From: Clemens Ladisch <clemens@ladisch.de>
To: Thomas Gleixner <tglx@linutronix.de>,
Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: linux-kernel@vger.kernel.org,
linux1394-devel@lists.sourceforge.net,
Peter Zijlstra <peterz@infradead.org>,
John Stultz <john.stultz@linaro.org>
Subject: Re: firewire: CLOCK_MONOTONIC_RAW exposure
Date: Wed, 16 Jul 2014 13:34:21 +0200 [thread overview]
Message-ID: <53C6633D.9080905@ladisch.de> (raw)
In-Reply-To: <alpine.DEB.2.10.1407161151450.24854@nanos>
Thomas Gleixner wrote:
> I wonder why firewire exposed CLOCK_MONOTONIC_RAW to user space.
>
> What's the purpose of that? CLOCK_MONOTONIC_RAW is the raw time based
> on the initial frequency setup of the clocksource. That can be quite
> off from the NTP corrected frequency which is exposed by
> CLOCK_MONOTONIC.
The purpose is to get a stable clock, i.e., to avoid clock rate changes
caused by NTP corrections.
ALSA is adding CLOCK_MONOTONIC_RAW for the same reason.
Regards,
Clemens
next prev parent reply other threads:[~2014-07-16 12:30 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-16 9:57 firewire: CLOCK_MONOTONIC_RAW exposure Thomas Gleixner
2014-07-16 11:34 ` Clemens Ladisch [this message]
2014-07-16 12:37 ` Peter Zijlstra
2014-07-16 14:16 ` Clemens Ladisch
2014-07-16 15:00 ` Mark Brown
2014-07-17 8:37 ` Daniel Thompson
2014-07-17 13:19 ` Thomas Gleixner
2014-07-17 16:14 ` John Stultz
2014-07-17 16:34 ` Daniel Thompson
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=53C6633D.9080905@ladisch.de \
--to=clemens@ladisch.de \
--cc=john.stultz@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux1394-devel@lists.sourceforge.net \
--cc=peterz@infradead.org \
--cc=stefanr@s5r6.in-berlin.de \
--cc=tglx@linutronix.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox