diff options
Diffstat (limited to 'block/bfq-iosched.h')
| -rw-r--r-- | block/bfq-iosched.h | 51 |
1 files changed, 33 insertions, 18 deletions
diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index 63e771ab56d8..ac0809c72c98 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -71,17 +71,29 @@ struct bfq_service_tree { * * bfq_sched_data is the basic scheduler queue. It supports three * ioprio_classes, and can be used either as a toplevel queue or as an - * intermediate queue on a hierarchical setup. @next_in_service - * points to the active entity of the sched_data service trees that - * will be scheduled next. It is used to reduce the number of steps - * needed for each hierarchical-schedule update. + * intermediate queue in a hierarchical setup. * * The supported ioprio_classes are the same as in CFQ, in descending * priority order, IOPRIO_CLASS_RT, IOPRIO_CLASS_BE, IOPRIO_CLASS_IDLE. * Requests from higher priority queues are served before all the * requests from lower priority queues; among requests of the same * queue requests are served according to B-WF2Q+. - * All the fields are protected by the queue lock of the containing bfqd. + * + * The schedule is implemented by the service trees, plus the field + * @next_in_service, which points to the entity on the active trees + * that will be served next, if 1) no changes in the schedule occurs + * before the current in-service entity is expired, 2) the in-service + * queue becomes idle when it expires, and 3) if the entity pointed by + * in_service_entity is not a queue, then the in-service child entity + * of the entity pointed by in_service_entity becomes idle on + * expiration. This peculiar definition allows for the following + * optimization, not yet exploited: while a given entity is still in + * service, we already know which is the best candidate for next + * service among the other active entitities in the same parent + * entity. We can then quickly compare the timestamps of the + * in-service entity with those of such best candidate. + * + * All fields are protected by the lock of the containing bfqd. */ struct bfq_sched_data { /* entity in service */ @@ -348,11 +360,11 @@ struct bfq_io_cq { uint64_t blkcg_serial_nr; /* the current blkcg serial */ #endif /* - * Snapshot of the idle window before merging; taken to - * remember this value while the queue is merged, so as to be - * able to restore it in case of split. + * Snapshot of the has_short_time flag before merging; taken + * to remember its value while the queue is merged, so as to + * be able to restore it in case of split. */ - bool saved_idle_window; + bool saved_has_short_ttime; /* * Same purpose as the previous two fields for the I/O bound * classification of a queue. @@ -626,7 +638,7 @@ enum bfqq_state_flags { * without idling the device */ BFQQF_fifo_expire, /* FIFO checked in this slice */ - BFQQF_idle_window, /* slice idling enabled */ + BFQQF_has_short_ttime, /* queue has a short think time */ BFQQF_sync, /* synchronous queue */ BFQQF_IO_bound, /* * bfqq has timed-out at least once @@ -655,7 +667,7 @@ BFQ_BFQQ_FNS(busy); BFQ_BFQQ_FNS(wait_request); BFQ_BFQQ_FNS(non_blocking_wait_rq); BFQ_BFQQ_FNS(fifo_expire); -BFQ_BFQQ_FNS(idle_window); +BFQ_BFQQ_FNS(has_short_ttime); BFQ_BFQQ_FNS(sync); BFQ_BFQQ_FNS(IO_bound); BFQ_BFQQ_FNS(in_large_burst); @@ -805,7 +817,6 @@ extern const int bfq_timeout; struct bfq_queue *bic_to_bfqq(struct bfq_io_cq *bic, bool is_sync); void bic_set_bfqq(struct bfq_io_cq *bic, struct bfq_queue *bfqq, bool is_sync); struct bfq_data *bic_to_bfqd(struct bfq_io_cq *bic); -void bfq_requeue_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq); void bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq); void bfq_weights_tree_add(struct bfq_data *bfqd, struct bfq_entity *entity, struct rb_root *root); @@ -905,7 +916,8 @@ void __bfq_bfqd_reset_in_service(struct bfq_data *bfqd); void bfq_deactivate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq, bool ins_into_idle_tree, bool expiration); void bfq_activate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq); -void bfq_requeue_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq); +void bfq_requeue_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq, + bool expiration); void bfq_del_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq, bool expiration); void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq); @@ -917,13 +929,16 @@ void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq); struct bfq_group *bfqq_group(struct bfq_queue *bfqq); #define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do { \ - blk_add_trace_msg((bfqd)->queue, "bfq%d%c %s " fmt, (bfqq)->pid,\ - bfq_bfqq_sync((bfqq)) ? 'S' : 'A', \ - bfqq_group(bfqq)->blkg_path, ##args); \ + blk_add_cgroup_trace_msg((bfqd)->queue, \ + bfqg_to_blkg(bfqq_group(bfqq))->blkcg, \ + "bfq%d%c " fmt, (bfqq)->pid, \ + bfq_bfqq_sync((bfqq)) ? 'S' : 'A', ##args); \ } while (0) -#define bfq_log_bfqg(bfqd, bfqg, fmt, args...) \ - blk_add_trace_msg((bfqd)->queue, "%s " fmt, (bfqg)->blkg_path, ##args) +#define bfq_log_bfqg(bfqd, bfqg, fmt, args...) do { \ + blk_add_cgroup_trace_msg((bfqd)->queue, \ + bfqg_to_blkg(bfqg)->blkcg, fmt, ##args); \ +} while (0) #else /* CONFIG_BFQ_GROUP_IOSCHED */ |