On Thu, 10 Jan 2002, Rusty Russell wrote:
> Another question:
>
> if (likely(prev != next)) {
> rq->nr_switches++;
> rq->curr = next;
> next->cpu = prev->cpu;
> context_switch(prev, next);
> /*
> * The runqueue pointer might be from another CPU
> * if the new task was last running on a different
> * CPU - thus re-load it.
> */
> barrier();
> rq = this_rq();
> }
> spin_unlock_irq(&rq->lock);
>
> I do not understand this comment. How can rq (ie. smp_processor_id())
> change? Nothing sleeps here, and if it DID change, the
> spin_unlock_irq() would be wrong...
If you switch you'll on the stack the rq of the previous cpu
spin_unlock_irq(&rq->lock) is fine if you do not switch and if you switch
you need to reload rq
- Davide
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This archive was generated by hypermail 2b29 : Tue Jan 15 2002 - 21:00:30 EST