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       name
17           name of the probe point
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19       hw_segments
20           number of segments after physical and DMA remapping hardware
21           coalescing is performed
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23       bdev_contains
24           points to the device object which contains the partition (when bio
25           structure represents a partition)
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27       rw
28           binary trace for read/write request
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30       vcnt
31           bio vector count which represents number of array element (page,
32           offset, length) which make up this I/O request
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34       p_start_sect
35           points to the start sector of the partition structure of the device
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37       flags
38           see below BIO_UPTODATE 0 ok after I/O completion BIO_RW_BLOCK 1
39           RW_AHEAD set, and read/write would block BIO_EOF 2 out-out-bounds
40           error BIO_SEG_VALID 3 nr_hw_seg valid BIO_CLONED 4 doesn't own data
41           BIO_BOUNCED 5 bio is a bounce bio BIO_USER_MAPPED 6 contains user
42           pages BIO_EOPNOTSUPP 7 not supported
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44       devname
45           block device name
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47       idx
48           offset into the bio vector array
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50       ino
51           i-node number of the mapped file
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53       size
54           total size in bytes
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56       phys_segments
57           number of segments in this bio after physical address coalescing is
58           performed
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60       sector
61           beginning sector for the entire bio
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63       bdev
64           target block device
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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 2022          PROBE::IOBLOCK.REQ(3stap)
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