PROBE::IOBLOCK_TRACE
Section: IO Scheduler and block IO Taps (3stap)
Updated: November 2020
Page Index
NAME
probe::ioblock_trace.bounce - Fires whenever a buffer bounce is needed for at least one page of a block IO request.
SYNOPSIS
ioblock_trace.bounce
VALUES
bdev_contains
-
points to the device object which contains the partition (when bio structure represents a partition)
size
-
total size in bytes
ino
-
i-node number of the mapped file
rw
-
binary trace for read/write request
sector
-
beginning sector for the entire bio
idx
-
offset into the bio vector array
phys_segments
- number of segments in this bio after physical address coalescing is performed.
name
-
name of the probe point
bdev
-
target block device
vcnt
-
bio vector count which represents number of array element (page, offset, length) which makes up this I/O request
q
-
request queue on which this bio was queued.
bytes_done
-
number of bytes transferred
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
p_start_sect
-
points to the start sector of the partition structure of the device
devname
-
device for which a buffer bounce was needed.
opf
-
operations and flags
CONTEXT
The process creating a block IO request.
SEE ALSO
tapset::ioblock(3stap)