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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v4 21/46] xen/sched: use sched_resource cpu instead smp_processor_id in schedulers
Especially in the do_schedule() functions of the different schedulers
using smp_processor_id() for the local cpu number is correct only if
the sched_unit is a single vcpu. As soon as larger sched_units are
used most uses should be replaced by the master_cpu number of the local
sched_resource instead.
Add a helper to get that sched_resource master_cpu and modify the
schedulers to use it in a correct way.
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Dario Faggioli <dfaggioli@xxxxxxxx>
---
V3:
- style correction (Jan Beulich)
- rename cpu to cur_cpu when introducing sched_cpu in same function
(Jan Beulich)
- undo change in sched_idle_schedule() (Jan Beulich)
V4:
- simplify test for correct cpu (Jan Beulich)
---
xen/common/sched_arinc653.c | 2 +-
xen/common/sched_credit.c | 23 ++++++++++---------
xen/common/sched_credit2.c | 55 +++++++++++++++++++++++----------------------
xen/common/sched_null.c | 25 +++++++++++----------
xen/common/sched_rt.c | 19 ++++++++--------
xen/include/xen/sched-if.h | 5 +++++
6 files changed, 69 insertions(+), 60 deletions(-)
diff --git a/xen/common/sched_arinc653.c b/xen/common/sched_arinc653.c
index f04d9c9cb1..2bc187c92b 100644
--- a/xen/common/sched_arinc653.c
+++ b/xen/common/sched_arinc653.c
@@ -519,7 +519,7 @@ a653sched_do_schedule(
static unsigned int sched_index = 0;
static s_time_t next_switch_time;
a653sched_priv_t *sched_priv = SCHED_PRIV(ops);
- const unsigned int cpu = smp_processor_id();
+ const unsigned int cpu = sched_get_resource_cpu(smp_processor_id());
unsigned long flags;
spin_lock_irqsave(&sched_priv->lock, flags);
diff --git a/xen/common/sched_credit.c b/xen/common/sched_credit.c
index 21c3a033b9..7f6ba35766 100644
--- a/xen/common/sched_credit.c
+++ b/xen/common/sched_credit.c
@@ -1684,7 +1684,7 @@ csched_load_balance(struct csched_private *prv, int cpu,
int peer_cpu, first_cpu, peer_node, bstep;
int node = cpu_to_node(cpu);
- BUG_ON( cpu != sched_unit_master(snext->unit) );
+ BUG_ON(get_sched_res(cpu) != snext->unit->res);
online = cpupool_online_cpumask(c);
/*
@@ -1825,8 +1825,9 @@ static struct task_slice
csched_schedule(
const struct scheduler *ops, s_time_t now, bool_t tasklet_work_scheduled)
{
- const int cpu = smp_processor_id();
- struct list_head * const runq = RUNQ(cpu);
+ const unsigned int cur_cpu = smp_processor_id();
+ const unsigned int sched_cpu = sched_get_resource_cpu(cur_cpu);
+ struct list_head * const runq = RUNQ(sched_cpu);
struct sched_unit *unit = current->sched_unit;
struct csched_unit * const scurr = CSCHED_UNIT(unit);
struct csched_private *prv = CSCHED_PRIV(ops);
@@ -1847,7 +1848,7 @@ csched_schedule(
struct {
unsigned cpu:16, tasklet:8, idle:8;
} d;
- d.cpu = cpu;
+ d.cpu = cur_cpu;
d.tasklet = tasklet_work_scheduled;
