diff options
Diffstat (limited to 'kernel/cgroup/cpuset.c')
| -rw-r--r-- | kernel/cgroup/cpuset.c | 163 |
1 files changed, 125 insertions, 38 deletions
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 5aa37531ce76..c52bc91f882b 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -45,6 +45,7 @@ #include <linux/proc_fs.h> #include <linux/rcupdate.h> #include <linux/sched.h> +#include <linux/sched/deadline.h> #include <linux/sched/mm.h> #include <linux/sched/task.h> #include <linux/seq_file.h> @@ -332,7 +333,18 @@ static struct cpuset top_cpuset = { * guidelines for accessing subsystem state in kernel/cgroup.c */ -static DEFINE_MUTEX(cpuset_mutex); +DEFINE_STATIC_PERCPU_RWSEM(cpuset_rwsem); + +void cpuset_read_lock(void) +{ + percpu_down_read(&cpuset_rwsem); +} + +void cpuset_read_unlock(void) +{ + percpu_up_read(&cpuset_rwsem); +} + static DEFINE_SPINLOCK(callback_lock); static struct workqueue_struct *cpuset_migrate_mm_wq; @@ -894,6 +906,67 @@ done: return ndoms; } +static void update_tasks_root_domain(struct cpuset *cs) +{ + struct css_task_iter it; + struct task_struct *task; + + css_task_iter_start(&cs->css, 0, &it); + + while ((task = css_task_iter_next(&it))) + dl_add_task_root_domain(task); + + css_task_iter_end(&it); +} + +static void rebuild_root_domains(void) +{ + struct cpuset *cs = NULL; + struct cgroup_subsys_state *pos_css; + + percpu_rwsem_assert_held(&cpuset_rwsem); + lockdep_assert_cpus_held(); + lockdep_assert_held(&sched_domains_mutex); + + cgroup_enable_task_cg_lists(); + + rcu_read_lock(); + + /* + * Clear default root domain DL accounting, it will be computed again + * if a task belongs to it. + */ + dl_clear_root_domain(&def_root_domain); + + cpuset_for_each_descendant_pre(cs, pos_css, &top_cpuset) { + + if (cpumask_empty(cs->effective_cpus)) { + pos_css = css_rightmost_descendant(pos_css); + continue; + } + + css_get(&cs->css); + + rcu_read_unlock(); + + update_tasks_root_domain(cs); + + rcu_read_lock(); + css_put(&cs->css); + } + rcu_read_unlock(); +} + +static void +partition_and_rebuild_sched_domains(int ndoms_new, cpumask_var_t doms_new[], + struct sched_domain_attr *dattr_new) +{ + mutex_lock(&sched_domains_mutex); + partition_sched_domains_locked(ndoms_new, doms_new, dattr_new); + rebuild_root_domains(); + mutex_unlock(&sched_domains_mutex); +} + /* * Rebuild scheduler domains. * @@ -911,8 +984,8 @@ static void rebuild_sched_domains_locked(void) cpumask_var_t *doms; int ndoms; - lockdep_assert_held(&cpuset_mutex); - get_online_cpus(); + lockdep_assert_cpus_held(); + percpu_rwsem_assert_held(&cpuset_rwsem); /* * We have raced with CPU hotplug. Don't do anything to avoid @@ -921,19 +994,17 @@ static void rebuild_sched_domains_locked(void) */ if (!top_cpuset.nr_subparts_cpus && !cpumask_equal(top_cpuset.effective_cpus, cpu_active_mask)) - goto out; + return; if (top_cpuset.nr_subparts_cpus && !cpumask_subset(top_cpuset.effective_cpus, cpu_active_mask)) - goto out; + return; /* 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(); + partition_and_rebuild_sched_domains(ndoms, doms, attr); } #else /* !CONFIG_SMP */ static void rebuild_sched_domains_locked(void) @@ -943,9 +1014,11 @@ static void rebuild_sched_domains_locked(void) void rebuild_sched_domains(void) { - mutex_lock(&cpuset_mutex); + get_online_cpus(); + percpu_down_write(&cpuset_rwsem); rebuild_sched_domains_locked(); - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); + put_online_cpus(); } /** @@ -1051,7 +1124,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd, int