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 rw
14 binary trace for read/write request
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16 bdev_contains
17 points to the device object which contains the partition (when bio
18 structure represents a partition)
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20 ino
21 i-node number of the mapped file
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23 sector
24 beginning sector for the entire bio
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26 p_start_sect
27 points to the start sector of the partition structure of the device
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29 size
30 total size in bytes
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32 vcnt
33 bio vector count which represents number of array element (page,
34 offset, length) which make up this I/O request
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36 phys_segments
37 number of segments in this bio after physical address coalescing is
38 performed
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40 opf
41 operations and flags
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43 idx
44 offset into the bio vector array
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46 devname
47 block device name
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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 name
57 name of the probe point
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59 bdev
60 target block device
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62 hw_segments
63 number of segments after physical and DMA remapping hardware
64 coalescing is performed
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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 November 2021 PROBE::IOBLOCK.REQ(3stap)