| /* |
| * BFQ-v7r8 for 3.4.0: data structures and common functions prototypes. |
| * |
| * Based on ideas and code from CFQ: |
| * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> |
| * |
| * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it> |
| * Paolo Valente <paolo.valente@unimore.it> |
| * |
| * Copyright (C) 2010 Paolo Valente <paolo.valente@unimore.it> |
| */ |
| |
| #ifndef _BFQ_H |
| #define _BFQ_H |
| |
| #include <linux/blktrace_api.h> |
| #include <linux/hrtimer.h> |
| #include <linux/ioprio.h> |
| #include <linux/rbtree.h> |
| |
| #define BFQ_IOPRIO_CLASSES 3 |
| #define BFQ_CL_IDLE_TIMEOUT (HZ/5) |
| |
| #define BFQ_MIN_WEIGHT 1 |
| #define BFQ_MAX_WEIGHT 1000 |
| |
| #define BFQ_DEFAULT_QUEUE_IOPRIO 4 |
| |
| #define BFQ_DEFAULT_GRP_WEIGHT 10 |
| #define BFQ_DEFAULT_GRP_IOPRIO 0 |
| #define BFQ_DEFAULT_GRP_CLASS IOPRIO_CLASS_BE |
| |
| struct bfq_entity; |
| |
| /** |
| * struct bfq_service_tree - per ioprio_class service tree. |
| * @active: tree for active entities (i.e., those backlogged). |
| * @idle: tree for idle entities (i.e., those not backlogged, with V <= F_i). |
| * @first_idle: idle entity with minimum F_i. |
| * @last_idle: idle entity with maximum F_i. |
| * @vtime: scheduler virtual time. |
| * @wsum: scheduler weight sum; active and idle entities contribute to it. |
| * |
| * Each service tree represents a B-WF2Q+ scheduler on its own. Each |
| * ioprio_class has its own independent scheduler, and so its own |
| * bfq_service_tree. All the fields are protected by the queue lock |
| * of the containing bfqd. |
| */ |
| struct bfq_service_tree { |
| struct rb_root active; |
| struct rb_root idle; |
| |
| struct bfq_entity *first_idle; |
| struct bfq_entity *last_idle; |
| |
| u64 vtime; |
| unsigned long wsum; |
| }; |
| |
| /** |
| * struct bfq_sched_data - multi-class scheduler. |
| * @in_service_entity: entity in service. |
| * @next_in_service: head-of-the-line entity in the scheduler. |
| * @service_tree: array of service trees, one per ioprio_class. |
| * |
| * 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. |
| * |
| * 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. |
| */ |
| struct bfq_sched_data { |
| struct bfq_entity *in_service_entity; |
| struct bfq_entity *next_in_service; |
| struct bfq_service_tree service_tree[BFQ_IOPRIO_CLASSES]; |
| }; |
| |
| /** |
| * struct bfq_weight_counter - counter of the number of all active entities |
| * with a given weight. |
| * @weight: weight of the entities that this counter refers to. |
| * @num_active: number of active entities with this weight. |
| * @weights_node: weights tree member (see bfq_data's @queue_weights_tree |
| * and @group_weights_tree). |
| */ |
| struct bfq_weight_counter { |
| short int weight; |
| unsigned int num_active; |
| struct rb_node weights_node; |
| }; |
| |
| /** |
| * struct bfq_entity - schedulable entity. |
| * @rb_node: service_tree member. |
| * @weight_counter: pointer to the weight counter associated with this entity. |
| * @on_st: flag, true if the entity is on a tree (either the active or |
| * the idle one of its service_tree). |
| * @finish: B-WF2Q+ finish timestamp (aka F_i). |
| * @start: B-WF2Q+ start timestamp (aka S_i). |
| * @tree: tree the entity is enqueued into; %NULL if not on a tree. |
| * @min_start: minimum start time of the (active) subtree rooted at |
| * this entity; used for O(log N) lookups into active trees. |
| * @service: service received during the last round of service. |
| * @budget: budget used to calculate F_i; F_i = S_i + @budget / @weight. |
| * @weight: weight of the queue |
| * @parent: parent entity, for hierarchical scheduling. |
| * @my_sched_data: for non-leaf nodes in the cgroup hierarchy, the |
| * associated scheduler queue, %NULL on leaf nodes. |
