Re: [gpsd-dev] gpsd processor load

[Gary E. Miller]

Yo Greg!

On Wed, 30 Oct 2013 18:44:41 -0400
Greg Troxel <address@hidden> wrote:

> Nope, it's not select.  I ran ktrace, and the thread that reads from
> the device is fine.  The pps/shm thred is in a tight loop doing
> gettimeofday.  The problem is that the loop in gpsd_ppsmonitor has
> very little body content if both TIOCMIWAIT and SYS_TIMEPPS are both
> undefined.  NetBSD has sys/timepps.h, but it needs sys/types.h, so
> it's undefined.  As I read the code, it will be in an infinite tight
> loop calling gettimeofday and then logging a debug message if neither
> method is available.

Yeah.  the ifdef's got changed.  No point trying PPS at all if no 
TIOCMIWAIT.  That was a recetnly added bug.

> The new code disables pps if TIOCMIWAIT is not present.

Which reverts to the right thing to do.

> I'm not sure
> that's right, as kpps might be able to work, but I will figure it out
> before asking for that to change.

TIOCMIWAIT is what sleeps and wakes up the thread.  It would need to be
replaced with some sort of usleep() and then KPPS would need to actually
work on BSD.  Doable, but a lot of work, and only a BSD person could do
it.  

RGDS
GARY
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Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97701
        address@hidden  Tel:+1(541)382-8588

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