spinlock <-> IRQ Problem

ruhl22 · 10-05-2004, 08:24 AM

Hi.. i hava an exam tomorrow...linux kernel and I can't figure out a logical problem. IRQ are handled on the Kernel Stack. It's about SMP.
Why can not be uded spinlocks in IRQ Routines? It involves the Stack Pointer...something about loosing its referene, but i coudn't figure it out...

A detailed answere about the problem and how it can be handeled (by saving the Stack pointer reference)would be my salvation

Thanks a lot and i hope the answere will come today, so that i can "rule" tomorrow.

infamous41md · 10-05-2004, 09:35 AM

Uhh, spinlocks _are_ used in IRQ handlers, it's the only way to provide locking between an IRQ handler(s), and other kernel code.