1PROBE::IOBLOCK.REQ(3stap)IO Scheduler and block IO TapsPROBE::IOBLOCK.REQ(3stap)
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6 probe::ioblock.request - Fires whenever making a generic block I/O
7 request.
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10 ioblock.request
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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 size
21 total size in bytes
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23 hw_segments
24 number of segments after physical and DMA remapping hardware
25 coalescing is performed
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27 phys_segments
28 number of segments in this bio after physical address coalescing is
29 performed
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31 idx
32 offset into the bio vector array
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34 bdev
35 target block device
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37 bdev_contains
38 points to the device object which contains the partition (when bio
39 structure represents a partition)
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41 vcnt
42 bio vector count which represents number of array element (page,
43 offset, length) which make up this I/O request
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45 opf
46 operations and flags
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48 rw
49 binary trace for read/write request
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51 ino
52 i-node number of the mapped file
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54 sector
55 beginning sector for the entire bio
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57 devname
58 block device name
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60 p_start_sect
61 points to the start sector of the partition structure of the device
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63 name
64 name of the probe point
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67 The process makes block I/O request
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70 tapset::ioblock(3stap)
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74SystemTap Tapset Reference April 2023 PROBE::IOBLOCK.REQ(3stap)