From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
To: "Yogi A. Patel" <yapatel@gatech.edu>,
"xenomai@xenomai.org" <xenomai@xenomai.org>
Subject: Re: [Xenomai] Low-latency desktop setting
Date: Thu, 28 Aug 2014 22:02:15 +0200 [thread overview]
Message-ID: <53FF8AC7.5090301@xenomai.org> (raw)
In-Reply-To: <B77BA3CE-F753-4865-A2AD-37EE4888E465@gatech.edu>
On 08/28/2014 09:49 PM, Yogi A. Patel wrote:
> In configuring the kernel (after patching with xenomai), there is an
> option to change the preemption model to "low-latency desktop".
>
> Is this a setting that should be set? Or should it be left to the
> default preemption mode??
>
> How does this setting affect the real-time performance of a xenomai
> enabled kernel?
This option is about Linux preemption, it affects how often Linux is
willing to preempt itself, in the throughput/latency fight, it gives
advantage to (Linux) latency at the expense of througput. It does not
affect Xenomai directly, but rather indirectly: it creates a code with a
lower "density", by littering the Linux kernel execution with checks for
the need of rescheduling, so that Linux has a larger pollution effect on
caches. In my experience, you get slightly lower Linux latencies by
turning CONFIG_PREEMPT off (selecting CONFIG_PREEMPT_NONE).
--
Gilles.
next prev parent reply other threads:[~2014-08-28 20:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-28 19:49 [Xenomai] Low-latency desktop setting Yogi A. Patel
2014-08-28 20:02 ` Gilles Chanteperdrix [this message]
2014-08-28 20:15 ` Gilles Chanteperdrix
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=53FF8AC7.5090301@xenomai.org \
--to=gilles.chanteperdrix@xenomai.org \
--cc=xenomai@xenomai.org \
--cc=yapatel@gatech.edu \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.