SMP irq question

Victor Yodaiken (
Sun, 18 May 1997 16:33:12 -0600

SMP questions.
In the following code you ack _after_ clearing the tlb.
A) Why? On all other interrupts we ack first.
B) How time critical is this event? On the one hand, I don't
want to hang Linux on the other processors while theRT system
runs, but on the other hand I don't want to pay the performance
cost during a rt process .
C) Am I correct in assuming that the critical material to flush,
fter bootup, will be in user space.

asmlinkage void smp_invalidate_interrupt(void)
if (test_and_clear_bit(smp_processor_id(), &smp_invalidate_needed))

ack_APIC_irq ();