Messages in this thread | | | Date | Fri, 20 Jan 2006 07:26:50 -0600 | From | Jack Steiner <> | Subject | Re: [PATCH] SN2 user-MMIO CPU migration |
| |
On Thu, Jan 19, 2006 at 06:18:43PM -0800, Jesse Barnes wrote: > On Thursday, January 19, 2006 4:06 pm, Brent Casavant wrote: > > #ifndef __ARCH_WANT_UNLOCKED_CTXSW > > static inline int task_running(runqueue_t *rq, task_t *p) > > @@ -936,6 +939,7 @@ static int migrate_task(task_t *p, int d > > * it is sufficient to simply update the task's cpu field. > > */ > > if (!p->array && !task_running(rq, p)) { > > + arch_task_migrate(p); > > set_task_cpu(p, dest_cpu); > > return 0; > > } > > @@ -1353,6 +1357,7 @@ static int try_to_wake_up(task_t *p, uns > > out_set_cpu: > > new_cpu = wake_idle(new_cpu, p); > > if (new_cpu != cpu) { > > + arch_task_migrate(p); > > set_task_cpu(p, new_cpu); > > task_rq_unlock(rq, &flags); > > /* might preempt at this point */ > > @@ -1876,6 +1881,7 @@ void pull_task(runqueue_t *src_rq, prio_ > > { > > dequeue_task(p, src_array); > > dec_nr_running(p, src_rq); > > + arch_task_migrate(p); > > set_task_cpu(p, this_cpu); > > inc_nr_running(p, this_rq); > > enqueue_task(p, this_array); > > @@ -4547,6 +4553,7 @@ static void __migrate_task(struct task_s > > if (!cpu_isset(dest_cpu, p->cpus_allowed)) > > goto out; > > > > + arch_task_migrate(p); > > set_task_cpu(p, dest_cpu); > > if (p->array) { > > /* > > Maybe you could just turn the above into mmiowb() calls instead? That > would cover altix, origin, and ppc as well I think. On other platforms > it would be a complete no-op. > > Jesse
I don't think calling mmiob() directly would work. In order to make CONFIG_IA64_GENERIC work, the call to mmiob() needs to be underneath a platform vector. Using ia64_platform_is() would also work but I think a platform vector is cleaner.
A second reason for an arch_task_migrate() instead of a specific mmiob() is to provide a hook for a future platform that require additional work to be done when a task migrates.
-- Thanks
Jack Steiner (steiner@sgi.com) 651-683-5302
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |