It polls the serial port continually :-( Dave
-----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Steve Rooke Sent: 03 January 2010 12:00 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Lady Heather Overhead Well, it then looks like it is going through this rapid loop of giving up processing power and asking for it again immediately, and on my system there is plenty of spare capacity so it gets its thread back again. Perhaps this is what is generating all the masses of system calls as the balance between user and system processing is all wrong. Does the code not indicate that it needs CPU via waits, real sleeps or interrupts on I/O and the like. Just believing that the system it is running on is solely dedicated to it seems a little strange to me but then I come from a multitasking background where we learn to share, and have CPU idle time. Steve Rooke 2010/1/1 Mark Sims <hol...@hotmail.com>: > > An idle Windows machine allocates 50% of its resources to a task when it starts up. This shows up as 50% CPU utilization. A second Heather will show as around 100% total utilization (50 % each). These usage numbers are totally bogus. > > Heather VERY periodically returns it's time slot to the system with the flag that says, "Hey, if you aren't doing anything else, I'd kinda like that time back.". So if you bring up four Heathers, each will then show 25% utilization, etc. I have seen a dozen Heathers running on a fairly slow machine (and quite a sight it is). > > Basically all the Heathers soak up all the free time on the system and share it amongst themselves. The program runs just fine on a 100 MHz WIN98 laptop. If you are actually using a full core, you have other problems... > > There is a recently added command line flag (/tw=msecs) that says to force Sleep(msecs) calls in place of Sleep(0) calls. It slows the system response time down, but might be useful for power saving on laptops, etc. > > > > > > > > > > > Mark John > > from a nut post: >> do know that >> > there is a fair amount of processor load, including a lot of system >> > calls. On my system, running LH under wine takes the equivalent of 1 >> CPU > on my quad core. > > > I'm sure not new to you and I hardly know what I'm talking about BUT > what I have noticed is: > > MY LadyHeather programs > will take all the spare windows processor time available even on my > fastest windows XT machine. > And then again I have no trouble running at least four simultaneous LH > programs (even different versions) all at the same time on a slow > machine, so they don't need much, they'll just take whatever is > available, but they seem to share well. > > > > _________________________________________________________________ > Hotmail: Trusted email with powerful SPAM protection. > http://clk.atdmt.com/GBL/go/177141665/direct/01/ > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Steve Rooke - ZL3TUV & G8KVD A man with one clock knows what time it is; A man with two clocks is never quite sure. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.