From: Rusty Russell <rusty@rustcorp.com.au>
To: Linus Torvalds <torvalds@transmeta.com>
To: "Peter Wächtler" <pwaechtler@loewe-komp.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>,
linux-kernel@vger.kernel.org, frankeh@watson.ibm.com
Subject: Re: [PATCH] Futex Asynchronous Interface
Date: Thu, 13 Jun 2002 12:57:51 +1000 [thread overview]
Message-ID: <E17IKo3-000341-00@wagner.rustcorp.com.au> (raw)
In-Reply-To: Your message of "Wed, 12 Jun 2002 09:52:28 MST." <Pine.LNX.4.44.0206120946100.22189-100000@home.transmeta.com>
In message <Pine.LNX.4.44.0206120946100.22189-100000@home.transmeta.com> you wr
ite:
>
>
>
> On Wed, 12 Jun 2002, Peter W=E4chtler wrote:
> >
> > For the uncontended case: their is no blocked process...
>
> Wrong.
>
> The process that holds the lock can die _before_ it gets contended.
>
> When another thread comes in, it now is contended, but the kernel doesn't
> know about anything.
Note also: this is a feature.
I have a little helper program which can grab or release a futex in a
(mmapped) file. It's great for shell scripts to grab locks. In this
case the helper exits with the lock held, and a later invocation
releases a lock it never held.
*AND* the lock is persistent across reboots, since it's in a file.
How cool is that!
This is the *third* major thread on this subject, BTW.
Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
next prev parent reply other threads:[~2002-06-13 2:53 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-06-06 7:26 Rusty Russell
2002-06-02 0:10 ` Pavel Machek
2002-06-10 6:57 ` Rusty Russell
2002-06-06 16:36 ` Linus Torvalds
2002-06-06 19:27 ` Alan Cox
2002-06-06 23:21 ` Rusty Russell
2002-06-07 8:33 ` Peter Wächtler
2002-06-08 22:28 ` Linus Torvalds
2002-06-09 9:49 ` Kai Henningsen
2002-06-09 18:09 ` Linus Torvalds
2002-06-09 19:06 ` Thunder from the hill
2002-06-10 6:39 ` Kai Henningsen
2002-06-10 7:55 ` Helge Hafting
2002-06-10 14:10 ` Thunder from the hill
2002-06-10 20:46 ` Kai Henningsen
2002-06-11 14:14 ` john slee
2002-06-10 15:11 ` Linus Torvalds
2002-06-11 15:06 ` Eric W. Biederman
2002-06-10 20:57 ` H. Peter Anvin
2002-06-09 10:07 ` Peter Wächtler
2002-06-09 17:49 ` Linus Torvalds
2002-06-07 9:06 ` Rusty Russell
2002-06-08 22:42 ` Linus Torvalds
2002-06-11 9:15 ` Rusty Russell
2002-06-11 16:53 ` Linus Torvalds
2002-06-12 5:32 ` Rusty Russell
2002-06-12 9:16 ` Peter Wächtler
2002-06-12 14:19 ` Hubertus Franke
2002-06-12 16:50 ` Peter Wächtler
2002-06-12 18:15 ` Vladimir Zidar
2002-06-12 15:39 ` Linus Torvalds
2002-06-12 16:29 ` Peter Wächtler
2002-06-12 16:52 ` Linus Torvalds
2002-06-12 17:07 ` Peter Wächtler
2002-06-12 18:32 ` Saurabh Desai
2002-06-12 20:05 ` Oliver Xymoron
2002-06-12 20:16 ` Linus Torvalds
2002-06-13 2:57 ` Rusty Russell [this message]
2002-06-13 9:37 ` Peter Wächtler
2002-06-13 9:55 ` Rusty Russell
2002-06-13 16:38 ` Gabriel Paubert
2002-06-13 16:40 ` Linus Torvalds
2002-06-13 1:32 ` Rusty Russell
2002-06-06 16:08 Martin Wirth
2002-06-06 22:59 ` Rusty Russell
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=E17IKo3-000341-00@wagner.rustcorp.com.au \
--to=rusty@rustcorp.com.au \
--cc=frankeh@watson.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@transmeta.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
all inboxes | Powered by JetHome®