deleting; /* Moving cpus from subparts_cpus to effective_cpus */ bool part_error = false; /* Partition error? */ - lockdep_assert_held(&cpuset_mutex); + percpu_rwsem_assert_held(&cpuset_rwsem); /* * The parent must be a partition root. @@ -2039,7 +2112,7 @@ static int cpuset_can_attach(struct cgroup_taskset *tset) cpuset_attach_old_cs = task_cs(cgroup_taskset_first(tset, &css)); cs = css_cs(css); - mutex_lock(&cpuset_mutex); + percpu_down_write(&cpuset_rwsem); /* allow moving tasks into an empty cpuset if on default hierarchy */ ret = -ENOSPC; @@ -2063,7 +2136,7 @@ static int cpuset_can_attach(struct cgroup_taskset *tset) cs->attach_in_progress++; ret = 0; out_unlock: - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); return ret; } @@ -2073,9 +2146,9 @@ static void cpuset_cancel_attach(struct cgroup_taskset *tset) cgroup_taskset_first(tset, &css); - mutex_lock(&cpuset_mutex); + percpu_down_write(&cpuset_rwsem); css_cs(css)->attach_in_progress--; - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); } /* @@ -2098,7 +2171,7 @@ static void cpuset_attach(struct cgroup_taskset *tset) cgroup_taskset_first(tset, &css); cs = css_cs(css); - mutex_lock(&cpuset_mutex); + percpu_down_write(&cpuset_rwsem); /* prepare for attach */ if (cs == &top_cpuset) @@ -2152,7 +2225,7 @@ static void cpuset_attach(struct cgroup_taskset *tset) if (!cs->attach_in_progress) wake_up(&cpuset_attach_wq); - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); } /* The various types of files and directories in a cpuset file system */ @@ -2183,7 +2256,8 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft, cpuset_filetype_t type = cft->private; int retval = 0; - mutex_lock(&cpuset_mutex); + get_online_cpus(); + percpu_down_write(&cpuset_rwsem); if (!is_cpuset_online(cs)) { retval = -ENODEV; goto out_unlock; @@ -2219,7 +2293,8 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft, break; } out_unlock: - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); + put_online_cpus(); return retval; } @@ -2230,7 +2305,8 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft, cpuset_filetype_t type = cft->private; int retval = -ENODEV; - mutex_lock(&cpuset_mutex); + get_online_cpus(); + percpu_down_write(&cpuset_rwsem); if (!is_cpuset_online(cs)) goto out_unlock; @@ -2243,7 +2319,8 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft, break; } out_unlock: - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); + put_online_cpus(); return retval; } @@ -2282,7 +2359,8 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of, kernfs_break_active_protection(of->kn); flush_work(&cpuset_hotplug_work); - mutex_lock(&cpuset_mutex); + get_online_cpus(); + percpu_down_write(&cpuset_rwsem); if (!is_cpuset_online(cs)) goto out_unlock; @@ -2306,7 +2384,8 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of, free_cpuset(trialcs); out_unlock: - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); + put_online_cpus(); kernfs_unbreak_active_protection(of->kn); css_put(&cs->css); flush_workqueue(cpuset_migrate_mm_wq); @@ -2437,13 +2516,15 @@ static ssize_t sched_partition_write(struct kernfs_open_file *of, char *buf, return -EINVAL; css_get(&cs->css); - mutex_lock(&cpuset_mutex); + get_online_cpus(); + percpu_down_write(&cpuset_rwsem); if (!is_cpuset_online(cs)) goto out_unlock; retval = update_prstate(cs, val); out_unlock: - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); + put_online_cpus(); css_put(&cs->css); return retval ?: nbytes; } @@ -2649,7 +2730,8 @@ static