Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:block\bfq-iosched.c Create Date:2022-07-28 17:55:53
Last Modify:2020-03-12 14:18:49 Copyright©Brick
home page Tree
Annotation kernel can get tool activityDownload SCCTChinese

Name:In autotuning mode, max_budget is dynamically recomputed as the* amount of sectors transferred in timeout at the estimated peak* rate. This enables BFQ to utilize a full timeslice with a full* budget, even if the in-service queue is served at peak rate

Proto:static unsigned long bfq_calc_max_budget(struct bfq_data *bfqd)

Type:unsigned long

Parameter:

TypeParameterName
struct bfq_data *bfqd
3001  Return * Current estimate of the device peak rate, measured in * [(sectors/usec) / 2^BFQ_RATE_SHIFT]. The left-shift by * BFQ_RATE_SHIFT is performed to increase precision in * fixed-point calculations. * USEC_PER_MSEC * Convert jiffies to milliseconds and back.* Avoid unnecessary multiplications/divisions in the* two most common HZ cases: >> Shift used for peak-rate fixed precision calculations
Caller
NameDescribe
update_thr_responsiveness_paramsUpdate parameters related to throughput and responsiveness, as a* function of the estimated peak rate. See comments on* bfq_calc_max_budget(), and on the ref_wr_duration array.
bfq_max_budget_store
bfq_timeout_sync_storeLeaving this name to preserve name compatibility with cfq* parameters, but this timeout is used for both sync and async.