linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
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

--
http://www.PowerDNS.com      Versatile DNS Services
Trilab                       The Technology People
'SYN! .. SYN|ACK! .. ACK!' - the mating call of the internet
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/




             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

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=OF8B8E165A.F0F1217D-ON85256A6A.0068B1CA@pok.ibm.com \
    --to=frankeh@us.ibm.com \
    --cc=ahu@ds9a.nl \
    --cc=linux-kernel@vger.kernel.org \
    /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).