diff options
Diffstat (limited to 'block/bfq-iosched.h')
| -rw-r--r-- | block/bfq-iosched.h | 107 |
1 files changed, 65 insertions, 42 deletions
diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index 86394e503ca9..c2faa77824f8 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -1,16 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Header file for the BFQ I/O scheduler: data structures and * prototypes of interface functions among BFQ components. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation; either version 2 of the - * License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. */ #ifndef _BFQ_H #define _BFQ_H @@ -32,6 +23,8 @@ #define BFQ_DEFAULT_GRP_IOPRIO 0 #define BFQ_DEFAULT_GRP_CLASS IOPRIO_CLASS_BE +#define MAX_PID_STR_LENGTH 12 + /* * Soft real-time applications are extremely more latency sensitive * than interactive ones. Over-raise the weight of the former to @@ -89,7 +82,7 @@ struct bfq_service_tree { * 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 + * service among the other active entities in the same parent * entity. We can then quickly compare the timestamps of the * in-service entity with those of such best candidate. * @@ -140,7 +133,7 @@ struct bfq_weight_counter { * * Unless cgroups are used, the weight value is calculated from the * ioprio to export the same interface as CFQ. When dealing with - * ``well-behaved'' queues (i.e., queues that do not spend too much + * "well-behaved" queues (i.e., queues that do not spend too much * time to consume their budget and have true sequential behavior, and * when there are no external factors breaking anticipation) the * relative weights at each level of the cgroups hierarchy should be @@ -240,6 +233,13 @@ struct bfq_queue { /* next ioprio and ioprio class if a change is in progress */ unsigned short new_ioprio, new_ioprio_class; + /* last total-service-time sample, see bfq_update_inject_limit() */ + u64 last_serv_time_ns; + /* limit for request injection */ + unsigned int inject_limit; + /* last time the inject limit has been decreased, in jiffies */ + unsigned long decrease_time_jif; + /* * Shared bfq_queue if queue is cooperating with one or more * other queues. @@ -357,29 +357,6 @@ struct bfq_queue { /* max service rate measured so far */ u32 max_service_rate; - /* - * Ratio between the service received by bfqq while it is in - * service, and the cumulative service (of requests of other - * queues) that may be injected while bfqq is empty but still - * in service. To increase precision, the coefficient is - * measured in tenths of unit. Here are some example of (1) - * ratios, (2) resulting percentages of service injected - * w.r.t. to the total service dispatched while bfqq is in - * service, and (3) corresponding values of the coefficient: - * 1 (50%) -> 10 - * 2 (33%) -> 20 - * 10 (9%) -> 100 - * 9.9 (9%) -> 99 - * 1.5 (40%) -> 15 - * 0.5 (66%) -> 5 - * 0.1 (90%) -> 1 - * - * So, if the coefficient is lower than 10, then - * injected service is more than bfqq service. - */ - unsigned int inject_coeff; - /* amount of service injected in current service slot */ - unsigned int injected_service; }; /** @@ -419,6 +396,15 @@ struct bfq_io_cq { bool was_in_burst_list; /* + * Save the weight when a merge occurs, to be able + * to restore it in case of split. If the weight is not + * correctly resumed when the queue is recycled, + * then the weight of the recycled queue could differ + * from the weight of the original queue. + */ + unsigned int saved_weight; + + /* * Similar to previous fields: save wr information. */ unsigned long saved_wr_coeff; @@ -450,7 +436,7 @@ struct bfq_data { * weight-raised @bfq_queue (see the comments to the functions * bfq_weights_tree_[add|remove] for further details). */ - struct rb_root queue_weights_tree; + struct rb_root_cached queue_weights_tree; /* * Number of groups with at least one descendant process that @@ -513,6 +499,9 @@ struct bfq_data { /* number of requests dispatched and waiting for completion */ int rq_in_driver; + /* true if the device is non rotational and performs queueing */ + bool nonrot_with_queueing; + /* * Maximum number of requests in driver in the last * @hw_tag_samples completed requests. @@ -544,6 +533,26 @@ struct bfq_data { /* time of last request completion (ns) */ u64 last_completion; + /* time of last transition from empty to non-empty (ns) */ + u64 last_empty_occupied_ns; + + /* + * Flag set to activate the sampling of the total service time + * of a just-arrived first I/O request (see + * bfq_update_inject_limit()). This will cause the setting of + * waited_rq when the request is finally dispatched. + */ + bool wait_dispatch; + /* + * If set, then bfq_update_inject_limit() is invoked when + * waited_rq is eventually completed. + */ + struct request *waited_rq; + /* + * True if some request has been injected during the last service hole. + */ + bool rqs_injected; + /* time of first rq dispatch in current observation interval (ns) */ u64 first_dispatch; /* time of last rq dispatch in current observation interval (ns) */ @@ -553,6 +562,7 @@ struct bfq_data { ktime_t last_budget_start; /* beginning of the last idle slice */ ktime_t last_idling_start; + unsigned long last_idling_start_jiffies; /* number of samples in current observation interval */ int peak_rate_samples; @@ -898,10 +908,10 @@ 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_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq); void bfq_weights_tree_add(struct bfq_data *bfqd, struct bfq_queue *bfqq, - struct rb_root *root); + struct rb_root_cached *root); void __bfq_weights_tree_remove(struct bfq_data *bfqd, struct bfq_queue *bfqq, - struct rb_root *root); + struct rb_root_cached *root); void bfq_weights_tree_remove(struct bfq_data *bfqd, struct bfq_queue *bfqq); void bfq_bfqq_expire(struct bfq_data *bfqd, struct bfq_queue *bfqq, @@ -1008,13 +1018,23 @@ void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq); /* --------------- end of interface of B-WF2Q+ ---------------- */ /* Logging facilities. */ +static inline void bfq_pid_to_str(int pid, char *str, int len) +{ + if (pid != -1) + snprintf(str, len, "%d", pid); + else + snprintf(str, len, "SHARED-"); +} + #ifdef CONFIG_BFQ_GROUP_IOSCHED struct bfq_group *bfqq_group(struct bfq_queue *bfqq); #define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do { \ + char pid_str[MAX_PID_STR_LENGTH]; \ + bfq_pid_to_str((bfqq)->pid, pid_str, MAX_PID_STR_LENGTH); \ blk_add_cgroup_trace_msg((bfqd)->queue, \ bfqg_to_blkg(bfqq_group(bfqq))->blkcg, \ - "bfq%d%c " fmt, (bfqq)->pid, \ + "bfq%s%c " fmt, pid_str, \ bfq_bfqq_sync((bfqq)) ? 'S' : 'A', ##args); \ } while (0) @@ -1025,10 +1045,13 @@ struct bfq_group *bfqq_group(struct bfq_queue *bfqq); #else /* CONFIG_BFQ_GROUP_IOSCHED */ -#define bfq_log_bfqq(bfqd, bfqq, fmt, args...) \ - blk_add_trace_msg((bfqd)->queue, "bfq%d%c " fmt, (bfqq)->pid, \ +#define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do { \ + char pid_str[MAX_PID_STR_LENGTH]; \ + bfq_pid_to_str((bfqq)->pid, pid_str, MAX_PID_STR_LENGTH); \ + blk_add_trace_msg((bfqd)->queue, "bfq%s%c " fmt, pid_str, \ bfq_bfqq_sync((bfqq)) ? 'S' : 'A', \ - ##args) + ##args); \ +} while (0) #define bfq_log_bfqg(bfqd, bfqg, fmt, args...) do {} while (0) #endif /* CONFIG_BFQ_GROUP_IOSCHED */ |