1BLK_LLD_BUSY(9)                  Block Devices                 BLK_LLD_BUSY(9)
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NAME

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

10       int blk_lld_busy(struct request_queue * q);
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ARGUMENTS

13       q
14           the queue of the device being checked
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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.
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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.
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RETURN

28       0 - Not busy (The request stacking driver should dispatch request) 1 -
29       Busy (The request stacking driver should stop dispatching request)
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32Kernel Hackers Manual 2.6.       November 2011                 BLK_LLD_BUSY(9)
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