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

6       probe::ioblock_trace.bounce - Fires whenever a buffer bounce is needed
7       for at least one page of a block IO request.
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SYNOPSIS

10       ioblock_trace.bounce
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VALUES

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

66       The process creating a block IO request.
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SEE ALSO

69       tapset::ioblock(3stap)
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73SystemTap Tapset Reference       November 2020     PROBE::IOBLOCK_TRACE(3stap)
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