@@ -151,6 +151,7 @@ struct vcpu *vcpu_create(struct domain *d, unsigned int vcpu_id)
if ( is_idle_domain(d) )
{
v->runstate.state = RUNSTATE_running;
+ v->new_state = RUNSTATE_running;
}
else
{
@@ -557,7 +557,7 @@ a653sched_do_schedule(
if ( !((new_task != NULL)
&& (AITEM(new_task) != NULL)
&& AITEM(new_task)->awake
- && item_runnable(new_task)) )
+ && item_runnable_state(new_task)) )
new_task = IDLETASK(cpu);
BUG_ON(new_task == NULL);
@@ -1907,7 +1907,7 @@ static void csched_schedule(
if ( !test_bit(CSCHED_FLAG_ITEM_YIELD, &scurr->flags)
&& !tasklet_work_scheduled
&& prv->ratelimit
- && item_runnable(item)
+ && item_runnable_state(item)
&& !is_idle_item(item)
&& runtime < prv->ratelimit )
{
@@ -1952,33 +1952,36 @@ static void csched_schedule(
dec_nr_runnable(sched_cpu);
}
- snext = __runq_elem(runq->next);
-
- /* Tasklet work (which runs in idle ITEM context) overrides all else. */
- if ( tasklet_work_scheduled )
- {
- TRACE_0D(TRC_CSCHED_SCHED_TASKLET);
- snext = CSCHED_ITEM(sched_idle_item(sched_cpu));
- snext->pri = CSCHED_PRI_TS_BOOST;
- }
-
/*
* Clear YIELD flag before scheduling out
*/
clear_bit(CSCHED_FLAG_ITEM_YIELD, &scurr->flags);
- /*
- * SMP Load balance:
- *
- * If the next highest priority local runnable ITEM has already eaten
- * through its credits, look on other PCPUs to see if we have more
- * urgent work... If not, csched_load_balance() will return snext, but
- * already removed from the runq.
- */
- if ( snext->pri > CSCHED_PRI_TS_OVER )
- __runq_remove(snext);
- else
- snext = csched_load_balance(prv, sched_cpu, snext, &migrated);
+ do {
+ snext = __runq_elem(runq->next);
+
+ /* Tasklet work (which runs in idle ITEM context) overrides all else. */
+ if ( tasklet_work_scheduled )
+ {
+ TRACE_0D(TRC_CSCHED_SCHED_TASKLET);
+ snext = CSCHED_ITEM(sched_idle_item(sched_cpu));
+ snext->pri = CSCHED_PRI_TS_BOOST;
+ }
+
+ /*
+ * SMP Load balance:
+ *
+ * If the next highest priority local runnable ITEM has already eaten
+ * through its credits, look on other PCPUs to see if we have more
+ * urgent work... If not, csched_load_balance() will return snext, but
+ * already removed from the runq.
+ */
+ if ( snext->pri > CSCHED_PRI_TS_OVER )
+ __runq_remove(snext);
+ else
+ snext = csched_load_balance(prv, sched_cpu, snext, &migrated);
+
+ } while ( !item_runnable_state(snext->item) );
/*
* Update idlers mask if necessary. When we're idling, other CPUs
@@ -3288,7 +3288,7 @@ runq_candidate(struct csched2_runqueue_data *rqd,
* In fact, it may be the case that scurr is about to spin, and there's
* no point forcing it to do so until rate limiting expires.
*/
- if ( !yield && prv->ratelimit_us && item_runnable(scurr->item) &&
+ if ( !yield && prv->ratelimit_us && item_runnable_state(scurr->item) &&
(now - scurr->item->state_entry_time) < MICROSECS(prv->ratelimit_us) )
{
if ( unlikely(tb_init_done) )
@@ -3342,7 +3342,7 @@ runq_candidate(struct csched2_runqueue_data *rqd,
*
* Of course, we also default to idle also if scurr is not runnable.
*/
- if ( item_runnable(scurr->item) && !soft_aff_preempt )
+ if ( item_runnable_state(scurr->item) && !soft_aff_preempt )
snext = scurr;
else
snext = csched2_item(sched_idle_item(cpu));
@@ -3402,7 +3402,8 @@ runq_candidate(struct csched2_runqueue_data *rqd,
* some budget, then choose it.
