On 07/20/2015 01:59 PM, Dario Faggioli wrote:
On Mon, 2015-07-20 at 13:41 +0200, Juergen Gross wrote:
On 07/17/2015 03:35 PM, Dario Faggioli wrote:
@@ -644,25 +673,66 @@ int cpu_disable_scheduler(unsigned int cpu)
cpumask_setall(v->cpu_hard_affinity);
}
- if ( v->processor == cpu )
+ if ( v->processor != cpu )
{
- set_bit(_VPF_migrating, &v->pause_flags);
+ /* This vcpu is not on cpu, so we can move on. */
vcpu_schedule_unlock_irqrestore(lock, flags, v);
- vcpu_sleep_nosync(v);
- vcpu_migrate(v);
+ continue;
+ }
+
+ /* If it is on cpu, we must send it away. */
+ if ( unlikely(system_state == SYS_STATE_suspend) )
+ {
+ /*
+ * If we are doing a shutdown/suspend, it is not necessary to
+ * ask the scheduler to chime in. In fact:
+ * * there is no reason for it: the end result we are after
+ * is just 'all the vcpus on the boot pcpu, and no vcpu
+ * anywhere else', so let's just go for it;
+ * * it's wrong, for cpupools with only non-boot pcpus, as
+ * the scheduler would always fail to send the vcpus away
+ * from the last online (non boot) pcpu!
+ *
+ * Therefore, in the shutdown/suspend case, we just pick up
+ * one (still) online pcpu. Note that, at this stage, all
+ * domains (including dom0) have been paused already, so we
+ * do not expect any vcpu activity at all.
+ */
+ cpumask_andnot(&online_affinity, &cpu_online_map,
+ cpumask_of(cpu));
+ BUG_ON(cpumask_empty(&online_affinity));
+ /*
+ * As boot cpu is, usually, pcpu #0, using cpumask_first()
+ * will make us converge quicker.
+ */
+ new_cpu = cpumask_first(&online_affinity);
+ vcpu_move_nosched(v, new_cpu);
Shouldn't there be a vcpu_schedule_unlock_irqrestore() ?
I'm sure I put one there, as I was sure that it was there the last time
I inspected the patch before hitting send.
But I see that it's not there now, so I must have messed up when
formatting the patch, or something like that. :-(
It's really really weird, as I forgot it during development, and then
the system was hanging, and then I added it, and that's why I'm sure I
did have it in place... but perhaps I fat fingered some stgit command
which made it disappear.
Or you forgot stg refresh? I just managed to do so. :-(
Juergen
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