2015-05-18 6:48 ` Ingo Molnar
2015-05-15 9:39 ` [tip:x86/asm] x86: Align jump targets to 1-byte boundaries tip-bot for Ingo Molnar
2015-04-10 11:34 ` [PATCH] x86/uaccess: Implement get_kernel() Peter Zijlstra
2015-04-10 18:04 ` Ingo Molnar
2015-04-10 17:49 ` Linus Torvalds
2015-04-10 18:04 ` Ingo Molnar
2015-04-10 18:09 ` Linus Torvalds
2015-04-10 14:20 ` [PATCH] mutex: Speed up mutex_spin_on_owner() by not taking the RCU lock Paul E. McKenney
2015-04-10 17:44 ` Ingo Molnar
2015-04-10 18:05 ` Paul E. McKenney
2015-04-09 19:43 ` [PATCH 2/2] locking/rwsem: Use a return variable in rwsem_spin_on_owner() Jason Low
2015-04-09 19:58 ` Paul E. McKenney
2015-04-09 20:58 ` Jason Low
2015-04-09 21:07 ` Paul E. McKenney
2015-04-09 19:59 ` Davidlohr Bueso
2015-04-09 20:36 ` Jason Low
2015-04-10 2:43 ` Andev
2015-04-10 9:04 ` Ingo Molnar
2015-04-08 19:49 ` [PATCH 0/2] locking: Simplify mutex and rwsem spinning code Davidlohr Bueso
2015-04-08 20:10 ` Jason Low
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=55282327.6070607@iogearbox.net \
--to=daniel@iogearbox.net \
--cc=a.p.zijlstra@chello.nl \
--cc=aswin@hp.com \
--cc=bp@alien8.de \
--cc=brgerst@gmail.com \
--cc=dave@stgolabs.net \
--cc=dvlasenk@redhat.com \
--cc=hpa@zytor.com \
--cc=jason.low2@hp.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=mingo@kernel.org \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=tim.c.chen@linux.intel.com \
--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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.