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
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