From: Bill Huey (Hui) <billh@gnuppy.monkey.org>
To: Mark Mielke <mark@mark.mielke.cc>
Cc: Peter W?chtler <pwaechtler@mac.com>, Ingo Molnar <mingo@elte.hu>,
Larry McVoy <lm@bitmover.com>, Bill Davidsen <davidsen@tmr.com>,
linux-kernel@vger.kernel.org,
"Bill Huey (Hui)" <billh@gnuppy.monkey.org>
Subject: Re: [ANNOUNCE] Native POSIX Thread Library 0.1
Date: Mon, 23 Sep 2002 16:01:22 -0700 [thread overview]
Message-ID: <20020923230122.GA3642@gnuppy.monkey.org> (raw)
In-Reply-To: <20020923184423.B26887@mark.mielke.cc>
On Mon, Sep 23, 2002 at 06:44:23PM -0400, Mark Mielke wrote:
> Think of it this way... two threads are blocked on different resources...
> The currently executing thread reaches a point where it blocks.
>
> OS threads:
> 1) thread#1 invokes a system call
> 2) OS switches tasks to thread#2 and returns from blocking
>
> user-space threads:
> 1) thread#1 invokes a system call
> 2) thread#1 returns from system call, EWOULDBLOCK
> 3) thread#1 invokes poll(), select(), ioctl() to determine state
> 4) thread#1 returns from system call
More like the UTS blocks the thread and waits for an IO upcall to notify
the change of state in the kernel. It's equivalent to a single in overhead,
something like a SIGIO, or async IO notification.
Delete 3 and 4. It's certainly much faster than select() and family.
> 5) thread#1 switches stack pointer to be thread#2 upon determination
> that the resource thread#2 was waiting on is ready.
Right, then marks it running and runs it.
> Certainly the above descriptions are not fully accurate, or complete,
> and it is possible that the M:N threading would make a fair compromise
> between OS thread sand user-space threads, however, if user-space threads
> requires all this extra work, and M:N threads requires some extra work,
> some less work, and extra book keeping and system calls, why couldn't
> OS threads by themselves be more efficient?
Crazy synchronization by non-web-server like applications. Who knows. I
personally can't think up really clear example at this time since I don't
do that kind of programming, but I'm sure concurrency experts can...
I'm just not one of those people.
bill
next prev parent reply other threads:[~2002-09-23 22:56 UTC|newest]
Thread overview: 124+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-09-22 18:55 [ANNOUNCE] Native POSIX Thread Library 0.1 Peter Waechtler
2002-09-22 21:32 ` Larry McVoy
2002-09-23 10:05 ` Bill Davidsen
2002-09-23 11:55 ` Peter Waechtler
2002-09-23 19:14 ` Bill Davidsen
2002-09-29 23:26 ` Buddy Lumpkin
2002-09-30 14:54 ` Corey Minyard
2002-09-23 15:30 ` Larry McVoy
2002-09-23 19:44 ` Olivier Galibert
2002-09-23 19:48 ` Bill Davidsen
2002-09-23 20:32 ` Ingo Molnar
2002-09-24 0:03 ` Andy Isaacson
2002-09-24 0:10 ` Jeff Garzik
2002-09-24 0:14 ` Andy Isaacson
2002-09-24 5:53 ` Ingo Molnar
2002-09-24 20:34 ` David Schwartz
2002-09-24 7:12 ` Thunder from the hill
2002-09-24 7:30 ` Ingo Molnar
2002-09-23 22:35 ` Mark Mielke
2002-09-23 19:59 ` Peter Waechtler
2002-09-23 20:36 ` Ingo Molnar
2002-09-23 21:08 ` Peter Wächtler
2002-09-23 22:44 ` Mark Mielke
2002-09-23 23:01 ` Bill Huey [this message]
2002-09-23 23:11 ` Mark Mielke
2002-09-24 0:21 ` Bill Huey
2002-09-24 3:20 ` Mark Mielke
2002-09-23 23:57 ` Andy Isaacson
2002-09-24 6:32 ` 1:1 threading vs. scheduler activations (was: Re: [ANNOUNCE] Native POSIX Thread Library 0.1) Ingo Molnar
2002-09-25 3:08 ` Bill Huey
