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

64       The process makes block I/O request
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SEE ALSO

67       tapset::ioblock(3stap)
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71SystemTap Tapset Reference         June 2018         PROBE::IOBLOCK.REQ(3stap)
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