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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v4 13/46] xen/sched: add is_running indicator to struct sched_unit
Add an is_running indicator to struct sched_unit which will be set
whenever the unit is being scheduled. Switch scheduler code to use
unit->is_running instead of vcpu->is_running for scheduling decisions.
At the same time introduce a state_entry_time field in struct
sched_unit being updated whenever the is_running indicator is changed.
Use that new field in the schedulers instead of the similar vcpu field.
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Dario Faggioli <dfaggioli@xxxxxxxx>
---
RFC V2:
- fix arm build, don't drop v->is_running
V3:
- avoid holes in structures (Jan Beulich)
V4:
- assign true/false to boolean instead of 1/0 (Jan Beulich)
---
xen/common/sched_credit.c | 12 +++++++-----
xen/common/sched_credit2.c | 18 +++++++++---------
xen/common/sched_rt.c | 2 +-
xen/common/schedule.c | 13 ++++++++++---
xen/include/xen/sched.h | 6 ++++++
5 files changed, 33 insertions(+), 18 deletions(-)
diff --git a/xen/common/sched_credit.c b/xen/common/sched_credit.c
index 732fd461b5..9404ccfd90 100644
--- a/xen/common/sched_credit.c
+++ b/xen/common/sched_credit.c
@@ -709,7 +709,7 @@ __csched_vcpu_is_migrateable(const struct csched_private
*prv, struct vcpu *vc,
* The caller is supposed to have already checked that vc is also
* not running.
*/
- ASSERT(!vc->is_running);
+ ASSERT(!vc->sched_unit->is_running);
return !__csched_vcpu_is_cache_hot(prv, svc) &&
cpumask_test_cpu(dest_cpu, mask);
@@ -1033,7 +1033,8 @@ csched_unit_insert(const struct scheduler *ops, struct
sched_unit *unit)
lock = unit_schedule_lock_irq(unit);
- if ( !__vcpu_on_runq(svc) && vcpu_runnable(vc) && !vc->is_running )
+ if ( !__vcpu_on_runq(svc) && vcpu_runnable(vc) &&
+ !vc->sched_unit->is_running )
runq_insert(svc);
unit_schedule_unlock_irq(lock, unit);
@@ -1646,8 +1647,9 @@ csched_runq_steal(int peer_cpu, int cpu, int pri, int
balance_step)
* vCPUs with useful soft affinities in some sort of bitmap
* or counter.
*/
- if ( vc->is_running || (balance_step == BALANCE_SOFT_AFFINITY &&
- !has_soft_affinity(vc->sched_unit)) )
+ if ( vc->sched_unit->is_running ||
+ (balance_step == BALANCE_SOFT_AFFINITY &&
+ !has_soft_affinity(vc->sched_unit)) )
continue;
affinity_balance_cpumask(vc->sched_unit, balance_step,
cpumask_scratch);
@@ -1855,7 +1857,7 @@ csched_schedule(
(unsigned char *)&d);
}
- runtime = now - current->runstate.state_entry_time;
+ runtime = now - current->sched_unit->state_entry_time;
if ( runtime < 0 ) /* Does this ever happen? */
runtime = 0;
diff --git a/xen/common/sched_credit2.c b/xen/common/sched_credit2.c
index 8857c98dd8..7ec61a2649 100644
--- a/xen/common/sched_credit2.c
+++ b/xen/common/sched_credit2.c
@@ -1284,7 +1284,7 @@ runq_insert(const struct scheduler *ops, struct
csched2_unit *svc)
ASSERT(&svc->rqd->runq == runq);
ASSERT(!is_idle_vcpu(svc->vcpu));
- ASSERT(!svc->vcpu->is_running);
+ ASSERT(!svc->vcpu->sched_unit->is_running);
ASSERT(!(svc->flags & CSFLAG_scheduled));
list_for_each( iter, runq )
@@ -1341,8 +1341,8 @@ static inline bool is_preemptable(const struct
csched2_unit *svc,
if ( ratelimit <= CSCHED2_RATELIMIT_TICKLE_TOLERANCE )
return true;
- ASSERT(svc->vcpu->is_running);
- return now - svc->vcpu->runstate.state_entry_time >
+ ASSERT(svc->vcpu->sched_unit->is_running);
+ return now - svc->vcpu->sched_unit->state_entry_time >
ratelimit - CSCHED2_RATELIMIT_TICKLE_TOLERANCE;
}
@@ -2932,7 +2932,7 @@ csched2_dom_cntl(
{
svc = csched2_unit(v->sched_unit);
lock = unit_schedule_lock(svc->vcpu->sched_unit);
- if ( v->is_running )
+ if ( v->sched_unit->is_running )
{
unsigned int cpu = v->processor;
struct csched2_runqueue_data *rqd = c2rqd(ops, cpu);
@@ -3205,8 +3205,8 @@ csched2_runtime(const struct scheduler *ops, int cpu,
if ( prv->ratelimit_us )
{
s_time_t ratelimit_min = MICROSECS(prv->ratelimit_us);
- if ( snext->vcpu->is_running )
- ratelimit_min = snext->vcpu->runstate.state_entry_time +
+ if ( snext->vcpu->sched_unit->is_running )
+ ratelimit_min = snext->vcpu->sched_unit->state_entry_time +
MICROSECS(prv->ratelimit_us) - now;
if ( ratelimit_min > min_time )
min_time = ratelimit_min;
@@ -3303,7 +3303,7 @@ runq_candidate(struct csched2_runqueue_data *rqd,
* no point forcing it to do so until rate limiting expires.
