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 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.