Jeff Weber wrote:
> On Wed, Mar 23, 2011 at 2:37 AM, Gilles Chanteperdrix <
> [email protected]> wrote:
>
>> Jeff Weber wrote:
>>> I need to timetag events from a realtime context with a NPT-synchronized
>>> system clock. This topic comes up periodically on the mailing list.
>> Last I
>>> recall, there was talk of adding the capability via an alternate
>>> (non-CLOCK_REALTIME) clock_id. What is the status of this topic?
>> The CLOCK_HOST_REALTIME is available in the xenomai-head branch (to be
>> 2.6 branch, soon). It requires modifications of the I-pipe patch which
>> are available, at least, on x86, but are probably not really hard to
>> implement on other platforms.
>>
>
> clock_gettime(CLOCK_HOST_REALTIME) fails when called from kernel, and from
> clocktest. Any ideas why?
> Does the CLOCK_HOST_REALTIME need to be initialized in some way?
> Test and config follow.
>
> TIA,
> Jeff
>
>
>
> # /usr/xenomai/bin/clocktest -D -C 42
> hostrt data area is not live
> clock_gettime failed for clock id 42
> hostrt data area is not live
>
> # grep -rw CLOCK_HOST_REALTIME /usr/xenomai/include/
> /usr/xenomai/include/posix/time.h:#define CLOCK_HOST_REALTIME 42
>
> # zgrep HOSTRT /proc/config.gz
> CONFIG_XENO_OPT_HOSTRT=y
> CONFIG_HAVE_IPIPE_HOSTRT=y
>
> # cat /proc/xenomai/version
> 2.5.90
>
> # cat /proc/ipipe/version
> 2.9-00
>
> # uname -r
> 2.6.37.3-xeno-head-smp
>
> Architecture is x86 32-bit SMP with TSC.
CLOCK_HOST_REALTIME will work, only if the Linux kernel also uses the
TSC as its clocksource. So, check the "Switching to clocksource"
messages, or "disabling.*tsc" in the kernel log to see if the kernel has
not decided to use another clock source.
--
Gilles.
_______________________________________________
Xenomai-help mailing list
[email protected]
https://mail.gna.org/listinfo/xenomai-help
