1PROBE::IOBLOCK_TRACE(3staIpO)Scheduler and block IO TaPpRsOBE::IOBLOCK_TRACE(3stap)
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6 probe::ioblock_trace.request - Fires just as a generic block I/O
7 request is created for a bio.
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10 ioblock_trace.request
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13 bdev
14 target block device
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16 vcnt
17 bio vector count which represents number of array element (page,
18 offset, length) which make up this I/O request
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20 p_start_sect
21 points to the start sector of the partition structure of the device
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23 devname
24 block device name
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26 flags
27 see below BIO_UPTODATE 0 ok after I/O completion BIO_RW_BLOCK 1
28 RW_AHEAD set, and read/write would block BIO_EOF 2 out-out-bounds
29 error BIO_SEG_VALID 3 nr_hw_seg valid BIO_CLONED 4 doesn't own data
30 BIO_BOUNCED 5 bio is a bounce bio BIO_USER_MAPPED 6 contains user
31 pages BIO_EOPNOTSUPP 7 not supported
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33 bytes_done
34 number of bytes transferred
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36 opf
37 operations and flags
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39 q
40 request queue on which this bio was queued.
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42 ino
43 i-node number of the mapped file
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45 size
46 total size in bytes
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48 rw
49 binary trace for read/write request
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51 bdev_contains
52 points to the device object which contains the partition (when bio
53 structure represents a partition)
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55 name
56 name of the probe point
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58 idx
59 offset into the bio vector array phys_segments - number of segments
60 in this bio after physical address coalescing is performed.
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62 sector
63 beginning sector for the entire bio
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66 The process makes block I/O request
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69 tapset::ioblock(3stap)
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73SystemTap Tapset Reference November 2020 PROBE::IOBLOCK_TRACE(3stap)