d.idle = is_idle_unit(unit);
__trace_var(TRC_CSCHED_SCHEDULE, 1, sizeof(d),
@@ -1937,7 +1938,7 @@ csched_schedule(
{
BUG_ON( is_idle_unit(unit) || list_empty(runq) );
/* Current has blocked. Update the runnable counter for this cpu. */
- dec_nr_runnable(cpu);
+ dec_nr_runnable(sched_cpu);
}
snext = __runq_elem(runq->next);
@@ -1947,7 +1948,7 @@ csched_schedule(
if ( tasklet_work_scheduled )
{
TRACE_0D(TRC_CSCHED_SCHED_TASKLET);
- snext = CSCHED_UNIT(sched_idle_unit(cpu));
+ snext = CSCHED_UNIT(sched_idle_unit(sched_cpu));
snext->pri = CSCHED_PRI_TS_BOOST;
}
@@ -1967,7 +1968,7 @@ csched_schedule(
if ( snext->pri > CSCHED_PRI_TS_OVER )
__runq_remove(snext);
else
- snext = csched_load_balance(prv, cpu, snext, &ret.migrated);
+ snext = csched_load_balance(prv, sched_cpu, snext, &ret.migrated);
/*
* Update idlers mask if necessary. When we're idling, other CPUs
@@ -1975,12 +1976,12 @@ csched_schedule(
*/
if ( !tasklet_work_scheduled && snext->pri == CSCHED_PRI_IDLE )
{
- if ( !cpumask_test_cpu(cpu, prv->idlers) )
- cpumask_set_cpu(cpu, prv->idlers);
+ if ( !cpumask_test_cpu(sched_cpu, prv->idlers) )
+ cpumask_set_cpu(sched_cpu, prv->idlers);
}
- else if ( cpumask_test_cpu(cpu, prv->idlers) )
+ else if ( cpumask_test_cpu(sched_cpu, prv->idlers) )
{
- cpumask_clear_cpu(cpu, prv->idlers);
+ cpumask_clear_cpu(sched_cpu, prv->idlers);
}
if ( !is_idle_unit(snext->unit) )
diff --git a/xen/common/sched_credit2.c b/xen/common/sched_credit2.c
index 3ee76323df..c4c6c69a0e 100644
--- a/xen/common/sched_credit2.c
+++ b/xen/common/sched_credit2.c
@@ -3450,7 +3450,8 @@ static struct task_slice
csched2_schedule(
const struct scheduler *ops, s_time_t now, bool tasklet_work_scheduled)
{
- const int cpu = smp_processor_id();
+ const unsigned int cur_cpu = smp_processor_id();
+ const unsigned int sched_cpu = sched_get_resource_cpu(cur_cpu);
struct csched2_runqueue_data *rqd;
struct sched_unit *currunit = current->sched_unit;
struct csched2_unit * const scurr = csched2_unit(currunit);
@@ -3462,22 +3463,22 @@ csched2_schedule(
SCHED_STAT_CRANK(schedule);
CSCHED2_UNIT_CHECK(currunit);
- BUG_ON(!cpumask_test_cpu(cpu, &csched2_priv(ops)->initialized));
+ BUG_ON(!cpumask_test_cpu(sched_cpu, &csched2_priv(ops)->initialized));
- rqd = c2rqd(ops, cpu);
- BUG_ON(!cpumask_test_cpu(cpu, &rqd->active));
+ rqd = c2rqd(ops, sched_cpu);
+ BUG_ON(!cpumask_test_cpu(sched_cpu, &rqd->active));
- ASSERT(spin_is_locked(get_sched_res(cpu)->schedule_lock));
+ ASSERT(spin_is_locked(get_sched_res(sched_cpu)->schedule_lock));
BUG_ON(!is_idle_unit(currunit) && scurr->rqd != rqd);
/* Clear "tickled" bit now that we've been scheduled */
- tickled = cpumask_test_cpu(cpu, &rqd->tickled);
+ tickled = cpumask_test_cpu(sched_cpu, &rqd->tickled);
if ( tickled )
{
- __cpumask_clear_cpu(cpu, &rqd->tickled);
+ __cpumask_clear_cpu(sched_cpu, &rqd->tickled);
cpumask_andnot(cpumask_scratch, &rqd->idle, &rqd->tickled);
- smt_idle_mask_set(cpu, cpumask_scratch, &rqd->smt_idle);