| * @sched_data: the scheduler queue this entity belongs to. |
| * @ioprio: the ioprio in use. |
| * @new_weight: when a weight change is requested, the new weight value. |
| * @orig_weight: original weight, used to implement weight boosting |
| * @new_ioprio: when an ioprio change is requested, the new ioprio value. |
| * @ioprio_class: the ioprio_class in use. |
| * @new_ioprio_class: when an ioprio_class change is requested, the new |
| * ioprio_class value. |
| * @ioprio_changed: flag, true when the user requested a weight, ioprio or |
| * ioprio_class change. |
| * |
| * A bfq_entity is used to represent either a bfq_queue (leaf node in the |
| * cgroup hierarchy) or a bfq_group into the upper level scheduler. Each |
| * entity belongs to the sched_data of the parent group in the cgroup |
| * hierarchy. Non-leaf entities have also their own sched_data, stored |
| * in @my_sched_data. |
| * |
| * Each entity stores independently its priority values; this would |
| * allow different weights on different devices, but this |
| * functionality is not exported to userspace by now. Priorities and |
| * weights are updated lazily, first storing the new values into the |
| * new_* fields, then setting the @ioprio_changed flag. As soon as |
| * there is a transition in the entity state that allows the priority |
| * update to take place the effective and the requested priority |
| * values are synchronized. |
| * |
| * 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 |
| * 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 |
| * guaranteed. All the fields are protected by the queue lock of the |
| * containing bfqd. |
| */ |
| struct bfq_entity { |
| struct rb_node rb_node; |
| struct bfq_weight_counter *weight_counter; |
| |
| int on_st; |
| |
| u64 finish; |
| u64 start; |
| |
| struct rb_root *tree; |
| |
| u64 min_start; |
| |
| unsigned long service, budget; |
| unsigned short weight, new_weight; |
| unsigned short orig_weight; |
| |
| struct bfq_entity *parent; |
| |
| struct bfq_sched_data *my_sched_data; |
| struct bfq_sched_data *sched_data; |
| |
| unsigned short ioprio, new_ioprio; |
| unsigned short ioprio_class, new_ioprio_class; |
| |
| int ioprio_changed; |
| }; |
| |
| struct bfq_group; |
| |
| /** |
| * struct bfq_queue - leaf schedulable entity. |
| * @ref: reference counter. |
| * @bfqd: parent bfq_data. |
| * @new_bfqq: shared bfq_queue if queue is cooperating with |
| * one or more other queues. |
| * @pos_node: request-position tree member (see bfq_data's @rq_pos_tree). |
| * @pos_root: request-position tree root (see bfq_data's @rq_pos_tree). |
| * @sort_list: sorted list of pending requests. |
| * @next_rq: if fifo isn't expired, next request to serve. |
| * @queued: nr of requests queued in @sort_list. |
| * @allocated: currently allocated requests. |
| * @meta_pending: pending metadata requests. |
| * @fifo: fifo list of requests in sort_list. |
| * @entity: entity representing this queue in the scheduler. |
| * @max_budget: maximum budget allowed from the feedback mechanism. |
| * @budget_timeout: budget expiration (in jiffies). |
| * @dispatched: number of requests on the dispatch list or inside driver. |
| * @flags: status flags. |
| * @bfqq_list: node for active/idle bfqq list inside our bfqd. |
| * @burst_list_node: node for the device's burst list. |
| * @seek_samples: number of seeks sampled |
| * @seek_total: sum of the distances of the seeks sampled |
| * @seek_mean: mean seek distance |
| * @last_request_pos: position of the last request enqueued |
| * @requests_within_timer: number of consecutive pairs of request completion |
| * and arrival, such that the queue becomes idle |
| * after the completion, but the next request arrives |
| * within an idle time slice; used only if the queue's |
