public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Jakub Jelinek <jakub@redhat.com>
To: Pierre Peiffer <pierre.peiffer@bull.net>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Dinakar Guniguntala <dino@in.ibm.com>,
	Jean-Pierre Dion <jean-pierre.dion@bull.net>,
	Ingo Molnar <mingo@elte.hu>, Ulrich Drepper <drepper@redhat.com>,
	Darren Hart <dvhltc@us.ibm.com>
Subject: Re: [PATCH 2.6.20-rc4 4/4][RFC] sys_futex64 : allows 64bit futexes
Date: Thu, 11 Jan 2007 17:14:46 -0500	[thread overview]
Message-ID: <20070111221446.GF29911@devserv.devel.redhat.com> (raw)
In-Reply-To: <45A3C1F6.4020503@bull.net>

On Tue, Jan 09, 2007 at 05:25:26PM +0100, Pierre Peiffer wrote:
> This latest patch is an adaptation of the sys_futex64 syscall provided in 
> -rt
> patch (originally written by Ingo). It allows the use of 64bit futex.
> 
> I have re-worked most of the code to avoid the duplication of the code.
> 
> It does not provide the functionality for all architectures, and thus, it 
> can
> not be applied "as is".
> But, again, feedbacks and comments are welcome.

Why do you support all operations for 64-bit futexes?
IMHO PI futexes don't make sense for 64-bit futexes, PI futexes have
hardcoded bit layout of the 32-bit word.  Similarly, FUTEX_WAKE
is not really necessary for 64-bit futexes, 32-bit futex's FUTEX_WAKE
can wake it equally well (it never reads anything, all it cares
is about the futex's address).  Similarly, I don't see a need for
FUTEX_WAKE_OP (and this could simplify the patch quite a lot, no
need to change asm*/futex.h headers at all).
All that's needed is 64-bit FUTEX_WAIT and perhaps FUTEX_CMP_REQUEUE.

	Jakub

      parent reply	other threads:[~2007-01-11 22:16 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <45A3B330.9000104@bull.net>
2007-01-09 16:16 ` [PATCH 2.6.20-rc4 1/4] futex priority based wakeup Pierre Peiffer
2007-01-09 16:29   ` Ulrich Drepper
2007-01-10 11:47     ` Pierre Peiffer
2007-01-10 12:03       ` Pierre Peiffer
2007-01-10 12:54       ` Jakub Jelinek
2007-01-10 15:05         ` Pierre Peiffer
2007-01-10 18:15           ` Ulrich Drepper
2007-01-11  7:20       ` Ulrich Drepper
2007-01-09 17:59   ` Daniel Walker
2007-01-10 16:11   ` Daniel Walker
2007-01-10 16:29     ` Pierre Peiffer
2007-01-10 16:33       ` Daniel Walker
2007-01-09 16:16 ` [PATCH 2.6.20-rc4 2/4] Make futex_wait() use an hrtimer for timeout Pierre Peiffer
2007-01-09 16:20 ` [PATCH 2.6.20-rc4 3/4] futex_requeue_pi optimization Pierre Peiffer
2007-01-09 16:33   ` Ulrich Drepper
2007-01-10  8:17     ` Pierre Peiffer
2007-01-10  8:24       ` Ulrich Drepper
2007-01-09 16:25 ` [PATCH 2.6.20-rc4 4/4][RFC] sys_futex64 : allows 64bit futexes Pierre Peiffer
2007-01-11 21:49   ` Andrew Morton
2007-01-11 22:14   ` Jakub Jelinek [this message]

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=20070111221446.GF29911@devserv.devel.redhat.com \
    --to=jakub@redhat.com \
    --cc=dino@in.ibm.com \
    --cc=drepper@redhat.com \
    --cc=dvhltc@us.ibm.com \
    --cc=jean-pierre.dion@bull.net \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=pierre.peiffer@bull.net \
    /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