+ smt_idle_mask_set(sched_cpu, cpumask_scratch, &rqd->smt_idle);
}
if ( unlikely(tb_init_done) )
@@ -3486,11 +3487,11 @@ csched2_schedule(
unsigned cpu:16, rq_id:16;
unsigned tasklet:8, idle:8, smt_idle:8, tickled:8;
} d;
- d.cpu = cpu;
- d.rq_id = c2r(cpu);
+ d.cpu = cur_cpu;
+ d.rq_id = c2r(sched_cpu);
d.tasklet = tasklet_work_scheduled;
d.idle = is_idle_unit(currunit);
- d.smt_idle = cpumask_test_cpu(cpu, &rqd->smt_idle);
+ d.smt_idle = cpumask_test_cpu(sched_cpu, &rqd->smt_idle);
d.tickled = tickled;
__trace_var(TRC_CSCHED2_SCHEDULE, 1,
sizeof(d),
@@ -3530,10 +3531,10 @@ csched2_schedule(
{
__clear_bit(__CSFLAG_unit_yield, &scurr->flags);
trace_var(TRC_CSCHED2_SCHED_TASKLET, 1, 0, NULL);
- snext = csched2_unit(sched_idle_unit(cpu));
+ snext = csched2_unit(sched_idle_unit(sched_cpu));
}
else
- snext = runq_candidate(rqd, scurr, cpu, now, &skipped_units);
+ snext = runq_candidate(rqd, scurr, sched_cpu, now, &skipped_units);
/* If switching from a non-idle runnable unit, put it
* back on the runqueue. */
@@ -3558,10 +3559,10 @@ csched2_schedule(
}
/* Clear the idle mask if necessary */
- if ( cpumask_test_cpu(cpu, &rqd->idle) )
+ if ( cpumask_test_cpu(sched_cpu, &rqd->idle) )
{
- __cpumask_clear_cpu(cpu, &rqd->idle);
- smt_idle_mask_clear(cpu, &rqd->smt_idle);
+ __cpumask_clear_cpu(sched_cpu, &rqd->idle);
+ smt_idle_mask_clear(sched_cpu, &rqd->smt_idle);
}
/*
@@ -3580,18 +3581,18 @@ csched2_schedule(
*/
if ( skipped_units == 0 && snext->credit <= CSCHED2_CREDIT_RESET )
{
- reset_credit(ops, cpu, now, snext);
- balance_load(ops, cpu, now);
+ reset_credit(ops, sched_cpu, now, snext);
+ balance_load(ops, sched_cpu, now);
}
snext->start_time = now;
snext->tickled_cpu = -1;
/* Safe because lock for old processor is held */
- if ( sched_unit_master(snext->unit) != cpu )
+ if ( sched_unit_master(snext->unit) != sched_cpu )
{
snext->credit += CSCHED2_MIGRATE_COMPENSATION;
- sched_set_res(snext->unit, get_sched_res(cpu));
+ sched_set_res(snext->unit, get_sched_res(sched_cpu));
SCHED_STAT_CRANK(migrated);
ret.migrated = 1;
}
@@ -3604,17 +3605,17 @@ csched2_schedule(
*/
if ( tasklet_work_scheduled )
{
- if ( cpumask_test_cpu(cpu, &rqd->idle) )
+ if ( cpumask_test_cpu(sched_cpu, &rqd->idle) )
{
- __cpumask_clear_cpu(cpu, &rqd->idle);
- smt_idle_mask_clear(cpu, &rqd->smt_idle);
+ __cpumask_clear_cpu(sched_cpu, &rqd->idle);
+ smt_idle_mask_clear(sched_cpu, &rqd->smt_idle);
}
}
- else if ( !cpumask_test_cpu(cpu, &rqd->idle) )
+ else if ( !cpumask_test_cpu(sched_cpu, &rqd->idle) )
{
- __cpumask_set_cpu(cpu, &rqd->idle);
+ __cpumask_set_cpu(sched_cpu, &rqd->idle);
cpumask_andnot(cpumask_scratch, &rqd->idle, &rqd->tickled);
- smt_idle_mask_set(cpu, cpumask_scratch, &rqd->smt_idle);
+ smt_idle_mask_set(sched_cpu, cpumask_scratch, &rqd->smt_idle);
}
/* Make sure avgload gets updated periodically even
* if there's no activity */
@@ -3624,7 +3625,7 @@ csched2_schedule(
/*
* Return task to run next...
