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 devname
21 block device name
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23 phys_segments
24 number of segments in this bio after physical address coalescing is
25 performed
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27 bdev
28 target block device
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30 sector
31 beginning sector for the entire bio
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33 name
34 name of the probe point
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36 size
37 total size in bytes
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39 p_start_sect
40 points to the start sector of the partition structure of the device
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42 vcnt
43 bio vector count which represents number of array element (page,
44 offset, length) which make up this I/O request
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46 idx
47 offset into the bio vector array
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49 hw_segments
50 number of segments after physical and DMA remapping hardware
51 coalescing is performed
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53 ino
54 i-node number of the mapped file
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56 bdev_contains
57 points to the device object which contains the partition (when bio
58 structure represents a partition)
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60 rw
61 binary trace for read/write request
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64 The process makes block I/O request
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67 tapset::ioblock(3stap)
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71SystemTap Tapset Reference June 2018 PROBE::IOBLOCK.REQ(3stap)