1PROBE::IOBLOCK_TRACE(3staIpO)Scheduler and block IO TaPpRsOBE::IOBLOCK_TRACE(3stap)
2
3
4

NAME

6       probe::ioblock_trace.bounce - Fires whenever a buffer bounce is needed
7       for at least one page of a block IO request.
8

SYNOPSIS

10       ioblock_trace.bounce
11

VALUES

13       bdev
14           target block device
15
16       name
17           name of the probe point
18
19       devname
20           device for which a buffer bounce was needed.
21
22       vcnt
23           bio vector count which represents number of array element (page,
24           offset, length) which makes up this I/O request
25
26       opf
27           operations and flags
28
29       ino
30           i-node number of the mapped file
31
32       bytes_done
33           number of bytes transferred
34
35       bdev_contains
36           points to the device object which contains the partition (when bio
37           structure represents a partition)
38
39       q
40           request queue on which this bio was queued.
41
42       flags
43           see below BIO_UPTODATE 0 ok after I/O completion BIO_RW_BLOCK 1
44           RW_AHEAD set, and read/write would block BIO_EOF 2 out-out-bounds
45           error BIO_SEG_VALID 3 nr_hw_seg valid BIO_CLONED 4 doesn't own data
46           BIO_BOUNCED 5 bio is a bounce bio BIO_USER_MAPPED 6 contains user
47           pages BIO_EOPNOTSUPP 7 not supported
48
49       size
50           total size in bytes
51
52       rw
53           binary trace for read/write request
54
55       p_start_sect
56           points to the start sector of the partition structure of the device
57
58       idx
59           offset into the bio vector array phys_segments - number of segments
60           in this bio after physical address coalescing is performed.
61
62       sector
63           beginning sector for the entire bio
64

CONTEXT

66       The process creating a block IO request.
67

SEE ALSO

69       tapset::ioblock(3stap)
70
71
72
73SystemTap Tapset Reference         May 2021        PROBE::IOBLOCK_TRACE(3stap)
Impressum