From: Chris Friesen <chris.friesen@genband.com>
To: George Porter <gmporter@cs.ucsd.edu>
Cc: linux-kernel@vger.kernel.org
Subject: Re: read() syscall slowing down due to other threads?
Date: Wed, 02 May 2012 12:39:38 -0600 [thread overview]
Message-ID: <4FA17F6A.9000606@genband.com> (raw)
In-Reply-To: <CANkdjvZinRvHYPKLCFsd6z3FXgM4ScS1Ar9OjO3s1SLDFnridw@mail.gmail.com>
On 05/01/2012 12:03 AM, George Porter wrote:
> However, if I start doing more computation on those other threads, the
> read() syscalls take longer to read the same amount of data,
> eventually slowing down to 50 MBps (50% slower). I've used
> setaffinity() to isolate the Reader threads to one set of cores, and
> the compute threads to a different set of cores, and so I don't think
> it is CPU/scheduling interference.
>
> Thoughts? Has anyone run into this before?
If you're using hyperthreading you may want to try it with either
putting the computation threads on the siblings of the cpus for the
reader threads (to share cache) or else not on the siblings of the cpus
for the reader threads (to minimize contention of cpu resources).
Similarly, you may want to play with wither or not the threads are on
the same or different sockets.
Chris
--
Chris Friesen
Software Developer
GENBAND
chris.friesen@genband.com
www.genband.com
next prev parent reply other threads:[~2012-05-02 18:39 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-01 6:03 read() syscall slowing down due to other threads? George Porter
2012-05-01 6:40 ` Nick Piggin
2012-05-01 12:47 ` George Porter
2012-05-02 18:39 ` Chris Friesen [this message]
2012-05-15 21:08 ` George Porter
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=4FA17F6A.9000606@genband.com \
--to=chris.friesen@genband.com \
--cc=gmporter@cs.ucsd.edu \
--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