1PROBE::IOBLOCK_TRACE(3staIpO)Scheduler and block IO TaPpRsOBE::IOBLOCK_TRACE(3stap)
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NAME

6       probe::ioblock_trace.request - Fires just as a generic block I/O
7       request is created for a bio.
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SYNOPSIS

10       ioblock_trace.request
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VALUES

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

66       The process makes block I/O request
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SEE ALSO

69       tapset::ioblock(3stap)
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73SystemTap Tapset Reference       November 2019     PROBE::IOBLOCK_TRACE(3stap)
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