| * IO_bound has been cleared. |
| * @pid: pid of the process owning the queue, used for logging purposes. |
| * @last_wr_start_finish: start time of the current weight-raising period if |
| * the @bfq-queue is being weight-raised, otherwise |
| * finish time of the last weight-raising period |
| * @wr_cur_max_time: current max raising time for this queue |
| * @soft_rt_next_start: minimum time instant such that, only if a new |
| * request is enqueued after this time instant in an |
| * idle @bfq_queue with no outstanding requests, then |
| * the task associated with the queue it is deemed as |
| * soft real-time (see the comments to the function |
| * bfq_bfqq_softrt_next_start()) |
| * @last_idle_bklogged: time of the last transition of the @bfq_queue from |
| * idle to backlogged |
| * @service_from_backlogged: cumulative service received from the @bfq_queue |
| * since the last transition from idle to |
| * backlogged |
| * @bic: pointer to the bfq_io_cq owning the bfq_queue, set to %NULL if the |
| * queue is shared |
| * |
| * A bfq_queue is a leaf request queue; it can be associated with an |
| * io_context or more, if it is async or shared between cooperating |
| * processes. @cgroup holds a reference to the cgroup, to be sure that it |
| * does not disappear while a bfqq still references it (mostly to avoid |
| * races between request issuing and task migration followed by cgroup |
| * destruction). |
| * All the fields are protected by the queue lock of the containing bfqd. |
| */ |
| struct bfq_queue { |
| atomic_t ref; |
| struct bfq_data *bfqd; |
| |
| /* fields for cooperating queues handling */ |
| struct bfq_queue *new_bfqq; |
| struct rb_node pos_node; |
| struct rb_root *pos_root; |
| |
| struct rb_root sort_list; |
| struct request *next_rq; |
| int queued[2]; |
| int allocated[2]; |
| int meta_pending; |
| struct list_head fifo; |
| |
| struct bfq_entity entity; |
| |
| unsigned long max_budget; |
| unsigned long budget_timeout; |
| |
| int dispatched; |
| |
| unsigned int flags; |
| |
| struct list_head bfqq_list; |
| |
| struct hlist_node burst_list_node; |
| |
| unsigned int seek_samples; |
| u64 seek_total; |
| sector_t seek_mean; |
| sector_t last_request_pos; |
| |
| unsigned int requests_within_timer; |
| |
| pid_t pid; |
| struct bfq_io_cq *bic; |
| |
| /* weight-raising fields */ |
| unsigned long wr_cur_max_time; |
| unsigned long soft_rt_next_start; |
| unsigned long last_wr_start_finish; |
| unsigned int wr_coeff; |
| unsigned long last_idle_bklogged; |
| unsigned long service_from_backlogged; |
| }; |
| |
| /** |
| * struct bfq_ttime - per process thinktime stats. |
| * @ttime_total: total process thinktime |
| * @ttime_samples: number of thinktime samples |
| * @ttime_mean: average process thinktime |
| */ |
| struct bfq_ttime { |
| unsigned long last_end_request; |
| |
| unsigned long ttime_total; |
| unsigned long ttime_samples; |
| unsigned long ttime_mean; |
| }; |
| |
| /** |
| * struct bfq_io_cq - per (request_queue, io_context) structure. |
| * @icq: associated io_cq structure |
| * @bfqq: array of two process queues, the sync and the async |
| * @ttime: associated @bfq_ttime struct |
| * @wr_time_left: snapshot of the time left before weight raising ends |
| * for the sync queue associated to this process; this |
| * snapshot is taken to remember this value while the weight |
| * raising is suspended because the queue is merged with a |
| * shared queue, and is used to set @raising_cur_max_time |
| * when the queue is split from the shared queue and its |
| * weight is raised again |
| * @saved_idle_window: same purpose as the previous field for the idle |
| * window |
| * @saved_IO_bound: same purpose as the previous two fields for the I/O |
| * bound classification of a queue |