*/
- ret.time = csched2_runtime(ops, cpu, snext, now);
+ ret.time = csched2_runtime(ops, sched_cpu, snext, now);
ret.task = snext->unit;
CSCHED2_UNIT_CHECK(ret.task);
diff --git a/xen/common/sched_null.c b/xen/common/sched_null.c
index 4c9eed81ae..51edc3dbb9 100644
--- a/xen/common/sched_null.c
+++ b/xen/common/sched_null.c
@@ -784,7 +784,8 @@ static struct task_slice null_schedule(const struct
scheduler *ops,
bool_t tasklet_work_scheduled)
{
unsigned int bs;
- const unsigned int cpu = smp_processor_id();
+ const unsigned int cur_cpu = smp_processor_id();
+ const unsigned int sched_cpu = sched_get_resource_cpu(cur_cpu);
struct null_private *prv = null_priv(ops);
struct null_unit *wvc;
struct task_slice ret;
@@ -798,16 +799,16 @@ static struct task_slice null_schedule(const struct
scheduler *ops,
uint16_t tasklet, cpu;
int16_t unit, dom;
} d;
- d.cpu = cpu;
+ d.cpu = cur_cpu;
d.tasklet = tasklet_work_scheduled;
- if ( per_cpu(npc, cpu).unit == NULL )
+ if ( per_cpu(npc, sched_cpu).unit == NULL )
{
d.unit = d.dom = -1;
}
else
{
- d.unit = per_cpu(npc, cpu).unit->unit_id;
- d.dom = per_cpu(npc, cpu).unit->domain->domain_id;
+ d.unit = per_cpu(npc, sched_cpu).unit->unit_id;
+ d.dom = per_cpu(npc, sched_cpu).unit->domain->domain_id;
}
__trace_var(TRC_SNULL_SCHEDULE, 1, sizeof(d), &d);
}
@@ -815,10 +816,10 @@ static struct task_slice null_schedule(const struct
scheduler *ops,
if ( tasklet_work_scheduled )
{
trace_var(TRC_SNULL_TASKLET, 1, 0, NULL);
- ret.task = sched_idle_unit(cpu);
+ ret.task = sched_idle_unit(sched_cpu);
}
else
- ret.task = per_cpu(npc, cpu).unit;
+ ret.task = per_cpu(npc, sched_cpu).unit;
ret.migrated = 0;
ret.time = -1;
@@ -849,9 +850,9 @@ static struct task_slice null_schedule(const struct
scheduler *ops,
!has_soft_affinity(wvc->unit) )
continue;
- if ( unit_check_affinity(wvc->unit, cpu, bs) )
+ if ( unit_check_affinity(wvc->unit, sched_cpu, bs) )
{
- unit_assign(prv, wvc->unit, cpu);
+ unit_assign(prv, wvc->unit, sched_cpu);
list_del_init(&wvc->waitq_elem);
ret.task = wvc->unit;
goto unlock;
@@ -861,12 +862,12 @@ static struct task_slice null_schedule(const struct
scheduler *ops,
unlock:
spin_unlock(&prv->waitq_lock);
- if ( ret.task == NULL && !cpumask_test_cpu(cpu, &prv->cpus_free) )
- cpumask_set_cpu(cpu, &prv->cpus_free);
+ if ( ret.task == NULL && !cpumask_test_cpu(sched_cpu, &prv->cpus_free)
)
+ cpumask_set_cpu(sched_cpu, &prv->cpus_free);
}
if ( unlikely(ret.task == NULL || !unit_runnable(ret.task)) )
- ret.task = sched_idle_unit(cpu);
+ ret.task = sched_idle_unit(sched_cpu);
NULL_UNIT_CHECK(ret.task);
return ret;
diff --git a/xen/common/sched_rt.c b/xen/common/sched_rt.c
index 3e8852c348..151353b9a0 100644
--- a/xen/common/sched_rt.c
+++ b/xen/common/sched_rt.c
@@ -1056,7 +1056,8 @@ runq_pick(const struct scheduler *ops, const cpumask_t
