Re: [Linux-ia64] Help with Ingo scheduler on IA64

David Mosberger
2002-01-19T20:10:01Z

>>>>> On Sat, 19 Jan 2002 18:17:43 +0100 (MET), Erich Focht <focht@ess.nec.de> said:

Erich> interrupts are disabled. Looking into the IA64 manuals
Erich> I find that the text about psr.i emntions only disabling
Erich> external interrupts, not the timer interrupt or internal
Erich> interrupts coming from the local APIC (i.e. IPIs could also
Erich> appear?).

Erich> Does anybody know whether psr.i disables all interrupts or
Erich> not? I tried setting the mmi bit on cr.tpr (mask maskable
Erich> interrupts) in local_irq_disable() and local_irq_restore(),
Erich> but I still see this kind of lockups.

Erich> A quick fix for the scheduler is to return from the timer
Erich> interrupt when the local runqueue is locked (same probably
Erich> for IPIs) but ... isn't there a method to disable ALL
Erich> interrupts?

psr.i *does* disable all interrupts, including NMI. Device interrupts
are generally referred to as "external interrupts" in the ia64
manuals. If you read the manual, you'll find there is no ambiguity
about this at all. For example, see Table 5-8: External Interrupt
Control Registers; it lists ITV...

--david