Re: [Lse-tech] Re: CPU affinity & IPI latency (FIX)_

[Davide Libenzi]

On 17-Jul-2001 Hubertus Frnake wrote:
> In an attempt to inline the code, somehow the tabs got lost. So here is the
> attached correct patch fo 2.4.5. Please try and let me know whether you
> see your problems disappear and/or others arise.
> The sketchy writeup is still the same.

What is the reason You don't set the resched task in the fast path ?

        best_cpu = p->processor;
        if (can_schedule(p, best_cpu)) {
                tsk = idle_task(best_cpu);
                if ((cpu_curr(best_cpu) == tsk) &&
                    (cpu_resched(best_cpu) == NULL)) {
                        int need_resched;
send_now_idle:
                        /*
                         * If need_resched == -1 then we can skip sending
                         * the IPI altogether, tsk->need_resched is
                         * actively watched by the idle thread.
                         */
                        need_resched = tsk->need_resched;
                        tsk->need_resched = 1;
                        if ((best_cpu != this_cpu) && !need_resched) {
>>>>                            cpu_resched(best_cpu) = p;
                                smp_send_reschedule(best_cpu);
                        }
                        return;
                }
        }

- Davide