public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Rusty Russell <rusty@rustcorp.com.au>
To: Jakub Jelinek <jakub@redhat.com>
Cc: lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>,
	mingo@redhat.com, Andrew Morton <akpm@osdl.org>
Subject: Re: [PATCH] Add FUTEX_CMP_REQUEUE futex op
Date: Sat, 29 May 2004 13:13:25 +1000	[thread overview]
Message-ID: <1085635370.9356.13.camel@bach> (raw)
In-Reply-To: <20040520093817.GX30909@devserv.devel.redhat.com>

On Thu, 2004-05-20 at 19:38, Jakub Jelinek wrote:
> Hi!
> 
> FUTEX_REQUEUE operation has been added to the kernel mainly to improve
> pthread_cond_broadcast which previously used FUTEX_WAKE INT_MAX op.

For the record, I wasn't happy about adding FUTEX_REQUEUE to optimize
for suboptimal apps using the horrid pthreads interface, but I
understand the benchmarking realities.

I'm certainly way less than thrilled to discover that it doesn't work,
and we need to implement FUTEX_CMP_REQUEUE, and of course can't get rid
of FUTEX_REQUEUE.

The base futex concept and interface is simple (although the
implementation w/ the Linux mm subsystem proved interesting in the
corner cases); it's increasingly becoming a horror with these kind of
hacks.

8(
Rusty.
-- 
Anyone who quotes me in their signature is an idiot -- Rusty Russell


  parent reply	other threads:[~2004-05-29  3:13 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-05-20  9:38 [PATCH] Add FUTEX_CMP_REQUEUE futex op Jakub Jelinek
2004-05-20 22:52 ` Andrew Morton
2004-05-21  6:06   ` Ulrich Drepper
2004-05-21  6:36     ` Andrew Morton
2004-05-21  7:15       ` Ulrich Drepper
2004-05-21  7:43       ` Jakub Jelinek
2004-05-22 16:58         ` Arnd Bergmann
2004-05-24  7:34           ` Jakub Jelinek
2004-05-24  8:12             ` Andrew Morton
2004-05-24  8:19               ` Jakub Jelinek
2004-05-28 13:09                 ` DOCUMENTATION " bert hubert
2004-05-28 14:02                   ` Jakub Jelinek
2004-05-28 15:39                     ` bert hubert
2004-05-24  8:27               ` bert hubert
2004-05-24 17:34             ` Arnd Bergmann
2004-05-21  7:05   ` Ingo Molnar
2004-05-21 23:05 ` Andrew Morton
2004-05-22 10:10   ` Ingo Oeser
2004-05-23 17:33   ` Jakub Jelinek
2004-05-29  3:13 ` Rusty Russell [this message]
  -- strict thread matches above, loose matches on Subject: below --
2004-06-07 16:03 Martin Schwidefsky
     [not found] <mailman.1086629984.12568.linux-kernel2news@redhat.com>
2004-06-09 20:04 ` Pete Zaitcev
2004-06-09 22:08   ` Arnd Bergmann
2004-06-11  8:35   ` Martin Schwidefsky

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=1085635370.9356.13.camel@bach \
    --to=rusty@rustcorp.com.au \
    --cc=akpm@osdl.org \
    --cc=jakub@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    /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