Re: Timing in seq record

[Andrew Johnson via Tech-talk <tech-talk at aps.anl.gov>]

    On 3/3/22 9:56 AM, Michael Davidsaver wrote:
> On
>       3/3/22 05:21, Mark Rivers via Tech-talk wrote:
>       
> > I believe Freddie is correct in his more
> >         recent message:
> >         
> >         
> > > There were timers waking up early, but
> > >           also half a quantum being subtracted from the time value asked
> > >           for, I think to give a good average wakeup time for systems
> > >           when wakeup is on boundaries of the quantum. I see that this
> > >           subtraction still happens
> > >           
> > >         
> >         
> >         This looks like a problem of quantum/2 subtraction.
> >         
> >       
>       
>       I agree that this arbitrary shortening is a ~bug, but it is worth
>       remembering
>       
>       that my attempt at removing this it caused a problem for you
>       (Mark) on vxworks.
>       
>       
>       https://bugs.launchpad.net/epics-base/+bug/1861612/comments/12
>       
>       
>       There are some known problems with using epicsTimer for precise,
>       short, delays.
>       
>     
    
    One thing Mark could try would be to set the sleep quantum to 0 on
    Linux. I've not looked at the code for ages so I don't know if it
    will cause other problems (please do a 'make runtests' after
    changing it to look for possible issues).
    
    - Andrew
    
-- 
Complexity comes for free, Simplicity you have to work for.