On 06/17/2011 01:03 PM, Jan Kiszka wrote: > On 2011-06-17 12:55, Gilles Chanteperdrix wrote: >> On 06/17/2011 11:26 AM, Jan Kiszka wrote: >>> Our current interrupt handlers assume that they leave over the same task >>> and CPU they entered. But CONFIG_XENO_HW_UNLOCKED_SWITCH and commit >>> f6af9b831c broke this assumption: xnpod_schedule invoked from the >>> handler tail can now actually trigger a domain migration >> >> What unlocked context swith introduce from my point of view is simply >> sections where interrupt happen which do not reschedule. >> >> f6af9b831c introduce a rescheduling point, but does not change what >> happens during the interrupt handler either. >> >> So, I do not really understand this commit message. Either we can assume >> that interrupt handlers migrate tasks or not, but this does not seem to >> have anything to do with unlocked context switches or commit f6af9b831c. > > It has: Task is about to relax, re-enables interrupts in > xnpod_resume_thread, IRQ hits, handler is entered over the relaxing RT > task, xnpod_schedule in its tail performs the switch to root, which then > continues to relaxed task, IRQ tail resumes over a different task, on > SMP potentially also on a different CPU. I can send you a the trace if > you want to have a closer look.
Ok. Got it. But what has this to do with unlocked context switches ? -- Gilles. _______________________________________________ Xenomai-core mailing list Xenomaiemail@example.com https://mail.gna.org/listinfo/xenomai-core