| Message ID | 148467403070.27920.13927682504995274110.stgit@Solace.fritz.box (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jan 17, 2017 at 5:27 PM, Dario Faggioli <dario.faggioli@citrix.com> wrote: > In fact, when domains are being unpaused: > - it's not necessary to put the vcpu to sleep, as > they are all already paused; > - it is not necessary to call vcpu_migrate(), as > the vcpus are still paused, and therefore won't > wakeup anyway. > > Basically, the only important thing is to call > pick_cpu, to let the scheduler run and figure out > what would be the best initial placement (i.e., the > value stored in v->processor), for the vcpus, as > they come back up, one after another. > > Note that this is consistent with what was happening > before this change, as vcpu_migrate() calls pick_cpu. > But much simpler and quicker. > > Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com> Reviewed-by: George Dunlap <george.dunlap@citrix.com> > --- > Cc: George Dunlap <george.dunlap@eu.citrix.com> > --- > xen/common/schedule.c | 22 ++++++++++------------ > 1 file changed, 10 insertions(+), 12 deletions(-) > > diff --git a/xen/common/schedule.c b/xen/common/schedule.c > index bee5d1f..43b5b99 100644 > --- a/xen/common/schedule.c > +++ b/xen/common/schedule.c > @@ -635,7 +635,11 @@ void restore_vcpu_affinity(struct domain *d) > > for_each_vcpu ( d, v ) > { > - spinlock_t *lock = vcpu_schedule_lock_irq(v); > + spinlock_t *lock; > + > + ASSERT(!vcpu_runnable(v)); > + > + lock = vcpu_schedule_lock_irq(v); > > if ( v->affinity_broken ) > { > @@ -659,17 +663,11 @@ void restore_vcpu_affinity(struct domain *d) > cpupool_domain_cpumask(v->domain)); > v->processor = cpumask_any(cpumask_scratch_cpu(cpu)); > > - if ( v->processor == cpu ) > - { > - set_bit(_VPF_migrating, &v->pause_flags); > - spin_unlock_irq(lock);; > - vcpu_sleep_nosync(v); > - vcpu_migrate(v); > - } > - else > - { > - spin_unlock_irq(lock); > - } > + spin_unlock_irq(lock);; > + > + lock = vcpu_schedule_lock_irq(v); > + v->processor = SCHED_OP(VCPU2OP(v), pick_cpu, v); > + spin_unlock_irq(lock); > } > > domain_update_node_affinity(d); > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > https://lists.xen.org/xen-devel
diff --git a/xen/common/schedule.c b/xen/common/schedule.c index bee5d1f..43b5b99 100644 --- a/xen/common/schedule.c +++ b/xen/common/schedule.c @@ -635,7 +635,11 @@ void restore_vcpu_affinity(struct domain *d) for_each_vcpu ( d, v ) { - spinlock_t *lock = vcpu_schedule_lock_irq(v); + spinlock_t *lock; + + ASSERT(!vcpu_runnable(v)); + + lock = vcpu_schedule_lock_irq(v); if ( v->affinity_broken ) { @@ -659,17 +663,11 @@ void restore_vcpu_affinity(struct domain *d) cpupool_domain_cpumask(v->domain)); v->processor = cpumask_any(cpumask_scratch_cpu(cpu)); - if ( v->processor == cpu ) - { - set_bit(_VPF_migrating, &v->pause_flags); - spin_unlock_irq(lock);; - vcpu_sleep_nosync(v); - vcpu_migrate(v); - } - else - { - spin_unlock_irq(lock); - } + spin_unlock_irq(lock);; + + lock = vcpu_schedule_lock_irq(v); + v->processor = SCHED_OP(VCPU2OP(v), pick_cpu, v); + spin_unlock_irq(lock); } domain_update_node_affinity(d);
In fact, when domains are being unpaused: - it's not necessary to put the vcpu to sleep, as they are all already paused; - it is not necessary to call vcpu_migrate(), as the vcpus are still paused, and therefore won't wakeup anyway. Basically, the only important thing is to call pick_cpu, to let the scheduler run and figure out what would be the best initial placement (i.e., the value stored in v->processor), for the vcpus, as they come back up, one after another. Note that this is consistent with what was happening before this change, as vcpu_migrate() calls pick_cpu. But much simpler and quicker. Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com> --- Cc: George Dunlap <george.dunlap@eu.citrix.com> --- xen/common/schedule.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-)