diff options
Diffstat (limited to 'kernel/sched_autogroup.c')
| -rw-r--r-- | kernel/sched_autogroup.c | 41 |
1 files changed, 39 insertions, 2 deletions
diff --git a/kernel/sched_autogroup.c b/kernel/sched_autogroup.c index 32a723b8f84..429242f3c48 100644 --- a/kernel/sched_autogroup.c +++ b/kernel/sched_autogroup.c @@ -12,7 +12,6 @@ static atomic_t autogroup_seq_nr; static void __init autogroup_init(struct task_struct *init_task) { autogroup_default.tg = &root_task_group; - root_task_group.autogroup = &autogroup_default; kref_init(&autogroup_default.kref); init_rwsem(&autogroup_default.lock); init_task->signal->autogroup = &autogroup_default; @@ -27,6 +26,11 @@ static inline void autogroup_destroy(struct kref *kref) { struct autogroup *ag = container_of(kref, struct autogroup, kref); +#ifdef CONFIG_RT_GROUP_SCHED + /* We've redirected RT tasks to the root task group... */ + ag->tg->rt_se = NULL; + ag->tg->rt_rq = NULL; +#endif sched_destroy_group(ag->tg); } @@ -55,6 +59,10 @@ static inline struct autogroup *autogroup_task_get(struct task_struct *p) return ag; } +#ifdef CONFIG_RT_GROUP_SCHED +static void free_rt_sched_group(struct task_group *tg); +#endif + static inline struct autogroup *autogroup_create(void) { struct autogroup *ag = kzalloc(sizeof(*ag), GFP_KERNEL); @@ -72,6 +80,19 @@ static inline struct autogroup *autogroup_create(void) init_rwsem(&ag->lock); ag->id = atomic_inc_return(&autogroup_seq_nr); ag->tg = tg; +#ifdef CONFIG_RT_GROUP_SCHED + /* + * Autogroup RT tasks are redirected to the root task group + * so we don't have to move tasks around upon policy change, + * or flail around trying to allocate bandwidth on the fly. + * A bandwidth exception in __sched_setscheduler() allows + * the policy change to proceed. Thereafter, task_group() + * returns &root_task_group, so zero bandwidth is required. + */ + free_rt_sched_group(tg); + tg->rt_se = root_task_group.rt_se; + tg->rt_rq = root_task_group.rt_rq; +#endif tg->autogroup = ag; return ag; @@ -106,6 +127,11 @@ task_wants_autogroup(struct task_struct *p, struct task_group *tg) return true; } +static inline bool task_group_is_autogroup(struct task_group *tg) +{ + return !!tg->autogroup; +} + static inline struct task_group * autogroup_task_group(struct task_struct *p, struct task_group *tg) { @@ -134,11 +160,15 @@ autogroup_move_group(struct task_struct *p, struct autogroup *ag) p->signal->autogroup = autogroup_kref_get(ag); + if (!ACCESS_ONCE(sysctl_sched_autogroup_enabled)) + goto out; + t = p; do { sched_move_task(t); } while_each_thread(p, t); +out: unlock_task_sighand(p, &flags); autogroup_kref_put(prev); } @@ -149,7 +179,7 @@ void sched_autogroup_create_attach(struct task_struct *p) struct autogroup *ag = autogroup_create(); autogroup_move_group(p, ag); - /* drop extra refrence added by autogroup_create() */ + /* drop extra reference added by autogroup_create() */ autogroup_kref_put(ag); } EXPORT_SYMBOL(sched_autogroup_create_attach); @@ -220,10 +250,14 @@ void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m) { struct autogroup *ag = autogroup_task_get(p); + if (!task_group_is_autogroup(ag->tg)) + goto out; + down_read(&ag->lock); seq_printf(m, "/autogroup-%ld nice %d\n", ag->id, ag->nice); up_read(&ag->lock); +out: autogroup_kref_put(ag); } #endif /* CONFIG_PROC_FS */ @@ -231,6 +265,9 @@ void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m) #ifdef CONFIG_SCHED_DEBUG static inline int autogroup_path(struct task_group *tg, char *buf, int buflen) { + if (!task_group_is_autogroup(tg)) + return 0; + return snprintf(buf, buflen, "%s-%ld", "/autogroup", tg->autogroup->id); } #endif /* CONFIG_SCHED_DEBUG */ |