| * @saved_in_large_burst: same purpose as the previous fields for the |
| * value of the field keeping the queue's belonging |
| * to a large burst |
| * @was_in_burst_list: true if the queue belonged to a burst list |
| * before its merge with another cooperating queue |
| * @cooperations: counter of consecutive successful queue merges underwent |
| * by any of the process' @bfq_queues |
| * @failed_cooperations: counter of consecutive failed queue merges of any |
| * of the process' @bfq_queues |
| */ |
| struct bfq_io_cq { |
| struct io_cq icq; /* must be the first member */ |
| struct bfq_queue *bfqq[2]; |
| struct bfq_ttime ttime; |
| int ioprio; |
| |
| unsigned int wr_time_left; |
| bool saved_idle_window; |
| bool saved_IO_bound; |
| |
| bool saved_in_large_burst; |
| bool was_in_burst_list; |
| |
| unsigned int cooperations; |
| unsigned int failed_cooperations; |
| }; |
| |
| enum bfq_device_speed { |
| BFQ_BFQD_FAST, |
| BFQ_BFQD_SLOW, |
| }; |
| |
| /** |
| * struct bfq_data - per device data structure. |
| * @queue: request queue for the managed device. |
| * @root_group: root bfq_group for the device. |
| * @rq_pos_tree: rbtree sorted by next_request position, used when |
| * determining if two or more queues have interleaving |
| * requests (see bfq_close_cooperator()). |
| * @active_numerous_groups: number of bfq_groups containing more than one |
| * active @bfq_entity. |
| * @queue_weights_tree: rbtree of weight counters of @bfq_queues, sorted by |
| * weight. Used to keep track of whether all @bfq_queues |
| * have the same weight. The tree contains one counter |
| * for each distinct weight associated to some active |
| * and not weight-raised @bfq_queue (see the comments to |
| * the functions bfq_weights_tree_[add|remove] for |
| * further details). |
| * @group_weights_tree: rbtree of non-queue @bfq_entity weight counters, sorted |
| * by weight. Used to keep track of whether all |
| * @bfq_groups have the same weight. The tree contains |
| * one counter for each distinct weight associated to |
| * some active @bfq_group (see the comments to the |
| * functions bfq_weights_tree_[add|remove] for further |
| * details). |
| * @busy_queues: number of bfq_queues containing requests (including the |
| * queue in service, even if it is idling). |
| * @busy_in_flight_queues: number of @bfq_queues containing pending or |
| * in-flight requests, plus the @bfq_queue in |
| * service, even if idle but waiting for the |
| * possible arrival of its next sync request. This |
| * field is updated only if the device is rotational, |
| * but used only if the device is also NCQ-capable. |
| * The reason why the field is updated also for non- |
| * NCQ-capable rotational devices is related to the |
| * fact that the value of @hw_tag may be set also |
| * later than when busy_in_flight_queues may need to |
| * be incremented for the first time(s). Taking also |
| * this possibility into account, to avoid unbalanced |
| * increments/decrements, would imply more overhead |
| * than just updating busy_in_flight_queues |
| * regardless of the value of @hw_tag. |
| * @const_seeky_busy_in_flight_queues: number of constantly-seeky @bfq_queues |
| * (that is, seeky queues that expired |
| * for budget timeout at least once) |
| * containing pending or in-flight |
| * requests, including the in-service |
| * @bfq_queue if constantly seeky. This |
| * field is updated only if the device |
| * is rotational, but used only if the |
| * device is also NCQ-capable (see the |
| * comments to @busy_in_flight_queues). |
| * @wr_busy_queues: number of weight-raised busy @bfq_queues. |
| * @queued: number of queued requests. |
| * @rq_in_driver: number of requests dispatched and waiting for completion. |
| * @sync_flight: number of sync requests in the driver. |
