1PROBE::IOBLOCK_TRACE(3staIpO)Scheduler and block IO TaPpRsOBE::IOBLOCK_TRACE(3stap)
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6 probe::ioblock_trace.bounce - Fires whenever a buffer bounce is needed
7 for at least one page of a block IO request.
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10 ioblock_trace.bounce
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13 bdev
14 target block device
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16 name
17 name of the probe point
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19 devname
20 device for which a buffer bounce was needed.
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22 vcnt
23 bio vector count which represents number of array element (page,
24 offset, length) which makes up this I/O request
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26 opf
27 operations and flags
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29 ino
30 i-node number of the mapped file
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32 bytes_done
33 number of bytes transferred
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35 bdev_contains
36 points to the device object which contains the partition (when bio
37 structure represents a partition)
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39 q
40 request queue on which this bio was queued.
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42 flags
43 see below BIO_UPTODATE 0 ok after I/O completion BIO_RW_BLOCK 1
44 RW_AHEAD set, and read/write would block BIO_EOF 2 out-out-bounds
45 error BIO_SEG_VALID 3 nr_hw_seg valid BIO_CLONED 4 doesn't own data
46 BIO_BOUNCED 5 bio is a bounce bio BIO_USER_MAPPED 6 contains user
47 pages BIO_EOPNOTSUPP 7 not supported
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49 size
50 total size in bytes
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52 rw
53 binary trace for read/write request
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55 p_start_sect
56 points to the start sector of the partition structure of the device
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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 creating a block IO request.
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69 tapset::ioblock(3stap)
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73SystemTap Tapset Reference May 2021 PROBE::IOBLOCK_TRACE(3stap)