1PROBE::IOBLOCK.REQ(3stap)IO Scheduler and block IO TapsPROBE::IOBLOCK.REQ(3stap)
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NAME

6       probe::ioblock.request - Fires whenever making a generic block I/O
7       request.
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SYNOPSIS

10       ioblock.request
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VALUES

13       opf
14           operations and flags
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16       p_start_sect
17           points to the start sector of the partition structure of the device
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19       size
20           total size in bytes
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22       vcnt
23           bio vector count which represents number of array element (page,
24           offset, length) which make up this I/O request
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26       bdev
27           target block device
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29       idx
30           offset into the bio vector array
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32       phys_segments
33           number of segments in this bio after physical address coalescing is
34           performed
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36       bdev_contains
37           points to the device object which contains the partition (when bio
38           structure represents a partition)
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40       devname
41           block device name
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43       hw_segments
44           number of segments after physical and DMA remapping hardware
45           coalescing is performed
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47       flags
48           see below BIO_UPTODATE 0 ok after I/O completion BIO_RW_BLOCK 1
49           RW_AHEAD set, and read/write would block BIO_EOF 2 out-out-bounds
50           error BIO_SEG_VALID 3 nr_hw_seg valid BIO_CLONED 4 doesn't own data
51           BIO_BOUNCED 5 bio is a bounce bio BIO_USER_MAPPED 6 contains user
52           pages BIO_EOPNOTSUPP 7 not supported
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54       name
55           name of the probe point
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57       sector
58           beginning sector for the entire bio
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60       ino
61           i-node number of the mapped file
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63       rw
64           binary trace for read/write request
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CONTEXT

67       The process makes block I/O request
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SEE ALSO

70       tapset::ioblock(3stap)
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74SystemTap Tapset Reference         May 2019          PROBE::IOBLOCK.REQ(3stap)
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