| * @max_rq_in_driver: max number of reqs in driver in the last |
| * @hw_tag_samples completed requests. |
| * @hw_tag_samples: nr of samples used to calculate hw_tag. |
| * @hw_tag: flag set to one if the driver is showing a queueing behavior. |
| * @budgets_assigned: number of budgets assigned. |
| * @idle_slice_timer: timer set when idling for the next sequential request |
| * from the queue in service. |
| * @unplug_work: delayed work to restart dispatching on the request queue. |
| * @in_service_queue: bfq_queue in service. |
| * @in_service_bic: bfq_io_cq (bic) associated with the @in_service_queue. |
| * @last_position: on-disk position of the last served request. |
| * @last_budget_start: beginning of the last budget. |
| * @last_idling_start: beginning of the last idle slice. |
| * @peak_rate: peak transfer rate observed for a budget. |
| * @peak_rate_samples: number of samples used to calculate @peak_rate. |
| * @bfq_max_budget: maximum budget allotted to a bfq_queue before |
| * rescheduling. |
| * @group_list: list of all the bfq_groups active on the device. |
| * @active_list: list of all the bfq_queues active on the device. |
| * @idle_list: list of all the bfq_queues idle on the device. |
| * @bfq_fifo_expire: timeout for async/sync requests; when it expires |
| * requests are served in fifo order. |
| * @bfq_back_penalty: weight of backward seeks wrt forward ones. |
| * @bfq_back_max: maximum allowed backward seek. |
| * @bfq_slice_idle: maximum idling time. |
| * @bfq_user_max_budget: user-configured max budget value |
| * (0 for auto-tuning). |
| * @bfq_max_budget_async_rq: maximum budget (in nr of requests) allotted to |
| * async queues. |
| * @bfq_timeout: timeout for bfq_queues to consume their budget; used to |
| * to prevent seeky queues to impose long latencies to well |
| * behaved ones (this also implies that seeky queues cannot |
| * receive guarantees in the service domain; after a timeout |
| * they are charged for the whole allocated budget, to try |
| * to preserve a behavior reasonably fair among them, but |
| * without service-domain guarantees). |
| * @bfq_coop_thresh: number of queue merges after which a @bfq_queue is |
| * no more granted any weight-raising. |
| * @bfq_failed_cooperations: number of consecutive failed cooperation |
| * chances after which weight-raising is restored |
| * to a queue subject to more than bfq_coop_thresh |
| * queue merges. |
| * @bfq_requests_within_timer: number of consecutive requests that must be |
| * issued within the idle time slice to set |
| * again idling to a queue which was marked as |
| * non-I/O-bound (see the definition of the |
| * IO_bound flag for further details). |
| * @last_ins_in_burst: last time at which a queue entered the current |
| * burst of queues being activated shortly after |
| * each other; for more details about this and the |
| * following parameters related to a burst of |
| * activations, see the comments to the function |
| * @bfq_handle_burst. |
| * @bfq_burst_interval: reference time interval used to decide whether a |
| * queue has been activated shortly after |
| * @last_ins_in_burst. |
| * @burst_size: number of queues in the current burst of queue activations. |
| * @bfq_large_burst_thresh: maximum burst size above which the current |
| * queue-activation burst is deemed as 'large'. |
| * @large_burst: true if a large queue-activation burst is in progress. |
| * @burst_list: head of the burst list (as for the above fields, more details |
| * in the comments to the function bfq_handle_burst). |
| * @low_latency: if set to true, low-latency heuristics are enabled. |
| * @bfq_wr_coeff: maximum factor by which the weight of a weight-raised |
| * queue is multiplied. |
