From: Ingo Molnar <mingo@elte.hu>
To: Peter Waechtler <pwaechtler@mac.com>
Cc: Larry McVoy <lm@bitmover.com>, Bill Davidsen <davidsen@tmr.com>,
<linux-kernel@vger.kernel.org>, ingo Molnar <mingo@redhat.com>
Subject: Re: [ANNOUNCE] Native POSIX Thread Library 0.1
Date: Mon, 23 Sep 2002 22:36:28 +0200 (CEST) [thread overview]
Message-ID: <Pine.LNX.4.44.0209232233250.2343-100000@localhost.localdomain> (raw)
In-Reply-To: <F425930C-CF2E-11D6-8873-00039387C942@mac.com>
On Mon, 23 Sep 2002, Peter Waechtler wrote:
> Getting into kernel is not the same as a context switch. Return EAGAIN
> or EWOULDBLOCK is definetly _not_ causing a context switch.
this is a common misunderstanding. When switching from thread to thread in
the 1:1 model, most of the cost comes from entering/exiting the kernel. So
*once* we are in the kernel the cheapest way is not to piggyback to
userspace to do some userspace context-switch - but to do it right in the
kernel.
in the kernel we can do much higher quality scheduling decisions than in
userspace. SMP affinity, various statistics are right available in
kernel-space - userspace does not have any of that. Not to talk about
preemption.
Ingo
next prev parent reply other threads:[~2002-09-23 20:23 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 [this message]
2002-09-23 21:08 ` Peter Wächtler
2002-09-23 22:44 ` Mark Mielke
2002-09-23 23:01 ` Bill Huey
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
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=Pine.LNX.4.44.0209232233250.2343-100000@localhost.localdomain \
--to=mingo@elte.hu \
--cc=davidsen@tmr.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lm@bitmover.com \
--cc=mingo@redhat.com \
--cc=pwaechtler@mac.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;
as well as URLs for NNTP newsgroup(s).