| 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¶
hw_segments
number of segments after physical and DMA remapping
hardware coalescing is performed
opf
operations and flags
idx
offset into the bio vector array
rw
binary trace for read/write request
p_start_sect
points to the start sector of the partition structure of
the device
bdev
target block device
size
total size in bytes
phys_segments
number of segments in this bio after physical address
coalescing is performed
devname
block device name
vcnt
bio vector count which represents number of array element
(page, offset, length) which make up this I/O request
ino
i-node number of the mapped file
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
name
name of the probe point
bdev_contains
points to the device object which contains the partition
(when bio structure represents a partition)
sector
beginning sector for the entire bio
CONTEXT¶
The process makes block I/O request
SEE ALSO0¶
tapset::ioblock(3stap)
| October 2018 | SystemTap Tapset Reference |