Re: 2.6.14-rt1

[Carlos Antunes <cmantunes@gmail.com>]

On 11/1/05, Fernando Lopez-Lezcano <nando@ccrma.stanford.edu> wrote:
> On Tue, 2005-11-01 at 12:18 -0800, Fernando Lopez-Lezcano wrote:
> > On Sun, 2005-10-30 at 14:33 +0100, Ingo Molnar wrote:
> > > i have released the 2.6.14-rt1 tree, which can be downloaded from the
> > > usual place:
> > >
> > >    http://redhat.com/~mingo/realtime-preempt/
> > >
> > > this release is mainly about ktimer fixes: it updates to the latest
> > > ktimer tree from Thomas Gleixner (which includes John Stultz's latest
> > > GTOD tree), it fixes TSC synchronization problems on HT systems, and
> > > updates the ktimers debugging code.
> > >
> > > These together could fix most of the timer warnings and annoyances
> > > reported for 2.6.14-rc5-rt kernels. In particular the new
> > > TSC-synchronization code could fix SMP systems: the upstream TSC
> > > synchronization method is fine for 1 usec resolution, but it was not
> > > good enough for 1 nsec resolution and likely caused the SMP bugs
> > > reported by Fernando Lopez-Lezcano and Rui Nuno Capela.
> > >
> > > Please re-report any bugs that remain.
> >
> > 2.6.14-rt2 seems to be running fine on my athlon x2 smp system. Apart
> > from some time warp messages when starting up it looks fine so far (this
> > is on fc4).
>
> Actually, after enough time logged in (or maybe just with the kernel
> running without a reboot) I still get the usual Jack warnings:
>
> delay of 5469.000 usecs exceeds estimated spare time of 2641.000;
> restart ...
>

Fernando,

I'm also having some when using SCHED_FIFO and SCHED_RR. When running
several hundred threads, each sleeping on a loop for 20ms, SCHED_OTHER
performs ok with latencies of less than 10ms while with SCHED_FIFO or
SCHED_RR, I see latencies exceeding 1 full second!

Carlos


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