Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:block\blk-iolatency.c Create Date:2022-07-28 17:45:17
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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Name:Change the queue depth of the iolatency_grp. We add/subtract 1/16th of the* queue depth at a time so we don't get wild swings and hopefully dial in to* fairer distribution of the overall queue depth.

Proto:static void scale_change(struct iolatency_grp *iolat, bool up)

Type:void

Parameter:

TypeParameterName
struct iolatency_grp *iolat
boolup
367  qd = Max # of requests
368  scale = scale_amount(qd, up)
369  old = max_depth
371  If old > qd Then old = qd
374  If up Then
375  If old == 1 && blkcg_unuse_delay(lat_to_blkg(iolat)) Then Return
378  If old < qd Then
379  old += scale
381  max_depth = old
382  wake_up_all( & wait)
384  Else
385  old >>= 1
386  max_depth = max - return maximum of two values of the same or compatible types*@x: first value*@y: second value(old, 1UL)
Caller
NameDescribe
check_scale_changeCheck our parent and see if the scale cookie has changed.