| Message ID | 20180613121711.5018-3-juri.lelli@redhat.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v4,1/5] sched/topology: Add check to backup comment about hotplug lock | expand |
On Wed, 13 Jun 2018 14:17:08 +0200 Juri Lelli <juri.lelli@redhat.com> wrote: > From: Mathieu Poirier <mathieu.poirier@linaro.org> > > Introducing function partition_sched_domains_locked() by taking > the mutex locking code out of the original function. That way > the work done by partition_sched_domains_locked() can be reused > without dropping the mutex lock. > > No change of functionality is introduced by this patch. > > Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> > --- > include/linux/sched/topology.h | 10 ++++++++++ > kernel/sched/topology.c | 18 ++++++++++++++---- > 2 files changed, 24 insertions(+), 4 deletions(-) > > diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h > index 26347741ba50..57997caf61b6 100644 > --- a/include/linux/sched/topology.h > +++ b/include/linux/sched/topology.h > @@ -162,6 +162,10 @@ static inline struct cpumask *sched_domain_span(struct sched_domain *sd) > return to_cpumask(sd->span); > } > > +extern void partition_sched_domains_locked(int ndoms_new, > + cpumask_var_t doms_new[], > + struct sched_domain_attr *dattr_new); > + > extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], > struct sched_domain_attr *dattr_new); > > @@ -206,6 +210,12 @@ extern void set_sched_topology(struct sched_domain_topology_level *tl); > > struct sched_domain_attr; > > +static inline void > +partition_sched_domains_locked(int ndoms_new, cpumask_var_t doms_new[], > + struct sched_domain_attr *dattr_new) > +{ > +} > + > static inline void > partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], > struct sched_domain_attr *dattr_new) > diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c > index 96eee22fafe8..25a5727d3b48 100644 > --- a/kernel/sched/topology.c > +++ b/kernel/sched/topology.c > @@ -1850,16 +1850,16 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, > * ndoms_new == 0 is a special case for destroying existing domains, > * and it will not create the default domain. > * > - * Call with hotplug lock held > + * Call with hotplug lock and sched_domains_mutex held > */ > -void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], > - struct sched_domain_attr *dattr_new) > +void partition_sched_domains_locked(int ndoms_new, cpumask_var_t doms_new[], > + struct sched_domain_attr *dattr_new) > { > int i, j, n; > int new_topology; > > lockdep_assert_cpus_held(); > - mutex_lock(&sched_domains_mutex); > + lockdep_assert_held(&sched_domains_mutex); > > /* Always unregister in case we don't destroy any domains: */ > unregister_sched_domain_sysctl(); > @@ -1924,6 +1924,16 @@ void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], > ndoms_cur = ndoms_new; > > register_sched_domain_sysctl(); > +} > > +/* > + * Call with hotplug lock held > + */ > +void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], > + struct sched_domain_attr *dattr_new) > +{ > + lockdep_assert_cpus_held(); Is the above assert really necessary? The assert will happen in partition_sched_domains_locked() anyway. -- Steve > + mutex_lock(&sched_domains_mutex); > + partition_sched_domains_locked(ndoms_new, doms_new, dattr_new); > mutex_unlock(&sched_domains_mutex); > }
On 14/06/18 09:35, Steven Rostedt wrote: > On Wed, 13 Jun 2018 14:17:08 +0200 > Juri Lelli <juri.lelli@redhat.com> wrote: [...] > > +/* > > + * Call with hotplug lock held > > + */ > > +void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], > > + struct sched_domain_attr *dattr_new) > > +{ > > + lockdep_assert_cpus_held(); > > Is the above assert really necessary? The assert will happen in > partition_sched_domains_locked() anyway. Indeed, it seems of little use. Thanks, - Juri
diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h index 26347741ba50..57997caf61b6 100644 --- a/include/linux/sched/topology.h +++ b/include/linux/sched/topology.h @@ -162,6 +162,10 @@ static inline struct cpumask *sched_domain_span(struct sched_domain *sd) return to_cpumask(sd->span); } +extern void partition_sched_domains_locked(int ndoms_new, + cpumask_var_t doms_new[], + struct sched_domain_attr *dattr_new); + extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], struct sched_domain_attr *dattr_new); @@ -206,6 +210,12 @@ extern void set_sched_topology(struct sched_domain_topology_level *tl); struct sched_domain_attr; +static inline void +partition_sched_domains_locked(int ndoms_new, cpumask_var_t doms_new[], + struct sched_domain_attr *dattr_new) +{ +} + static inline void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], struct sched_domain_attr *dattr_new) diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 96eee22fafe8..25a5727d3b48 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -1850,16 +1850,16 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, * ndoms_new == 0 is a special case for destroying existing domains, * and it will not create the default domain. * - * Call with hotplug lock held + * Call with hotplug lock and sched_domains_mutex held */ -void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], - struct sched_domain_attr *dattr_new) +void partition_sched_domains_locked(int ndoms_new, cpumask_var_t doms_new[], + struct sched_domain_attr *dattr_new) { int i, j, n; int new_topology; lockdep_assert_cpus_held(); - mutex_lock(&sched_domains_mutex); + lockdep_assert_held(&sched_domains_mutex); /* Always unregister in case we don't destroy any domains: */ unregister_sched_domain_sysctl(); @@ -1924,6 +1924,16 @@ void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], ndoms_cur = ndoms_new; register_sched_domain_sysctl(); +} +/* + * Call with hotplug lock held + */ +void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], + struct sched_domain_attr *dattr_new) +{ + lockdep_assert_cpus_held(); + mutex_lock(&sched_domains_mutex); + partition_sched_domains_locked(ndoms_new, doms_new, dattr_new); mutex_unlock(&sched_domains_mutex); }