2002-09-24 18:10 ` [ANNOUNCE] Native POSIX Thread Library 0.1 Christoph Hellwig
2002-09-23 21:32 ` Bill Huey
2002-09-23 21:41 ` dean gaudet
2002-09-23 22:10 ` Bill Huey
2002-09-23 22:56 ` Mark Mielke
2002-09-24 10:02 ` Nikita Danilov
2002-09-23 21:22 ` Bill Huey
2002-09-23 21:03 ` Bill Huey
2002-09-24 12:03 ` Michael Sinz
2002-09-24 13:40 ` Peter Svensson
2002-09-24 14:20 ` Michael Sinz
2002-09-24 14:50 ` Offtopic: (was Re: [ANNOUNCE] Native POSIX Thread Library 0.1) Peter Svensson
2002-09-24 15:19 ` Mark Veltzer
2002-09-24 17:29 ` Rik van Riel
2002-09-25 18:57 ` Mark Mielke
2002-09-25 19:04 ` Rik van Riel
2002-09-25 19:29 ` Mark Veltzer
2002-09-25 19:23 ` Rik van Riel
2002-09-24 16:31 ` Rik van Riel
2002-09-24 18:49 ` Michael Sinz
2002-09-24 19:12 ` PATCH: per user fair scheduler 2.4.19 (cleaned up, thanks hch) (was: Re: Offtopic: (was Re: [ANNOUNCE] Native POSIX Thread Library 0.1)) Rik van Riel
2002-09-24 20:19 ` [ANNOUNCE] Native POSIX Thread Library 0.1 David Schwartz
2002-09-24 21:10 ` Chris Friesen
2002-09-24 21:22 ` Rik van Riel
2002-09-24 21:35 ` Roberto Peon
2002-09-24 21:35 ` Chris Friesen
2002-09-25 19:02 ` David Schwartz
2002-09-24 23:16 ` Peter Waechtler
2002-09-24 23:23 ` Rik van Riel
2002-09-25 19:05 ` David Schwartz
[not found] <987738530@toto.iv>
2002-09-24 2:48 ` Peter Chubb
2002-09-24 3:37 ` Mark Mielke
-- strict thread matches above, loose matches on Subject: below --
2002-09-23 16:36 Matthias Urlichs
2002-09-20 7:46 Joerg Pommnitz
2002-09-20 0:41 Ulrich Drepper
2002-09-20 0:51 ` William Lee Irwin III
2002-09-20 1:35 ` Ulrich Drepper
2002-09-20 1:42 ` William Lee Irwin III
2002-09-20 1:56 ` Larry McVoy
2002-09-20 2:01 ` Rik van Riel
2002-09-20 2:15 ` Benjamin LaHaise
2002-09-20 2:40 ` Dave Hansen
2002-09-20 2:47 ` William Lee Irwin III
2002-09-20 2:17 ` Larry McVoy
2002-09-20 2:24 ` Rik van Riel
2002-09-20 2:32 ` Ulrich Drepper
2002-09-20 6:01 ` Linus Torvalds
2002-09-20 8:02 ` Ingo Molnar
2002-09-20 2:23 ` Anton Blanchard
2002-09-20 9:53 ` Padraig Brady
2002-09-20 13:28 ` Robert Love
2002-09-20 16:01 ` Bill Davidsen
2002-09-20 9:54 ` Adrian Bunk
2002-09-20 10:53 ` Ingo Molnar
2002-09-20 19:04 ` Ulrich Drepper
2002-09-20 23:06 ` J.A. Magallon
2002-09-20 23:33 ` Ulrich Drepper
2002-09-20 23:42 ` J.A. Magallon
2002-09-20 10:20 ` Bill Huey
2002-09-20 10:47 ` Ingo Molnar
2002-09-20 12:06 ` Bill Huey
2002-09-20 16:20 ` Ingo Molnar
2002-09-20 21:50 ` Bill Huey
2002-09-20 22:30 ` dean gaudet
2002-09-20 23:11 ` Bill Huey
2002-09-21 3:38 ` dean gaudet
2002-09-21 4:01 ` Bill Huey
2002-09-21 5:06 ` Ingo Molnar
2002-09-20 23:45 ` Bill Huey
2002-09-21 4:58 ` Ingo Molnar
2002-09-22 2:51 ` Bill Huey
2002-09-21 4:48 ` Ingo Molnar
2002-09-22 1:38 ` Bill Huey
2002-09-22 13:38 ` Bill Davidsen
2002-09-22 18:41 ` Eric W. Biederman
2002-09-22 22:13 ` dean gaudet
2002-09-26 17:21 ` Alan Cox
2002-09-23 0:11 ` Bill Huey
2002-09-24 16:07 ` Eric W. Biederman
2002-09-24 23:21 ` Bill Huey
2002-09-25 3:06 ` Eric W. Biederman
2002-09-23 21:12 ` Bill Huey
2002-09-20 10:35 ` Luca Barbieri
2002-09-20 11:19 ` Ingo Molnar
2002-09-20 18:40 ` Roland McGrath
2002-09-20 21:21 ` Luca Barbieri
2002-09-20 12:37 ` jlnance
2002-09-20 16:42 ` Ingo Molnar
2002-09-24 0:40 ` Rusty Russell
2002-09-24 5:47 ` Ingo Molnar
2002-09-24 6:15 ` Rusty Russell
2002-09-20 15:43 ` Bill Davidsen
2002-09-20 16:15 ` Jakub Jelinek
2002-09-20 17:16 ` Bill Davidsen
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