With a scheduling granularity greater than 1 multiple vcpus share the
same struct sched_unit. Support that.
Setting the initial processor must be done carefully: we can't use
sched_set_res() as that relies on for_each_sched_unit_vcpu() which in
turn needs the vcpu already as a member of the domain's vcpu linked
list, which isn't the case.
Signed-off-by: Juergen Gross
---
V4:
- merge patch 36 of V3 into this one (Jan Beulich)
- add some comments (Jan Beulich)
- use unit_id instead of vcpu_list->vcpu_id (Jan Beulich)
---
xen/common/schedule.c | 97 ---
1 file changed, 76 insertions(+), 21 deletions(-)
diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index ae5c807c6a..b11a1c2538 100644
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -347,7 +347,7 @@ static void sched_spin_unlock_double(spinlock_t *lock1,
spinlock_t *lock2,
spin_unlock_irqrestore(lock1, flags);
}
-static void sched_free_unit(struct sched_unit *unit)
+static void sched_free_unit_mem(struct sched_unit *unit)
{
struct sched_unit *prev_unit;
struct domain *d = unit->domain;
@@ -366,8 +366,6 @@ static void sched_free_unit(struct sched_unit *unit)
}
}
-unit->vcpu_list->sched_unit = NULL;
-
free_cpumask_var(unit->cpu_hard_affinity);
free_cpumask_var(unit->cpu_hard_affinity_saved);
free_cpumask_var(unit->cpu_soft_affinity);
@@ -375,18 +373,65 @@ static void sched_free_unit(struct sched_unit *unit)
xfree(unit);
}
+static void sched_free_unit(struct sched_unit *unit, struct vcpu *v)
+{
+struct vcpu *vunit;
+unsigned int cnt = 0;
+
+/* Don't count to be released vcpu, might be not in vcpu list yet. */
+for_each_sched_unit_vcpu ( unit, vunit )
+if ( vunit != v )
+cnt++;
+
+v->sched_unit = NULL;
+unit->runstate_cnt[v->runstate.state]--;
+
+if ( unit->vcpu_list == v )
+unit->vcpu_list = v->next_in_list;
+
+if ( !cnt )
+sched_free_unit_mem(unit);
+}
+
+static void sched_unit_add_vcpu(struct sched_unit *unit, struct vcpu *v)
+{
+v->sched_unit = unit;
+
+/* All but idle vcpus are allocated with sequential vcpu_id. */
+if ( !unit->vcpu_list || unit->vcpu_list->vcpu_id > v->vcpu_id )
+{
+unit->vcpu_list = v;
+/*
+ * unit_id is always the same as lowest vcpu_id of unit.
+ * This is used for stopping for_each_sched_unit_vcpu() loop and in
+ * order to support cpupools with different granularities.
+ */
+unit->unit_id = v->vcpu_id;
+}
+unit->runstate_cnt[v->runstate.state]++;
+}
+
static struct sched_unit *sched_alloc_unit(struct vcpu *v)
{
struct sched_unit *unit, **prev_unit;
struct domain *d = v->domain;
+for_each_sched_unit ( d, unit )
+if ( unit->unit_id / sched_granularity ==
+ v->vcpu_id / sched_granularity )
+break;
+
+if ( unit )
+{
+sched_unit_add_vcpu(unit, v);
+return unit;
+}
+
if ( (unit = xzalloc(struct sched_unit)) == NULL )
return NULL;
-unit->vcpu_list = v;
-unit->unit_id = v->vcpu_id;
unit->domain = d;
-unit->runstate_cnt[v->runstate.state]++;
+sched_unit_add_vcpu(unit, v);
for ( prev_unit = >sched_unit_list; *prev_unit;
prev_unit = &(*prev_unit)->next_in_list )
@@ -402,12 +447,10 @@ static struct sched_unit *sched_alloc_unit(struct vcpu *v)
!zalloc_cpumask_var(>cpu_soft_affinity) )
goto fail;
-v->sched_unit = unit;
-
return unit;
fail:
-sched_free_unit(unit);
+sched_free_unit(unit, v);
return NULL;
}
@@ -457,21 +500,26 @@ int sched_init_vcpu(struct vcpu *v)
else
processor = sched_select_initial_cpu(v);
-sched_set_res(unit, get_sched_res(processor));
-
/* Initialise the per-vcpu timers. */
spin_lock_init(>periodic_timer_lock);
-init_timer(>periodic_timer, vcpu_periodic_timer_fn,
- v, v->processor);
-init_timer(>singleshot_timer, vcpu_singleshot_timer_fn,
- v, v->processor);
-init_timer(>poll_timer, poll_timer_fn,
- v, v->processor);
+init_timer(>periodic_timer, vcpu_periodic_timer_fn, v, processor);
+init_timer(>singleshot_timer, vcpu_singleshot_timer_fn, v, processor);
+init_timer(>poll_timer, poll_timer_fn, v, processor);
+
+/* If this is not the first vcpu of the unit we are done. */
+if ( unit->priv != NULL )
+{
+v->processor = processor;
+return 0;
+}
+
+/* The first vcpu of an unit can be set via sched_set_res(). */
+sched_set_res(unit, get_sched_res(processor));
unit->priv = sched_alloc_udata(dom_scheduler(d), unit, d->sched_priv);
if ( unit->priv == NULL )
{
-sched_free_unit(unit);
+sched_free_unit(unit, v);
return 1;
}
@@ -631,9 +679,16 @@ void sched_destroy_vcpu(struct vcpu *v)
