From: "Hubertus Franke" <frankeh@us.ibm.com>
To: bert hubert <ahu@ds9a.nl>
Cc: linux-kernel@vger.kernel.org
Subject: Re: threading question
Date: Wed, 13 Jun 2001 15:05:49 -0400 [thread overview]
Message-ID: <OF8B8E165A.F0F1217D-ON85256A6A.0068B1CA@pok.ibm.com> (raw)
>I got that response too. When I pressed kernel people for details it turns
>out that they think having hundreds of runnable threads/processes (mostly
>the same thing under Linux) is wasteful. The scheduler is just not
optimised
>for that.
Try out the http://lse.sourceforge.net/scheduling patches. The MQ kernel
scheduler sure can handle this
kind of load :-)
Hubertus Franke
Enterprise Linux Group (Mgr), Linux Technology Center (Member Scalability)
, OS-PIC (Chair)
email: frankeh@us.ibm.com
(w) 914-945-2003 (fax) 914-945-4425 TL: 862-2003
bert hubert <ahu@ds9a.nl>@vger.kernel.org on 06/13/2001 01:31:39 PM
Sent by: linux-kernel-owner@vger.kernel.org
To: linux-kernel@vger.kernel.org
cc:
Subject: Re: threading question
On Tue, Jun 12, 2001 at 12:06:40PM -0700, Kip Macy wrote:
> This may sound like flamebait, but its not. Linux threads are basically
> just processes that share the same address space. Their performance is
> measurably worse than it is on most commercial Unixes and FreeBSD.
Thread creation may be a bit slow. But the kludges to provide posix threads
completely from userspace also hurt. Notably, they do not scale over
multiple CPUs.
> They are not, or at least two years ago, were not POSIX compliant
> (they behaved badly with respect to signals). The impoverished
POSIX threads are silly with respect to signals. I do almost all my
programming these days with pthreads and I find that I really do not miss
signals at all.
> from Larry McVoy's home page attributed to Alan Cox illustrates this
> reasonably well: "A computer is a state machine. Threads are for people
> who can't program state machines." Sorry for not being more helpful.
I got that response too. When I pressed kernel people for details it turns
out that they think having hundreds of runnable threads/processes (mostly
the same thing under Linux) is wasteful. The scheduler is just not
optimised
for that.
Regards,
bert
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next reply other threads:[~2001-06-13 19:05 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-06-13 19:05 Hubertus Franke [this message]
[not found] <fa.f6da6av.agod3u@ifi.uio.no>
[not found] ` <fa.e54jbkv.kg4r99@ifi.uio.no>
2001-06-16 22:22 ` threading question Dan Maas
-- strict thread matches above, loose matches on Subject: below --
2001-06-12 18:24 ognen
2001-06-12 18:39 ` Davide Libenzi
2001-06-12 18:58 ` Christoph Hellwig
2001-06-12 19:07 ` ognen
2001-06-12 19:15 ` Kip Macy
2001-06-12 19:29 ` Christoph Hellwig
2001-06-12 19:15 ` Christoph Hellwig
2001-06-13 12:20 ` Kurt Garloff
2001-06-13 13:35 ` J . A . Magallon
2001-06-13 14:17 ` Philips
2001-06-13 15:06 ` ognen
2001-06-12 21:44 ` Davide Libenzi
2001-06-12 21:48 ` ognen
2001-06-14 18:15 ` Alan Cox
2001-06-12 21:58 ` Albert D. Cahalan
2001-06-12 23:48 ` J . A . Magallon
2001-06-12 19:06 ` Kip Macy
2001-06-12 19:14 ` Alexander Viro
2001-06-12 19:25 ` Russell Leighton
2001-06-12 23:27 ` Mike Castle
2001-06-13 17:31 ` bert hubert
2001-06-14 6:45 ` Helge Hafting
2001-06-14 18:28 ` Alan Cox
2001-06-14 19:01 ` bert hubert
2001-06-14 19:22 ` Russell Leighton
2001-06-15 11:29 ` Anil Kumar
2001-06-14 23:05 ` J . A . Magallon
2001-06-16 14:16 ` Michael Rothwell
2001-06-16 15:19 ` Alan Cox
2001-06-16 18:33 ` Russell Leighton
2001-06-16 19:06 ` Michael Rothwell
2001-06-12 22:41 ` Pavel Machek
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