*/
if ( !yield && prv->ratelimit_us && vcpu_runnable(scurr->vcpu) &&
- (now - scurr->vcpu->runstate.state_entry_time) <
+ (now - scurr->vcpu->sched_unit->state_entry_time) <
MICROSECS(prv->ratelimit_us) )
{
if ( unlikely(tb_init_done) )
@@ -3314,7 +3314,7 @@ runq_candidate(struct csched2_runqueue_data *rqd,
} d;
d.dom = scurr->vcpu->domain->domain_id;
d.vcpu = scurr->vcpu->vcpu_id;
- d.runtime = now - scurr->vcpu->runstate.state_entry_time;
+ d.runtime = now - scurr->vcpu->sched_unit->state_entry_time;
__trace_var(TRC_CSCHED2_RATELIMIT, 1,
sizeof(d),
(unsigned char *)&d);
@@ -3562,7 +3562,7 @@ csched2_schedule(
if ( snext != scurr )
{
ASSERT(snext->rqd == rqd);
- ASSERT(!snext->vcpu->is_running);
+ ASSERT(!snext->vcpu->sched_unit->is_running);
runq_remove(snext);
__set_bit(__CSFLAG_scheduled, &snext->flags);
diff --git a/xen/common/sched_rt.c b/xen/common/sched_rt.c
index 856eae1faa..13e0d754ab 100644
--- a/xen/common/sched_rt.c
+++ b/xen/common/sched_rt.c
@@ -905,7 +905,7 @@ rt_unit_insert(const struct scheduler *ops, struct
sched_unit *unit)
{
replq_insert(ops, svc);
- if ( !vc->is_running )
+ if ( !unit->is_running )
runq_insert(ops, svc);
}
unit_schedule_unlock_irq(lock, unit);
diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index 157b91c439..b027c084bf 100644
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -412,6 +412,8 @@ int sched_init_vcpu(struct vcpu *v, unsigned int processor)
{
get_sched_res(v->processor)->curr = unit;
v->is_running = 1;
+ unit->is_running = true;
+ unit->state_entry_time = NOW();
}
else
{
@@ -732,7 +734,8 @@ static void vcpu_migrate_finish(struct vcpu *v)
* context_saved(); and in any case, if the bit is cleared, then
* someone else has already done the work so we don't need to.
*/
- if ( v->is_running || !test_bit(_VPF_migrating, &v->pause_flags) )
+ if ( v->sched_unit->is_running ||
+ !test_bit(_VPF_migrating, &v->pause_flags) )
return;
old_cpu = new_cpu = v->processor;
@@ -786,7 +789,7 @@ static void vcpu_migrate_finish(struct vcpu *v)
* because they both happen in (different) spinlock regions, and those
* regions are strictly serialised.
*/
- if ( v->is_running ||
+ if ( v->sched_unit->is_running ||
!test_and_clear_bit(_VPF_migrating, &v->pause_flags) )
{
sched_spin_unlock_double(old_lock, new_lock, flags);
@@ -1674,8 +1677,10 @@ static void schedule(void)
* switch, else lost_records resume will not work properly.
*/
- ASSERT(!next->is_running);
+ ASSERT(!next->sched_unit->is_running);
next->is_running = 1;
+ next->sched_unit->is_running = true;
+ next->sched_unit->state_entry_time = now;
pcpu_schedule_unlock_irq(lock, cpu);
@@ -1697,6 +1702,8 @@ void context_saved(struct vcpu *prev)
smp_wmb();
prev->is_running = 0;
+ prev->sched_unit->is_running = false;
+ prev->sched_unit->state_entry_time = NOW();
/* Check for migration request /after/ clearing running flag. */
smp_mb();
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 3227d2fe71..5646d620c3 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -270,8 +270,14 @@ struct sched_unit {
struct sched_resource *res;
unsigned int unit_id;
+ /* Currently running on a CPU? */
+ bool is_running;
/* Does soft affinity actually play a role (given hard affinity)? */
bool soft_aff_effective;
+
+ /* Last time unit got (de-)scheduled. */
+ uint64_t state_entry_time;
+
/* Bitmask of CPUs on which this VCPU may run. */
cpumask_var_t cpu_hard_affinity;
/* Used to save affinity during temporary pinning. */
--
2.16.4
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