From: Chris Friesen <chris.friesen@windriver.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Corey Minyard <cminyard@mvista.com>
Cc: <rolf.freitag@email.de>, <linux-rt-users@vger.kernel.org>
Subject: Re: Why is real time pinging not possible with RT kernels?
Date: Tue, 13 Jun 2017 10:06:45 -0600 [thread overview]
Message-ID: <59400D95.8000304@windriver.com> (raw)
In-Reply-To: <20170613115818.yjjoec3kojryuxam@linutronix.de>
On 06/13/2017 05:58 AM, Sebastian Andrzej Siewior wrote:
> On 2017-06-12 07:57:18 [-0500], Corey Minyard wrote:
>> A few notes on what you have done:
>>
>> * ionice doesn't affect network I/O.
>> * renice does not set real-time priorities.
>> * You don't do anything with memory locking. What happens
>> if memory in your program gets paged out then is required?
>> * Something on the other end of the ping is running, too. It
>> also needs to be real-time, too, and it's not by default.
>
> You forgot to mention that the real-time kernel is not automatically
> overclocking the software in terms of performance (but providing
> determinism).
Pinging localhost *should* be reasonably quick. It's basically a test of the
scheduler and context switching (once all the memory is locked in place).
Chris
next prev parent reply other threads:[~2017-06-13 16:07 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-10 18:13 Why is real time pinging not possible with RT kernels? rolf.freitag
2017-06-12 5:10 ` Chris Friesen
2017-06-12 12:57 ` Corey Minyard
2017-06-12 13:17 ` Peter C. Wallace
2017-06-12 16:45 ` Chris Friesen
2017-06-12 17:16 ` Corey Minyard
2017-06-17 8:37 ` rolf.freitag
2017-06-17 12:10 ` Corey Minyard
2017-06-13 11:58 ` Sebastian Andrzej Siewior
2017-06-13 16:06 ` Chris Friesen [this message]
2017-06-13 16:53 ` Corey Minyard
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=59400D95.8000304@windriver.com \
--to=chris.friesen@windriver.com \
--cc=bigeasy@linutronix.de \
--cc=cminyard@mvista.com \
--cc=linux-rt-users@vger.kernel.org \
--cc=rolf.freitag@email.de \
/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.