| * @bfq_wr_max_time: maximum duration of a weight-raising period (jiffies). |
| * @bfq_wr_rt_max_time: maximum duration for soft real-time processes. |
| * @bfq_wr_min_idle_time: minimum idle period after which weight-raising |
| * may be reactivated for a queue (in jiffies). |
| * @bfq_wr_min_inter_arr_async: minimum period between request arrivals |
| * after which weight-raising may be |
| * reactivated for an already busy queue |
| * (in jiffies). |
| * @bfq_wr_max_softrt_rate: max service-rate for a soft real-time queue, |
| * sectors per seconds. |
| * @RT_prod: cached value of the product R*T used for computing the maximum |
| * duration of the weight raising automatically. |
| * @device_speed: device-speed class for the low-latency heuristic. |
| * @oom_bfqq: fallback dummy bfqq for extreme OOM conditions. |
| * |
| * All the fields are protected by the @queue lock. |
| */ |
| struct bfq_data { |
| struct request_queue *queue; |
| |
| struct bfq_group *root_group; |
| struct rb_root rq_pos_tree; |
| |
| #ifdef CONFIG_CGROUP_BFQIO |
| int active_numerous_groups; |
| #endif |
| |
| struct rb_root queue_weights_tree; |
| struct rb_root group_weights_tree; |
| |
| int busy_queues; |
| int busy_in_flight_queues; |
| int const_seeky_busy_in_flight_queues; |
| int wr_busy_queues; |
| int queued; |
| int rq_in_driver; |
| int sync_flight; |
| |
| int max_rq_in_driver; |
| int hw_tag_samples; |
| int hw_tag; |
| |
| int budgets_assigned; |
| |
| struct timer_list idle_slice_timer; |
| struct work_struct unplug_work; |
| |
| struct bfq_queue *in_service_queue; |
| struct bfq_io_cq *in_service_bic; |
| |
| sector_t last_position; |
| |
| ktime_t last_budget_start; |
| ktime_t last_idling_start; |
| int peak_rate_samples; |
| u64 peak_rate; |
| unsigned long bfq_max_budget; |
| |
| struct hlist_head group_list; |
| struct list_head active_list; |
| struct list_head idle_list; |
| |
| unsigned int bfq_fifo_expire[2]; |
| unsigned int bfq_back_penalty; |
| unsigned int bfq_back_max; |
| unsigned int bfq_slice_idle; |
| u64 bfq_class_idle_last_service; |
| |
| unsigned int bfq_user_max_budget; |
| unsigned int bfq_max_budget_async_rq; |
| unsigned int bfq_timeout[2]; |
| |
| unsigned int bfq_coop_thresh; |
| unsigned int bfq_failed_cooperations; |
| unsigned int bfq_requests_within_timer; |
| |
| unsigned long last_ins_in_burst; |
| unsigned long bfq_burst_interval; |
| int burst_size; |
| unsigned long bfq_large_burst_thresh; |
| bool large_burst; |
| struct hlist_head burst_list; |
| |
| bool low_latency; |
| |
| /* parameters of the low_latency heuristics */ |
| unsigned int bfq_wr_coeff; |
| unsigned int bfq_wr_max_time; |
| unsigned int bfq_wr_rt_max_time; |
| unsigned int bfq_wr_min_idle_time; |
| unsigned long bfq_wr_min_inter_arr_async; |
| unsigned int bfq_wr_max_softrt_rate; |
| u64 RT_prod; |
| enum bfq_device_speed device_speed; |
| |
| struct bfq_queue oom_bfqq; |
| }; |
| |
| enum bfqq_state_flags { |
| BFQ_BFQQ_FLAG_busy = 0, /* has requests or is in service */ |
| BFQ_BFQQ_FLAG_wait_request, /* waiting for a request */ |
| BFQ_BFQQ_FLAG_must_alloc, /* must be allowed rq alloc */ |
| BFQ_BFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */ |
| BFQ_BFQQ_FLAG_idle_window, /* slice idling enabled */ |
| BFQ_BFQQ_FLAG_sync, /* synchronous queue */ |
| BFQ_BFQQ_FLAG_budget_new, /* no completion with this budget */ |
| BFQ_BFQQ_FLAG_IO_bound, /* |
| * bfqq has timed-out at least once |
| * having consumed at most 2/10 of |
| * its budget |
| */ |
| BFQ_BFQQ_FLAG_in_large_burst, /* |
| * bfqq activated in a large burst, |
| * see comments to bfq_handle_burst. |
| */ |
| BFQ_BFQQ_FLAG_constantly_seeky, /* |
| * bfqq has proved to be slow and |
| * seeky until budget timeout |
| */ |
| BFQ_BFQQ_FLAG_softrt_update, /* |
| * may need softrt-next-start |
