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From: John Stultz <john.stultz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
To: Dmitry Antipov <dmitry.antipov-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: Andrew Richardson
	<chardson-63aXycvo3TyHXe+LvDLADg@public.gmane.org>,
	linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linaro-dev-cunTk1MwBs8s++Sfvej+rw@public.gmane.org
Subject: Re: Minimum timing resolution in Ubuntu/Linaro on the PandaBoard ES
Date: Wed, 08 Feb 2012 08:58:42 -0800	[thread overview]
Message-ID: <1328720322.8119.7.camel@js-netbook> (raw)
In-Reply-To: <4F32063F.1020607-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>

On Tue, 2012-02-07 at 21:21 -0800, Dmitry Antipov wrote:
> BTW, I have no ideas why clock_getres(CLOCK_REALTIME,...) returns {0, 1}
> regardless of underlying clock source. I expect {0, 30517} for 32K timer
> and {0, 26} for MPU timer.

Yea. I had proposed to export the underlying clocksource's resolution
via clock_getres, but it was argued against. The concern is that
applications might not expect clock_getres to change while the
application is running.  Between any clock_getres() call and a time
read, the clocksources could change.

But if someone has a different reading of the posix spec, it might be
good to revisit this.

thanks
-john

  parent reply	other threads:[~2012-02-08 16:58 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <4F31A91B.8080106@umich.edu>
2012-02-08  5:21 ` Minimum timing resolution in Ubuntu/Linaro on the PandaBoard ES Dmitry Antipov
     [not found]   ` <4F32063F.1020607-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2012-02-08  9:32     ` Andrew Richardson
2012-02-08 13:55       ` Dmitry Antipov
2012-02-08 14:21         ` Andrew Richardson
2012-02-08 17:05       ` John Stultz
2012-02-08 17:08       ` John Stultz
2012-02-08 18:19         ` Turgis, Frederic
2012-02-08 16:58     ` John Stultz [this message]
2012-02-10  0:56   ` Ming Lei

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