Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:block\bfq-iosched.c Create Date:2022-07-28 17:55:03
Last Modify:2020-03-12 14:18:49 Copyright©Brick
home page Tree
Annotation kernel can get tool activityDownload SCCTChinese

Name:bfq_add_request

Proto:static void bfq_add_request(struct request *rq)

Type:void

Parameter:

TypeParameterName
struct request *rq
1866  bfqq = RQ_BFQQ(rq)
1867  bfqd = parent bfq_data
1869  old_wr_coeff = actor by which the weight of this queue is multiplied
1870  bool interactive = false
1872  bfq_log_bfqq(bfqd, bfqq, "add_request %d", rq_is_sync(rq))
1873  umber of sync and async requests queued [rq_is_sync(rq)]++
1874  number of queued requests ++
1876  If RB_EMPTY_ROOT( & sorted list of pending requests ) && bfq_bfqq_sync(bfqq) Then
1931  If bfqq owning the last completed rq && Not bfq_bfqq_has_short_ttime(bfqq) && ktime_get_ns() - time of last request completion (ns) < 200 * NSEC_PER_USEC Then
1935  If bfqq owning the last completed rq != bfqq && bfqq owning the last completed rq != Pointer to the waker queue for this queue, i.e., to the* queue Q such that this queue happens to get new I/O right* after some I/O request of Q is completed. For details, see* the comments on the choice of the queue for injection in* bfq_select_queue(). Then
1972  Else if bfqq owning the last completed rq == Pointer to the waker queue for this queue, i.e., to the* queue Q such that this queue happens to get new I/O right* after some I/O request of Q is completed. For details, see* the comments on the choice of the queue for injection in* bfq_select_queue(). && Not bfq_bfqq_has_waker(bfqq) Then
1989  If ime_is_before_eq_jiffies(a) return true if a is before or equal to jiffies(last time the inject limit has been decreased, in jiffies + msecs_to_jiffies: - convert milliseconds to jiffies*@m: time in milliseconds* conversion is done as follows:* - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET)* - 'too large' values [that would result in larger than) Then bfq_reset_inject_limit(bfqd, bfqq)
2018  If bfqq == bfq_queue in service && ( number of requests dispatched and waiting for completion == 0 || last total-service-time sample, see bfq_update_inject_limit() > 0 && * True if some request has been injected during the last service hole. && number of requests dispatched and waiting for completion > 0 ) && ime_is_before_eq_jiffies(a) return true if a is before or equal to jiffies(last time the inject limit has been decreased, in jiffies + msecs_to_jiffies: - convert milliseconds to jiffies*@m: time in milliseconds* conversion is done as follows:* - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET)* - 'too large' values [that would result in larger than) Then
2024  time of last transition from empty to non-empty (ns) = ktime_get_ns()
2031  * 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. = true
2045  If number of requests dispatched and waiting for completion == 0 Then * True if some request has been injected during the last service hole. = false
2050  RB-tree support functions for inserting/lookup/removal of requests* in a sorted RB tree.
2055  prev = fifo isn't expired, next request to serve
2056  next_rq = Lifted from AS - choose which of rq1 and rq2 that is best served now.* We choose the request that is closer to the head right now. Distance* behind the head is penalized and only allowed to a certain extent.
2057  fifo isn't expired, next request to serve = next_rq
2063  If Value for the false possibility is greater at compile time(! true if the device is non rotational and performs queueing && prev != fifo isn't expired, next request to serve ) Then The following function is not marked as __cold because it is* actually cold, but for the same performance goal described in the* comments on the likely() at the beginning of* bfq_setup_cooperator()
2066  If Not bfq_bfqq_busy(bfqq) Then bfq_bfqq_handle_idle_busy_switch(bfqd, bfqq, old_wr_coeff, rq, & interactive)
2069  Else
2070  If if set to true, low-latency heuristics are enabled && old_wr_coeff == 1 && Not rq_is_sync(rq) && ime_is_before_jiffies(a) return true if a is before jiffies (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. + * Minimum period between request arrivals after which * weight-raising may be reactivated for an already busy async * queue (in jiffies).) Then
2074  actor by which the weight of this queue is multiplied = * Maximum factor by which the weight of a weight-raised queue * is multiplied.
2075  current maximum weight-raising time for this queue = bfq_wr_duration(bfqd)
2077  number of weight-raised busy @bfq_queues ++
2078  flag, set to request a weight, ioprio or ioprio_class change = 1
2080  If prev != fifo isn't expired, next request to serve Then q_updated_next_req - update the queue after a new next_rq selection
2110  If if set to true, low-latency heuristics are enabled && ( old_wr_coeff == 1 || actor by which the weight of this queue is multiplied == 1 || interactive) Then 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. = jiffies
Caller
NameDescribe
__bfq_insert_requestrns true if it causes the idle timer to be disabled