From: Ingo Molnar <mingo@elte.hu>
To: Rik van Riel <riel@conectiva.com.br>
Cc: Ulrich Drepper <drepper@redhat.com>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: 100,000 threads? [was: [ANNOUNCE] Native POSIX Thread Library 0.1]
Date: Fri, 20 Sep 2002 09:52:39 +0200 (CEST) [thread overview]
Message-ID: <Pine.LNX.4.44.0209200942030.27825-100000@localhost.localdomain> (raw)
In-Reply-To: <Pine.LNX.4.44L.0209192258010.1857-100000@imladris.surriel.com>
On Thu, 19 Sep 2002, Rik van Riel wrote:
> So, where did you put those 800 MB of kernel stacks needed for 100,000
> threads ?
With the default split and kernel stack we can start up 94,000 threads on
x86. With Ben's/Dave's patch we can have up to 188,000 threads. With a 2:2
GB VM split configured we can start 376,000 threads. If someone's that
desperate then with a 1:3 split we can start up 564,000 threads.
Anton tested 1 million concurrent threads on one of his bigger PowerPC
boxes, which started up in around 30 seconds. I think he saw a load
average of around 200 thousand. [ie. the runqueue was probably a few
hundred thousand entries long at times.]
> If you used the standard 3:1 user/kernel split you'd be using all of
> ZONE_NORMAL for kernel stacks, but if you use a 2:2 split you'll end up
> with a lot less user space (bad if you want to have many threads in the
> same address space).
the extreme high-end of threading typically uses very controlled
applications and very small user level stacks.
as to the question of why so many threads, the answer is because we can :)
This, besides demonstrating some of the recent scalability advances, gives
us the warm fuzzy feeling that things are right in this area. I mean,
there are architectures where Linux could map a petabyte of RAM just fine,
even though that might not be something we desperately need today.
Ingo
next prev parent reply other threads:[~2002-09-20 7:40 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-09-20 0:41 [ANNOUNCE] Native POSIX Thread Library 0.1 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 7:52 ` Ingo Molnar [this message]
2002-09-20 15:47 ` 100,000 threads? [was: [ANNOUNCE] Native POSIX Thread Library 0.1] Bill Davidsen
2002-09-20 9:53 ` [ANNOUNCE] Native POSIX Thread Library 0.1 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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