diff options
Diffstat (limited to 'kernel/sched/sched.h')
| -rw-r--r-- | kernel/sched/sched.h | 48 |
1 files changed, 39 insertions, 9 deletions
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index be9745d104f7..1f5d07067f60 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -365,25 +365,50 @@ extern s64 dl_scaled_delta_exec(struct rq *rq, struct sched_dl_entity *dl_se, s6 * * dl_se::rq -- runqueue we belong to. * - * dl_se::server_has_tasks() -- used on bandwidth enforcement; we 'stop' the - * server when it runs out of tasks to run. - * * dl_se::server_pick() -- nested pick_next_task(); we yield the period if this * returns NULL. * * dl_server_update() -- called from update_curr_common(), propagates runtime * to the server. * - * dl_server_start() - * dl_server_stop() -- start/stop the server when it has (no) tasks. + * dl_server_start() -- start the server when it has tasks; it will stop + * automatically when there are no more tasks, per + * dl_se::server_pick() returning NULL. + * + * dl_server_stop() -- (force) stop the server; use when updating + * parameters. * * dl_server_init() -- initializes the server. + * + * When started the dl_server will (per dl_defer) schedule a timer for its + * zero-laxity point -- that is, unlike regular EDF tasks which run ASAP, a + * server will run at the very end of its period. + * + * This is done such that any runtime from the target class can be accounted + * against the server -- through dl_server_update() above -- such that when it + * becomes time to run, it might already be out of runtime and get deferred + * until the next period. In this case dl_server_timer() will alternate + * between defer and replenish but never actually enqueue the server. + * + * Only when the target class does not manage to exhaust the server's runtime + * (there's actualy starvation in the given period), will the dl_server get on + * the runqueue. Once queued it will pick tasks from the target class and run + * them until either its runtime is exhaused, at which point its back to + * dl_server_timer, or until there are no more tasks to run, at which point + * the dl_server stops itself. + * + * By stopping at this point the dl_server retains bandwidth, which, if a new + * task wakes up imminently (starting the server again), can be used -- + * subject to CBS wakeup rules -- without having to wait for the next period. + * + * Additionally, because of the dl_defer behaviour the start/stop behaviour is + * naturally thottled to once per period, avoiding high context switch + * workloads from spamming the hrtimer program/cancel paths. */ extern void dl_server_update(struct sched_dl_entity *dl_se, s64 delta_exec); extern void dl_server_start(struct sched_dl_entity *dl_se); extern void dl_server_stop(struct sched_dl_entity *dl_se); extern void dl_server_init(struct sched_dl_entity *dl_se, struct rq *rq, - dl_server_has_tasks_f has_tasks, dl_server_pick_f pick_task); extern void sched_init_dl_servers(void); @@ -735,10 +760,12 @@ struct cfs_rq { u64 throttled_clock_pelt_time; u64 throttled_clock_self; u64 throttled_clock_self_time; - int throttled; + bool throttled:1; + bool pelt_clock_throttled:1; int throttle_count; struct list_head throttled_list; struct list_head throttled_csd_list; + struct list_head throttled_limbo_list; #endif /* CONFIG_CFS_BANDWIDTH */ #endif /* CONFIG_FAIR_GROUP_SCHED */ }; @@ -1935,12 +1962,12 @@ extern void sched_setnuma(struct task_struct *p, int node); extern int migrate_task_to(struct task_struct *p, int cpu); extern int migrate_swap(struct task_struct *p, struct task_struct *t, int cpu, int scpu); -extern void init_numa_balancing(unsigned long clone_flags, struct task_struct *p); +extern void init_numa_balancing(u64 clone_flags, struct task_struct *p); #else /* !CONFIG_NUMA_BALANCING: */ static inline void -init_numa_balancing(unsigned long clone_flags, struct task_struct *p) +init_numa_balancing(u64 clone_flags, struct task_struct *p) { } @@ -2342,6 +2369,7 @@ extern const u32 sched_prio_to_wmult[40]; #define DEQUEUE_SPECIAL 0x10 #define DEQUEUE_MIGRATING 0x100 /* Matches ENQUEUE_MIGRATING */ #define DEQUEUE_DELAYED 0x200 /* Matches ENQUEUE_DELAYED */ +#define DEQUEUE_THROTTLE 0x800 #define ENQUEUE_WAKEUP 0x01 #define ENQUEUE_RESTORE 0x02 @@ -2658,6 +2686,8 @@ extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq); extern void init_dl_entity(struct sched_dl_entity *dl_se); +extern void init_cfs_throttle_work(struct task_struct *p); + #define BW_SHIFT 20 #define BW_UNIT (1 << BW_SHIFT) #define RATIO_SHIFT 8 |