1BLK_LLD_BUSY(9)                  Block Devices                 BLK_LLD_BUSY(9)
2
3
4

NAME

6       blk_lld_busy - Check if underlying low-level drivers of a device are
7       busy
8

SYNOPSIS

10       int blk_lld_busy(struct request_queue * q);
11

ARGUMENTS

13       q
14           the queue of the device being checked
15

DESCRIPTION

17       Check if underlying low-level drivers of a device are busy. If the
18       drivers want to export their busy state, they must set own exporting
19       function using blk_queue_lld_busy first.
20
21       Basically, this function is used only by request stacking drivers to
22       stop dispatching requests to underlying devices when underlying devices
23       are busy. This behavior helps more I/O merging on the queue of the
24       request stacking driver and prevents I/O throughput regression on burst
25       I/O load.
26

RETURN

28       0 - Not busy (The request stacking driver should dispatch request) 1 -
29       Busy (The request stacking driver should stop dispatching request)
30

32Kernel Hackers Manual 3.10         June 2019                   BLK_LLD_BUSY(9)
Impressum