From: Davide Libenzi <davidel@xmailserver.org>
To: Christoph Hellwig <hch@ns.caldera.de>
Cc: linux-kernel@vger.kernel.org, ognen@gene.pbi.nrc.ca
Subject: Re: threading question
Date: Tue, 12 Jun 2001 14:44:49 -0700 (PDT) [thread overview]
Message-ID: <XFMail.20010612144449.davidel@xmailserver.org> (raw)
In-Reply-To: <200106121858.f5CIwmX05650@ns.caldera.de>
On 12-Jun-2001 Christoph Hellwig wrote:
> In article <Pine.LNX.4.30.0106121213570.24593-100000@gene.pbi.nrc.ca> you
> wrote:
>> On dual-CPU machines the speedups are as follows: my version
>> is 1.88 faster than the sequential one on IRIX, 1.81 times on Solaris,
>> 1.8 times on OSF/1, 1.43 times on Linux 2.2.x and 1.52 times on Linux 2.4
>> kernel. Why are the numbers on Linux machines so much lower?
>
> Does your measurement include the time needed to actually create the
> threads or do you even frequently create and destroy threads?
This is an extract of the most busy vmstat report running under his tool :
12 0 0 15508 40980 24880 355480 0 0 0 0 141 481 100 0 0
19 0 0 15508 40248 24880 355480 0 0 0 0 142 564 100 0 0
12 0 0 15508 40112 24880 355480 0 0 0 0 150 543 100 0 0
11 0 0 15508 41272 24880 355480 0 0 0 0 156 594 99 1 0
17 0 0 15508 40408 24880 355480 0 0 0 0 156 474 99 1 0
17 0 0 15508 39840 24880 355480 0 0 0 0 135 475 100 0 0
21 0 0 15508 39568 24880 355480 0 0 0 0 125 409 100 0 0
21 0 0 15508 39668 24880 355480 0 0 0 0 135 420 100 0 0
16 0 0 15508 39760 24880 355480 0 0 0 0 149 486 100 0 0
The context switch is very low and the user CPU utilization is 100% , I don't
think it's system responsibility here ( clearly a CPU bound program ).
Even if the runqueue is long, the context switch is low.
I've just close to me a dual PIII 1GHz workstation that run an MTA that uses
linux pthreads with context switching ranging between 5000 and 11000 with a
thread creation rate of about 300 thread/sec ( relaying 600000 msg/hour ).
No problem at all with the system even if the load avg is a bit high
( about 8 ).
- Davide
next prev parent reply other threads:[~2001-06-12 21:42 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-06-12 18:24 threading question ognen
2001-06-12 18:39 ` Davide Libenzi
2001-06-12 18:57 ` from dmesg: kernel BUG at inode.c:486 Olivier Sessink
2001-06-12 18:58 ` threading question 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 [this message]
2001-06-12 21:48 ` ognen
2001-06-14 18:15 ` Alan Cox
2001-06-14 22:42 ` threading question (results after thread pooling) ognen
2001-06-14 23:00 ` Mike Castle
2001-06-12 21:58 ` threading question 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
2001-06-16 21:30 ` Coroutines [was Re: threading question] Russell Leighton
2001-06-12 22:41 ` threading question Pavel Machek
2001-06-13 19:05 Hubertus Franke
[not found] <fa.f6da6av.agod3u@ifi.uio.no>
[not found] ` <fa.e54jbkv.kg4r99@ifi.uio.no>
2001-06-16 22:22 ` Dan Maas
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=XFMail.20010612144449.davidel@xmailserver.org \
--to=davidel@xmailserver.org \
--cc=hch@ns.caldera.de \
--cc=linux-kernel@vger.kernel.org \
--cc=ognen@gene.pbi.nrc.ca \
/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).