int cpuset_css_online(struct cgroup_subsys_state *css) if (!parent) return 0; - mutex_lock(&cpuset_mutex); + get_online_cpus(); + percpu_down_write(&cpuset_rwsem); set_bit(CS_ONLINE, &cs->flags); if (is_spread_page(parent)) @@ -2700,7 +2782,8 @@ static int cpuset_css_online(struct cgroup_subsys_state *css) cpumask_copy(cs->effective_cpus, parent->cpus_allowed); spin_unlock_irq(&callback_lock); out_unlock: - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); + put_online_cpus(); return 0; } @@ -2719,7 +2802,8 @@ static void cpuset_css_offline(struct cgroup_subsys_state *css) { struct cpuset *cs = css_cs(css); - mutex_lock(&cpuset_mutex); + get_online_cpus(); + percpu_down_write(&cpuset_rwsem); if (is_partition_root(cs)) update_prstate(cs, 0); @@ -2738,7 +2822,8 @@ static void cpuset_css_offline(struct cgroup_subsys_state *css) cpuset_dec(); clear_bit(CS_ONLINE, &cs->flags); - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); + put_online_cpus(); } static void cpuset_css_free(struct cgroup_subsys_state *css) @@ -2750,7 +2835,7 @@ static void cpuset_css_free(struct cgroup_subsys_state *css) static void cpuset_bind(struct cgroup_subsys_state *root_css) { - mutex_lock(&cpuset_mutex); + percpu_down_write(&cpuset_rwsem); spin_lock_irq(&callback_lock); if (is_in_v2_mode()) { @@ -2763,7 +2848,7 @@ static void cpuset_bind(struct cgroup_subsys_state *root_css) } spin_unlock_irq(&callback_lock); - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); } /* @@ -2805,6 +2890,8 @@ struct cgroup_subsys cpuset_cgrp_subsys = { int __init cpuset_init(void) { + BUG_ON(percpu_init_rwsem(&cpuset_rwsem)); + BUG_ON(!alloc_cpumask_var(&top_cpuset.cpus_allowed, GFP_KERNEL)); BUG_ON(!alloc_cpumask_var(&top_cpuset.effective_cpus, GFP_KERNEL)); BUG_ON(!zalloc_cpumask_var(&top_cpuset.subparts_cpus, GFP_KERNEL)); @@ -2876,7 +2963,7 @@ hotplug_update_tasks_legacy(struct cpuset *cs, is_empty = cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed); - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); /* * Move tasks to the nearest ancestor with execution resources, @@ -2886,7 +2973,7 @@ hotplug_update_tasks_legacy(struct cpuset *cs, if (is_empty) remove_tasks_in_empty_cpuset(cs); - mutex_lock(&cpuset_mutex); + percpu_down_write(&cpuset_rwsem); } static void @@ -2936,14 +3023,14 @@ static void cpuset_hotplug_update_tasks(struct cpuset *cs, struct tmpmasks *tmp) retry: wait_event(cpuset_attach_wq, cs->attach_in_progress == 0); - mutex_lock(&cpuset_mutex); + percpu_down_write(&cpuset_rwsem); /* * We have raced with task attaching. We wait until attaching * is finished, so we won't attach a task to an empty cpuset. */ if (cs->attach_in_progress) { - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); goto retry; } @@ -3011,7 +3098,7 @@ update_tasks: hotplug_update_tasks_legacy(cs, &new_cpus, &new_mems, cpus_updated, mems_updated); - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); } /** @@ -3041,7 +3128,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work) if (on_dfl && !alloc_cpumasks(NULL, &tmp)) ptmp = &tmp; - mutex_lock(&cpuset_mutex); + percpu_down_write(&cpuset_rwsem); /* fetch the available cpus/mems and find out which changed how */ cpumask_copy(&new_cpus, cpu_active_mask); @@ -3091,7 +3178,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work) update_tasks_nodemask(&top_cpuset); } - mutex_unlock(&cpuset_mutex); + percpu_up_write(&cpuset_rwsem); /* if cpus or mems changed, we need to propagate to descendants */ if (cpus_updated || mems_updated) { |