1PROBE::IOBLOCK_TRACE(3staIpO)Scheduler and block IO TaPpRsOBE::IOBLOCK_TRACE(3stap)
2
3
4
6 probe::ioblock_trace.request - Fires just as a generic block I/O
7 request is created for a bio.
8
10 ioblock_trace.request
11
13 idx
14 offset into the bio vector array phys_segments - number of segments
15 in this bio after physical address coalescing is performed.
16
17 bdev
18 target block device
19
20 rw
21 binary trace for read/write request
22
23 q
24 request queue on which this bio was queued.
25
26 bytes_done
27 number of bytes transferred
28
29 name
30 name of the probe point
31
32 ino
33 i-node number of the mapped file
34
35 bdev_contains
36 points to the device object which contains the partition (when bio
37 structure represents a partition)
38
39 size
40 total size in bytes
41
42 vcnt
43 bio vector count which represents number of array element (page,
44 offset, length) which make up this I/O request
45
46 devname
47 block device name
48
49 p_start_sect
50 points to the start sector of the partition structure of the device
51
52 sector
53 beginning sector for the entire bio
54
55 opf
56 operations and flags
57
58 flags
59 see below BIO_UPTODATE 0 ok after I/O completion BIO_RW_BLOCK 1
60 RW_AHEAD set, and read/write would block BIO_EOF 2 out-out-bounds
61 error BIO_SEG_VALID 3 nr_hw_seg valid BIO_CLONED 4 doesn't own data
62 BIO_BOUNCED 5 bio is a bounce bio BIO_USER_MAPPED 6 contains user
63 pages BIO_EOPNOTSUPP 7 not supported
64
66 The process makes block I/O request
67
69 tapset::ioblock(3stap)
70
71
72
73SystemTap Tapset Reference June 2018 PROBE::IOBLOCK_TRACE(3stap)