| * update |
| */ |
| BFQ_BFQQ_FLAG_coop, /* bfqq is shared */ |
| BFQ_BFQQ_FLAG_split_coop, /* shared bfqq will be split */ |
| BFQ_BFQQ_FLAG_just_split, /* queue has just been split */ |
| }; |
| |
| #define BFQ_BFQQ_FNS(name) \ |
| static inline void bfq_mark_bfqq_##name(struct bfq_queue *bfqq) \ |
| { \ |
| (bfqq)->flags |= (1 << BFQ_BFQQ_FLAG_##name); \ |
| } \ |
| static inline void bfq_clear_bfqq_##name(struct bfq_queue *bfqq) \ |
| { \ |
| (bfqq)->flags &= ~(1 << BFQ_BFQQ_FLAG_##name); \ |
| } \ |
| static inline int bfq_bfqq_##name(const struct bfq_queue *bfqq) \ |
| { \ |
| return ((bfqq)->flags & (1 << BFQ_BFQQ_FLAG_##name)) != 0; \ |
| } |
| |
| BFQ_BFQQ_FNS(busy); |
| BFQ_BFQQ_FNS(wait_request); |
| BFQ_BFQQ_FNS(must_alloc); |
| BFQ_BFQQ_FNS(fifo_expire); |
| BFQ_BFQQ_FNS(idle_window); |
| BFQ_BFQQ_FNS(sync); |
| BFQ_BFQQ_FNS(budget_new); |
| BFQ_BFQQ_FNS(IO_bound); |
| BFQ_BFQQ_FNS(in_large_burst); |
| BFQ_BFQQ_FNS(constantly_seeky); |
| BFQ_BFQQ_FNS(coop); |
| BFQ_BFQQ_FNS(split_coop); |
| BFQ_BFQQ_FNS(just_split); |
| BFQ_BFQQ_FNS(softrt_update); |
| #undef BFQ_BFQQ_FNS |
| |
| /* Logging facilities. */ |
| #define bfq_log_bfqq(bfqd, bfqq, fmt, args...) \ |
| blk_add_trace_msg((bfqd)->queue, "bfq%d " fmt, (bfqq)->pid, ##args) |
| |
| #define bfq_log(bfqd, fmt, args...) \ |
| blk_add_trace_msg((bfqd)->queue, "bfq " fmt, ##args) |
| |
| /* Expiration reasons. */ |
| enum bfqq_expiration { |
| BFQ_BFQQ_TOO_IDLE = 0, /* |
| * queue has been idling for |
| * too long |
| */ |
| BFQ_BFQQ_BUDGET_TIMEOUT, /* budget took too long to be used */ |
| BFQ_BFQQ_BUDGET_EXHAUSTED, /* budget consumed */ |
| BFQ_BFQQ_NO_MORE_REQUESTS, /* the queue has no more requests */ |
| }; |
| |
| #ifdef CONFIG_CGROUP_BFQIO |
| /** |
| * struct bfq_group - per (device, cgroup) data structure. |
| * @entity: schedulable entity to insert into the parent group sched_data. |
| * @sched_data: own sched_data, to contain child entities (they may be |
| * both bfq_queues and bfq_groups). |
| * @group_node: node to be inserted into the bfqio_cgroup->group_data |
| * list of the containing cgroup's bfqio_cgroup. |
| * @bfqd_node: node to be inserted into the @bfqd->group_list list |
| * of the groups active on the same device; used for cleanup. |
| * @bfqd: the bfq_data for the device this group acts upon. |
| * @async_bfqq: array of async queues for all the tasks belonging to |
| * the group, one queue per ioprio value per ioprio_class, |
| * except for the idle class that has only one queue. |
| * @async_idle_bfqq: async queue for the idle class (ioprio is ignored). |
| * @my_entity: pointer to @entity, %NULL for the toplevel group; used |
| * to avoid too many special cases during group creation/ |
| * migration. |
| * @active_entities: number of active entities belonging to the group; |
| * unused for the root group. Used to know whether there |
| * are groups with more than one active @bfq_entity |
| * (see the comments to the function |
| * bfq_bfqq_must_not_expire()). |
| * |
| * Each (device, cgroup) pair has its own bfq_group, i.e., for each cgroup |
| * there is a set of bfq_groups, each one collecting the lower-level |
| * entities belonging to the group that are acting on the same device. |
| * |
| * Locking works as follows: |
| * o @group_node is protected by the bfqio_cgroup lock, and is accessed |
| * via RCU from its readers. |
| * o @bfqd is protected by the queue lock, RCU is used to access it |
| * from the readers. |
| * o All the other fields are protected by the @bfqd queue lock. |
| */ |
| struct bfq_group { |
| struct bfq_entity entity; |
| struct bfq_sched_data sched_data; |
| |
| struct hlist_node group_node; |
| struct hlist_node bfqd_node; |
| |
| void *bfqd; |
| |
| struct bfq_queue *async_bfqq[2][IOPRIO_BE_NR]; |