*/
if ( (yield || svc->credit > snext->credit) &&
- (!has_cap(svc) || item_grab_budget(svc)) )
+ (!has_cap(svc) || item_grab_budget(svc)) &&
+ item_runnable_state(svc->item) )
snext = svc;
/* In any case, if we got this far, break. */
@@ -784,7 +784,8 @@ static void null_schedule(const struct scheduler *ops, struct sched_item *prev,
spin_unlock(&prv->waitq_lock);
}
- if ( unlikely(prev->next_task == NULL || !item_runnable(prev->next_task)) )
+ if ( unlikely(prev->next_task == NULL ||
+ !item_runnable_state(prev->next_task)) )
prev->next_task = sched_idle_item(sched_cpu);
NULL_ITEM_CHECK(prev->next_task);
@@ -1101,12 +1101,18 @@ rt_schedule(const struct scheduler *ops, struct sched_item *curritem,
else
{
snext = runq_pick(ops, cpumask_of(sched_cpu));
+
if ( snext == NULL )
snext = rt_item(sched_idle_item(sched_cpu));
+ else if ( !item_runnable_state(snext->item) )
+ {
+ q_remove(snext);
+ snext = rt_item(sched_idle_item(sched_cpu));
+ }
/* if scurr has higher priority and budget, still pick scurr */
if ( !is_idle_item(curritem) &&
- item_runnable(curritem) &&
+ item_runnable_state(curritem) &&
scurr->cur_budget > 0 &&
( is_idle_item(snext->item) ||
compare_item_priority(scurr, snext) > 0 ) )
@@ -206,7 +206,7 @@ static inline void sched_item_runstate_change(struct sched_item *item,
struct vcpu *v = item->vcpu;
if ( running )
- vcpu_runstate_change(v, RUNSTATE_running, new_entry_time);
+ vcpu_runstate_change(v, v->new_state, new_entry_time);
else
vcpu_runstate_change(v,
((v->pause_flags & VPF_blocked) ? RUNSTATE_blocked :
@@ -60,6 +60,20 @@ static inline bool item_runnable(const struct sched_item *item)
return vcpu_runnable(item->vcpu);
}
+static inline bool item_runnable_state(const struct sched_item *item)
+{
+ struct vcpu *v;
+ bool runnable;
+
+ v = item->vcpu;
+ runnable = vcpu_runnable(v);
+
+ v->new_state = runnable ? RUNSTATE_running
+ : (v->pause_flags & VPF_blocked)
+ ? RUNSTATE_blocked : RUNSTATE_offline;
+ return runnable;
+}
+
static inline void sched_set_res(struct sched_item *item,
struct sched_resource *res)
{
@@ -174,6 +174,7 @@ struct vcpu
XEN_GUEST_HANDLE(vcpu_runstate_info_compat_t) compat;
} runstate_guest; /* guest address */
#endif
+ int new_state;
/* Has the FPU been initialised? */
bool fpu_initialised;
Today the vcpu runstate of a new scheduled vcpu is always set to "running" even if at that time vcpu_runnable() is already returning false due to a race (e.g. with pausing the vcpu). With core scheduling this can no longer work as not all vcpus of a schedule item have to be "running" when being scheduled. So the vcpu's new runstate has to be selected at the same time as the runnability of the related schedule item is probed. For this purpose introduce a new helper item_runnable_state() which will save the new runstate of all tested vcpus in a new field of the vcpu struct. Signed-off-by: Juergen Gross <jgross@suse.com> --- RFC V2: new patch --- xen/common/domain.c | 1 + xen/common/sched_arinc653.c | 2 +- xen/common/sched_credit.c | 49 ++++++++++++++++++++++++--------------------- xen/common/sched_credit2.c | 7 ++++--- xen/common/sched_null.c | 3 ++- xen/common/sched_rt.c | 8 +++++++- xen/common/schedule.c | 2 +- xen/include/xen/sched-if.h | 14 +++++++++++++ xen/include/xen/sched.h | 1 + 9 files changed, 57 insertions(+), 30 deletions(-)