Re: [Xenomai-core] [PATCH] Fix __ipipe_pin_range_globally

[Philippe Gerum <rpm@xenomai.org>]

On Sun, 2007-10-07 at 18:51 +0200, Philippe Gerum wrote:
> On Sun, 2007-10-07 at 18:40 +0200, Jan Kiszka wrote:
> > > 
> > > I still have a problem with UP here, but this one is due to a
> Xenomai
> > > bug -- host timer is no more forwarded when the nucleus timer
> starts.
> > > Does disabling NOHZ & HIRES get things working on your setup?
> > > 
> > 
> > Yes, I have HIRES on, and I guess that's the point: My current
> > impression is that there are some bits in Xenomai missing to migrate
> > running hires timers from Linux's lapic clockevent device over
> xntimers. 
> > The effect here is that CPU0 continues (probably due to higher timer
> > load) while CPU1 stops scheduling timers:
> > 
> > CPU  SCHEDULED   FIRED       TIMEOUT    INTERVAL   HANDLER      NAME
> > 0    2729        2727        31168      -          NULL
> [host-timer/0]
> > 0    11          10          305103844  1000000000  xnpod_watch
> [watchdog]
> > 1    11          10          309365472  1000000000  xnpod_watch
> [watchdog]
> > 
> 
> The issue I see would be different it seems. I can reproduce the
> problem
> in UP + PIT mode, LAPIC off.

Ok, there is very likely a basic flaw in the logic for sharing the
oneshot mode between the clock event manager and Xenomai, when it comes
to relaying the host tick from the latter; something like a silly catch
22 issue. I'll send more on this later, but this probably impacts all
setups, LAPIC enabled or not. More on this later, I need to sort out a
few things more.
 
-- 
Philippe.