On Tue, May 24, 2005 at 11:01:50PM +0200, Matthias Schwarzott wrote:
> On Tuesday 24 May 2005 19:15, Dr. Werner Fink wrote:
> > On Tue, May 24, 2005 at 04:31:31PM +0100, Darren Salt wrote:
> > > I demand that Matthias Schwarzott may or may not have written...
> > >
> > > > in the last days I come accross a strange phenomen: One vdr thread eats
> > > > up to 45% cpu on my Pentium3 700Mhz system when I did nothing with my
> > > > vdr except live viewing on a ff card without transfer mode. Some
> > > > digging resulted in this:
> > > > - The thread is the section handler thread.
> > > > - The cpu-load depends on the transponder currently watching on.
> > >
> > > [snip]
> > >
> > > > Attached is a Patch to simply add one sleep(1) inte the loop before the
> > > > poll. This results in reducing the cpu-load from 45% to 1.3%. And it
> > > > does not seem to lose any sections.
> > >
> > > If you replace that sleep(1) with sched_yield(), do you see the same
> > > effect wrt CPU load?
> >
> > Wouldn't be pthread_yield() the better solution?
> >
>
> I tested sched_yield and pthread_yield and both did not change anything. The
> cpu load is the same as with an unchanged vdr.
Then two question rises: How often is this point of code reached
and how often is the code after this point used all over the time?
Maybe a solution with a condition variable to use a broadcast
if a few sections are received for waking up the point would help.
Werner
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