PROBE::IOBLOCK_TRACE(3stIO)Scheduler and block IO TPROBE::IOBLOCK_TRACE(3stap)NAMEprobe::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
None
DESCRIPTION
name - name of the probe point q - request queue on which this bio was
queued. devname - device for which a buffer bounce was needed. ino -
i-node number of the mapped file bytes_done - number of bytes
transferred 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 makes 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. 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 creating a block IO request.
SystemTap Tapset Reference March 2013 PROBE::IOBLOCK_TRACE(3stap)
