| PROBE::IOBLOCK.REQ(3stap) | IO Scheduler and block IO Taps | PROBE::IOBLOCK.REQ(3stap) |
NAME¶
probe::ioblock.request - Fires whenever making a generic block I/O request.
SYNOPSIS¶
ioblock.request
VALUES¶
devname
block device name
bdev_contains
points to the device object which contains the partition
(when bio structure represents a partition)
name
name of the probe point
size
total size in bytes
opf
operations and flags
vcnt
bio vector count which represents number of array element
(page, offset, length) which make up this I/O request
flags
see below BIO_UPTODATE 0 ok after I/O completion
BIO_RW_BLOCK 1 RW_AHEAD set, and read/write would block BIO_EOF 2
out-out-bounds error BIO_SEG_VALID 3 nr_hw_seg valid BIO_CLONED 4 doesn't own
data BIO_BOUNCED 5 bio is a bounce bio BIO_USER_MAPPED 6 contains user pages
BIO_EOPNOTSUPP 7 not supported
sector
beginning sector for the entire bio
phys_segments
number of segments in this bio after physical address
coalescing is performed
idx
offset into the bio vector array
bdev
target block device
p_start_sect
points to the start sector of the partition structure of
the device
ino
i-node number of the mapped file
rw
binary trace for read/write request
hw_segments
number of segments after physical and DMA remapping
hardware coalescing is performed
CONTEXT¶
The process makes block I/O request
SEE ALSO0¶
tapset::ioblock(3stap)
| November 2023 | SystemTap Tapset Reference |