rcu: Add funnel-locking tracing for expedited grace periods

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney 2016-01-28 20:30:06 -08:00
parent e087816db9
commit bea2de44ae
2 changed files with 30 additions and 4 deletions

View file

@ -3584,10 +3584,18 @@ static bool sync_exp_work_done(struct rcu_state *rsp, struct rcu_node *rnp,
atomic_long_t *stat, unsigned long s)
{
if (rcu_exp_gp_seq_done(rsp, s)) {
if (rnp)
if (rnp) {
mutex_unlock(&rnp->exp_funnel_mutex);
else if (rdp)
trace_rcu_exp_funnel_lock(rsp->name, rnp->level,
rnp->grplo, rnp->grphi,
TPS("rel"));
} else if (rdp) {
mutex_unlock(&rdp->exp_funnel_mutex);
trace_rcu_exp_funnel_lock(rsp->name,
rdp->mynode->level + 1,
rdp->cpu, rdp->cpu,
TPS("rel"));
}
/* Ensure test happens before caller kfree(). */
smp_mb__before_atomic(); /* ^^^ */
atomic_long_inc(stat);
@ -3619,6 +3627,9 @@ static struct rcu_node *exp_funnel_lock(struct rcu_state *rsp, unsigned long s)
if (sync_exp_work_done(rsp, rnp0, NULL,
&rdp->expedited_workdone0, s))
return NULL;
trace_rcu_exp_funnel_lock(rsp->name, rnp0->level,
rnp0->grplo, rnp0->grphi,
TPS("acq"));
return rnp0;
}
}
@ -3634,16 +3645,28 @@ static struct rcu_node *exp_funnel_lock(struct rcu_state *rsp, unsigned long s)
if (sync_exp_work_done(rsp, NULL, NULL, &rdp->expedited_workdone1, s))
return NULL;
mutex_lock(&rdp->exp_funnel_mutex);
trace_rcu_exp_funnel_lock(rsp->name, rdp->mynode->level + 1,
rdp->cpu, rdp->cpu, TPS("acq"));
rnp0 = rdp->mynode;
for (; rnp0 != NULL; rnp0 = rnp0->parent) {
if (sync_exp_work_done(rsp, rnp1, rdp,
&rdp->expedited_workdone2, s))
return NULL;
mutex_lock(&rnp0->exp_funnel_mutex);
if (rnp1)
trace_rcu_exp_funnel_lock(rsp->name, rnp0->level,
rnp0->grplo, rnp0->grphi, TPS("acq"));
if (rnp1) {
mutex_unlock(&rnp1->exp_funnel_mutex);
else
trace_rcu_exp_funnel_lock(rsp->name, rnp1->level,
rnp1->grplo, rnp1->grphi,
TPS("rel"));
} else {
mutex_unlock(&rdp->exp_funnel_mutex);
trace_rcu_exp_funnel_lock(rsp->name,
rdp->mynode->level + 1,
rdp->cpu, rdp->cpu,
TPS("rel"));
}
rnp1 = rnp0;
}
if (sync_exp_work_done(rsp, rnp1, rdp,

View file

@ -767,6 +767,9 @@ void synchronize_rcu_expedited(void)
/* Clean up and exit. */
rcu_exp_gp_seq_end(rsp);
mutex_unlock(&rnp_unlock->exp_funnel_mutex);
trace_rcu_exp_funnel_lock(rsp->name, rnp_unlock->level,
rnp_unlock->grplo, rnp_unlock->grphi,
TPS("rel"));
}
EXPORT_SYMBOL_GPL(synchronize_rcu_expedited);