| struct bfq_queue *async_idle_bfqq; |
| |
| struct bfq_entity *my_entity; |
| |
| int active_entities; |
| }; |
| |
| /** |
| * struct bfqio_cgroup - bfq cgroup data structure. |
| * @css: subsystem state for bfq in the containing cgroup. |
| * @weight: cgroup weight. |
| * @ioprio: cgroup ioprio. |
| * @ioprio_class: cgroup ioprio_class. |
| * @lock: spinlock that protects @ioprio, @ioprio_class and @group_data. |
| * @group_data: list containing the bfq_group belonging to this cgroup. |
| * |
| * @group_data is accessed using RCU, with @lock protecting the updates, |
| * @ioprio and @ioprio_class are protected by @lock. |
| */ |
| struct bfqio_cgroup { |
| struct cgroup_subsys_state css; |
| |
| unsigned short weight, ioprio, ioprio_class; |
| |
| spinlock_t lock; |
| struct hlist_head group_data; |
| }; |
| #else |
| struct bfq_group { |
| struct bfq_sched_data sched_data; |
| |
| struct bfq_queue *async_bfqq[2][IOPRIO_BE_NR]; |
| struct bfq_queue *async_idle_bfqq; |
| }; |
| #endif |
| |
| static inline struct bfq_service_tree * |
| bfq_entity_service_tree(struct bfq_entity *entity) |
| { |
| struct bfq_sched_data *sched_data = entity->sched_data; |
| unsigned int idx = entity->ioprio_class - 1; |
| |
| BUG_ON(idx >= BFQ_IOPRIO_CLASSES); |
| BUG_ON(sched_data == NULL); |
| |
| return sched_data->service_tree + idx; |
| } |
| |
| static inline struct bfq_queue *bic_to_bfqq(struct bfq_io_cq *bic, |
| bool is_sync) |
| { |
| return bic->bfqq[is_sync]; |
| } |
| |
| static inline void bic_set_bfqq(struct bfq_io_cq *bic, |
| struct bfq_queue *bfqq, bool is_sync) |
| { |
| bic->bfqq[is_sync] = bfqq; |
| } |
| |
| static inline struct bfq_data *bic_to_bfqd(struct bfq_io_cq *bic) |
| { |
| return bic->icq.q->elevator->elevator_data; |
| } |
| |
| /** |
| * bfq_get_bfqd_locked - get a lock to a bfqd using a RCU protected pointer. |
| * @ptr: a pointer to a bfqd. |
| * @flags: storage for the flags to be saved. |
| * |
| * This function allows bfqg->bfqd to be protected by the |
| * queue lock of the bfqd they reference; the pointer is dereferenced |
| * under RCU, so the storage for bfqd is assured to be safe as long |
| * as the RCU read side critical section does not end. After the |
| * bfqd->queue->queue_lock is taken the pointer is rechecked, to be |
| * sure that no other writer accessed it. If we raced with a writer, |
| * the function returns NULL, with the queue unlocked, otherwise it |
| * returns the dereferenced pointer, with the queue locked. |
| */ |
| static inline struct bfq_data *bfq_get_bfqd_locked(void **ptr, |
| unsigned long *flags) |
| { |
| struct bfq_data *bfqd; |
| |
| rcu_read_lock(); |
| bfqd = rcu_dereference(*(struct bfq_data **)ptr); |
| |
| if (bfqd != NULL) { |
| spin_lock_irqsave(bfqd->queue->queue_lock, *flags); |
| if (*ptr == bfqd) |
| goto out; |
| spin_unlock_irqrestore(bfqd->queue->queue_lock, *flags); |
| } |
| |
| bfqd = NULL; |
| out: |
| rcu_read_unlock(); |
| return bfqd; |
| } |
| |
| static inline void bfq_put_bfqd_unlock(struct bfq_data *bfqd, |
| unsigned long *flags) |
| { |
| spin_unlock_irqrestore(bfqd->queue->queue_lock, *flags); |
| } |
| |
| static void bfq_check_ioprio_change(struct io_context *ioc, |
| struct bfq_io_cq *bic); |
| static void bfq_put_queue(struct bfq_queue *bfqq); |
| static void bfq_dispatch_insert(struct request_queue *q, struct request *rq); |
| static struct bfq_queue *bfq_get_queue(struct bfq_data *bfqd, |
| struct bfq_group *bfqg, int is_sync, |
| struct io_context *ioc, gfp_t gfp_mask); |
| static void bfq_end_wr_async_queues(struct bfq_data *bfqd, |
| struct bfq_group *bfqg); |
| static void bfq_put_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg); |
| static void bfq_exit_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq); |
| |
| #endif /* _BFQ_H */ |