1BLK_QUEUE_MERGE_BVEC(9)          Block Devices         BLK_QUEUE_MERGE_BVEC(9)
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NAME

6       blk_queue_merge_bvec - set a merge_bvec function for queue
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SYNOPSIS

9       void blk_queue_merge_bvec(struct request_queue * q,
10                                 merge_bvec_fn * mbfn);
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ARGUMENTS

13       q
14           queue
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16       mbfn
17           merge_bvec_fn
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DESCRIPTION

20       Usually queues have static limitations on the max sectors or segments
21       that we can put in a request. Stacking drivers may have some settings
22       that are dynamic, and thus we have to query the queue whether it is ok
23       to add a new bio_vec to a bio at a given offset or not. If the block
24       device has such limitations, it needs to register a merge_bvec_fn to
25       control the size of bio's sent to it. Note that a block device *must*
26       allow a single page to be added to an empty bio. The block device
27       driver may want to use the bio_split function to deal with these bio's.
28       By default no merge_bvec_fn is defined for a queue, and only the fixed
29       limits are honored.
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32Kernel Hackers Manual 3.10         June 2019           BLK_QUEUE_MERGE_BVEC(9)
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