From: Steven Rostedt <rostedt@goodmis.org>
To: Juri Lelli <juri.lelli@redhat.com>
Cc: peterz@infradead.org, mingo@redhat.com,
linux-kernel@vger.kernel.org, luca.abeni@santannapisa.it,
claudio@evidence.eu.com, tommaso.cucinotta@santannapisa.it,
bristot@redhat.com, mathieu.poirier@linaro.org,
lizefan@huawei.com, cgroups@vger.kernel.org
Subject: Re: [PATCH v4 2/5] sched/topology: Adding function partition_sched_domains_locked()
Date: Thu, 14 Jun 2018 09:35:36 -0400 [thread overview]
Message-ID: <20180614093536.612712f6@gandalf.local.home> (raw)
In-Reply-To: <20180613121711.5018-3-juri.lelli@redhat.com>
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);
> }
next prev parent reply other threads:[~2018-06-14 13:35 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-13 12:17 [PATCH v4 0/5] sched/deadline: fix cpusets bandwidth accounting Juri Lelli
2018-06-13 12:17 ` [PATCH v4 1/5] sched/topology: Add check to backup comment about hotplug lock Juri Lelli
2018-06-14 13:33 ` Steven Rostedt
2018-06-14 13:42 ` Juri Lelli
2018-06-14 13:47 ` Steven Rostedt
2018-06-14 13:50 ` Juri Lelli
2018-06-14 13:58 ` Quentin Perret
2018-06-14 14:11 ` Juri Lelli
2018-06-14 14:18 ` Quentin Perret
2018-06-14 14:30 ` Juri Lelli
2018-06-15 8:39 ` Quentin Perret
2018-06-13 12:17 ` [PATCH v4 2/5] sched/topology: Adding function partition_sched_domains_locked() Juri Lelli
2018-06-14 13:35 ` Steven Rostedt [this message]
2018-06-14 13:47 ` Juri Lelli
2018-06-13 12:17 ` [PATCH v4 3/5] sched/core: Streamlining calls to task_rq_unlock() Juri Lelli
2018-06-14 13:42 ` Steven Rostedt
2018-06-13 12:17 ` [PATCH v4 4/5] sched/core: Prevent race condition between cpuset and __sched_setscheduler() Juri Lelli
2018-06-14 13:45 ` Steven Rostedt
2018-06-14 13:51 ` Juri Lelli
2018-06-14 20:11 ` Steven Rostedt
2018-06-15 7:01 ` Juri Lelli
2018-06-15 13:07 ` Juri Lelli
2018-06-13 12:17 ` [PATCH v4 5/5] cpuset: Rebuild root domain deadline accounting information Juri Lelli
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