Re: [PATCH] to fix xtime lock for in the RT kernel patch

[George Anzinger]

George Anzinger wrote:
> Ingo Molnar wrote:
>
> > * George Anzinger <george@xxxxxxxxxx> wrote:
> >
> >
> > > What I am suggesting is spliting the mark code so that it would only
> > > grap the offset (current TSC in most systems) during interrupt
> > > processing.  Applying this would be done later in the thread.  Since
> > > it is not applying the offset, the xtime_lock would not need to be
> > > taken.
> >
> >
> >
> > ok, you are right, and this would be fine with me. Wanna take a shot at
> > it? I've uploaded the -03 patch which is my most current tree. (with the
> > do_timer() moving done already.) I've reviewed the TSC offset codepath
> > again and i'm not sure where i got the 10 usecs from ... it's a pretty
> > cheap codepath that can be done in the direct interrupt just fine.
> Tomorrow, uh, later today.  Need some sleep now...

Ingo, I have been looking at the code being proposed by John Stultz.  It looks 
like it handles all the issues I am talking about here.  I think it would be 
best to leave the RT patch as it is WRT this issue and work on getting John's 
patch ready for prime time as any work I would do here will just get tossed when 
his patch hits the steet.

Meanwhile, I will (already have) get HRT working on RT and make that available 
in the next few days.

--
George Anzinger   george@xxxxxxxxxx
High-res-timers:  http://sourceforge.net/projects/high-res-timers/

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