PROBE::IOBLOCK.REQ(3stapIO Scheduler and block IO TapPROBE::IOBLOCK.REQ(3stap)NAMEprobe::ioblock.request - Fires whenever making a generic block I/O
request.
SYNOPSIS
ioblock.request
VALUES
None
DESCRIPTION
name - name of the probe point devname - block device name ino - i-node
number of the mapped file sector - beginning sector for the entire bio
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
rw - binary trace for read/write request vcnt - bio vector count which
represents number of array element (page, offset, length) which make up
this I/O request idx - offset into the bio vector array phys_segments -
number of segments in this bio after physical address coalescing is
performed hw_segments - number of segments after physical and DMA
remapping hardware coalescing is performed size - total size in bytes
bdev - target block device bdev_contains - points to the device object
which contains the partition (when bio structure represents a
partition) p_start_sect - points to the start sector of the partition
structure of the device
CONTEXT
The process makes block I/O request
SystemTap Tapset Reference November 2013 PROBE::IOBLOCK.REQ(3stap)
