Hello,
Damien Zammit via Bug reports for the GNU Hurd, le sam. 21 déc. 2024 23:55:25
+0000, a ecrit:
> @@ -341,12 +312,16 @@ start_other_cpus(void)
> lapic_disable();
>
> bspdone = 0;
> +
> + /* This is set once for all APs to use */
> + pmap_make_temporary_mapping();
> +
> + smp_startup_cpus(apic_get_cpu_apic_id(0), apboot_addr);
> +
> for (cpu = 1; cpu < ncpus; cpu++) {
> machine_slot[cpu].running = FALSE;
>
> - //Start cpu
> - printf("Starting AP %d\n", cpu);
> - cpu_start(cpu);
This is introducing a race: we'd want a synchronization barrier between
setting running to FALSE and unleashing the cpu setup with bspdone++.
That being said, do we really need synchronizing on bspdone at all? the
BSP can as well just set all running to FALSE before calling
smp_startup_cpus, and then just wait for running to become TRUE on all
processors.
> + printf("Waiting for AP %d\n", cpu);
>
> bspdone++;
> do {
> @@ -357,6 +332,14 @@ start_other_cpus(void)
> }
> printf("BSP: Completed SMP init\n");
>
> + pmap_remove_temporary_mapping();
> +
> + /* Flush TLB on all cpu groups */
> + ncpus = (ncpus < 8) ? ncpus : 8;
This magic 8 definitely deserves a macro.
> + for (cpu = 1; cpu < ncpus; cpu++) {
> + interrupt_processor(cpu);
> + }
> +
> /* Re-enable IOAPIC interrupts as per setup */
> lapic_enable();
> }
Samuel