*mask)
static struct task_slice
rt_schedule(const struct scheduler *ops, s_time_t now, bool_t
tasklet_work_scheduled)
{
- const int cpu = smp_processor_id();
+ const unsigned int cur_cpu = smp_processor_id();
+ const unsigned int sched_cpu = sched_get_resource_cpu(cur_cpu);
struct rt_private *prv = rt_priv(ops);
struct rt_unit *const scurr = rt_unit(current->sched_unit);
struct rt_unit *snext = NULL;
@@ -1068,9 +1069,9 @@ rt_schedule(const struct scheduler *ops, s_time_t now,
bool_t tasklet_work_sched
struct __packed {
unsigned cpu:16, tasklet:8, tickled:4, idle:4;
} d;
- d.cpu = cpu;
+ d.cpu = cur_cpu;
d.tasklet = tasklet_work_scheduled;
- d.tickled = cpumask_test_cpu(cpu, &prv->tickled);
+ d.tickled = cpumask_test_cpu(sched_cpu, &prv->tickled);
d.idle = is_idle_unit(currunit);
trace_var(TRC_RTDS_SCHEDULE, 1,
sizeof(d),
@@ -1078,7 +1079,7 @@ rt_schedule(const struct scheduler *ops, s_time_t now,
bool_t tasklet_work_sched
}
/* clear ticked bit now that we've been scheduled */
- cpumask_clear_cpu(cpu, &prv->tickled);
+ cpumask_clear_cpu(sched_cpu, &prv->tickled);
/* burn_budget would return for IDLE UNIT */
burn_budget(ops, scurr, now);
@@ -1086,13 +1087,13 @@ rt_schedule(const struct scheduler *ops, s_time_t now,
bool_t tasklet_work_sched
if ( tasklet_work_scheduled )
{
trace_var(TRC_RTDS_SCHED_TASKLET, 1, 0, NULL);
- snext = rt_unit(sched_idle_unit(cpu));
+ snext = rt_unit(sched_idle_unit(sched_cpu));
}
else
{
- snext = runq_pick(ops, cpumask_of(cpu));
+ snext = runq_pick(ops, cpumask_of(sched_cpu));
if ( snext == NULL )
- snext = rt_unit(sched_idle_unit(cpu));
+ snext = rt_unit(sched_idle_unit(sched_cpu));
/* if scurr has higher priority and budget, still pick scurr */
if ( !is_idle_unit(currunit) &&
@@ -1117,9 +1118,9 @@ rt_schedule(const struct scheduler *ops, s_time_t now,
bool_t tasklet_work_sched
q_remove(snext);
__set_bit(__RTDS_scheduled, &snext->flags);
}
- if ( sched_unit_master(snext->unit) != cpu )
+ if ( sched_unit_master(snext->unit) != sched_cpu )
{
- sched_set_res(snext->unit, get_sched_res(cpu));
+ sched_set_res(snext->unit, get_sched_res(sched_cpu));
ret.migrated = 1;
}
ret.time = snext->cur_budget; /* invoke the scheduler next time */
diff --git a/xen/include/xen/sched-if.h b/xen/include/xen/sched-if.h
index 4797ba3f2b..d7fad0cbcc 100644
--- a/xen/include/xen/sched-if.h
+++ b/xen/include/xen/sched-if.h
@@ -150,6 +150,11 @@ static inline struct sched_unit *sched_idle_unit(unsigned
int cpu)
return idle_vcpu[cpu]->sched_unit;
}
+static inline unsigned int sched_get_resource_cpu(unsigned int cpu)
+{
+ return get_sched_res(cpu)->master_cpu;
+}
+
/*
* Scratch space, for avoiding having too many cpumask_t on the stack.
* Within each scheduler, when using the scratch mask of one pCPU:
--
2.16.4
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