diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index cab5fd1ee767..f7efa7b4d825 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -812,18 +812,6 @@ done: return ndoms; } -static void cpuset_sched_change_begin(void) -{ - cpus_read_lock(); - mutex_lock(&cpuset_mutex); -} - -static void cpuset_sched_change_end(void) -{ - mutex_unlock(&cpuset_mutex); - cpus_read_unlock(); -} - /* * Rebuild scheduler domains. * @@ -833,14 +821,16 @@ static void cpuset_sched_change_end(void) * 'cpus' is removed, then call this routine to rebuild the * scheduler's dynamic sched domains. * + * Call with cpuset_mutex held. Takes get_online_cpus(). */ -static void rebuild_sched_domains_cpuslocked(void) +static void rebuild_sched_domains_locked(void) { struct sched_domain_attr *attr; cpumask_var_t *doms; int ndoms; lockdep_assert_held(&cpuset_mutex); + get_online_cpus(); /* * We have raced with CPU hotplug. Don't do anything to avoid @@ -848,25 +838,27 @@ static void rebuild_sched_domains_cpuslocked(void) * Anyways, hotplug work item will rebuild sched domains. */ if (!cpumask_equal(top_cpuset.effective_cpus, cpu_active_mask)) - return; + goto out; /* Generate domain masks and attrs */ ndoms = generate_sched_domains(&doms, &attr); /* Have scheduler rebuild the domains */ partition_sched_domains(ndoms, doms, attr); +out: + put_online_cpus(); } #else /* !CONFIG_SMP */ -static void rebuild_sched_domains_cpuslocked(void) +static void rebuild_sched_domains_locked(void) { } #endif /* CONFIG_SMP */ void rebuild_sched_domains(void) { - cpuset_sched_change_begin(); - rebuild_sched_domains_cpuslocked(); - cpuset_sched_change_end(); + mutex_lock(&cpuset_mutex); + rebuild_sched_domains_locked(); + mutex_unlock(&cpuset_mutex); } /** @@ -952,7 +944,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct cpumask *new_cpus) rcu_read_unlock(); if (need_rebuild_sched_domains) - rebuild_sched_domains_cpuslocked(); + rebuild_sched_domains_locked(); } /** @@ -1284,7 +1276,7 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val) cs->relax_domain_level = val; if (!cpumask_empty(cs->cpus_allowed) && is_sched_load_balance(cs)) - rebuild_sched_domains_cpuslocked(); + rebuild_sched_domains_locked(); } return 0; @@ -1317,6 +1309,7 @@ static void update_tasks_flags(struct cpuset *cs) * * Call with cpuset_mutex held. */ + static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, int turning_on) { @@ -1349,7 +1342,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, spin_unlock_irq(&callback_lock); if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed) - rebuild_sched_domains_cpuslocked(); + rebuild_sched_domains_locked(); if (spread_flag_changed) update_tasks_flags(cs); @@ -1617,7 +1610,7 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft, cpuset_filetype_t type = cft->private; int retval = 0; - cpuset_sched_change_begin(); + mutex_lock(&cpuset_mutex); if (!is_cpuset_online(cs)) { retval = -ENODEV; goto out_unlock; @@ -1653,7 +1646,7 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft, break; } out_unlock: - cpuset_sched_change_end(); + mutex_unlock(&cpuset_mutex); return retval; } @@ -1664,7 +1657,7 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft, cpuset_filetype_t type = cft->private; int retval = -ENODEV; - cpuset_sched_change_begin(); + mutex_lock(&cpuset_mutex); if (!is_cpuset_online(cs)) goto out_unlock; @@ -1677,7 +1670,7 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft, break; } out_unlock: - cpuset_sched_change_end(); + mutex_unlock(&cpuset_mutex); return retval; } @@ -1716,7 +1709,7 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of, kernfs_break_active_protection(of->kn); flush_work(&cpuset_hotplug_work); - cpuset_sched_change_begin(); + mutex_lock(&cpuset_mutex); if (!is_cpuset_online(cs)) goto out_unlock; @@ -1740,7 +1733,7 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of, free_trial_cpuset(trialcs); out_unlock: - cpuset_sched_change_end(); + mutex_unlock(&cpuset_mutex); kernfs_unbreak_active_protection(of->kn); css_put(&cs->css); flush_workqueue(cpuset_migrate_mm_wq); @@ -2041,14 +2034,14 @@ out_unlock: /* * If the cpuset being removed has its flag 'sched_load_balance' * enabled, then simulate turning sched_load_balance off, which - * will call rebuild_sched_domains_cpuslocked(). + * will call rebuild_sched_domains_locked(). */ static void cpuset_css_offline(struct cgroup_subsys_state *css) { struct cpuset *cs = css_cs(css); - cpuset_sched_change_begin(); + mutex_lock(&cpuset_mutex); if (is_sched_load_balance(cs)) update_flag(CS_SCHED_LOAD_BALANCE, cs, 0); @@ -2056,7 +2049,7 @@ static void cpuset_css_offline(struct cgroup_subsys_state *css) cpuset_dec(); clear_bit(CS_ONLINE, &cs->flags); - cpuset_sched_change_end(); + mutex_unlock(&cpuset_mutex); } static void cpuset_css_free(struct cgroup_subsys_state *css)