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

Erich Focht
2002-01-21T18:24:08Z

Please ignore my previous email. The interrupt can of course come from
within the context_switch() part in schedule(), where psr.i is set.

Unfortunately the context switch in Ingo's scheduler happens with the
runqueue lock held, which can lead to a deadlock eg. if the timer
interrupt is called inside and sched_tick spinlocks on the runqueue lock
held by schedule(). On IA64 (HZ\x1024) this probably happens much more
frequently than on IA32 (HZ\x100).

Regards,
Erich

On Sat, 19 Jan 2002, David Mosberger wrote:

> 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