probe::ioblock_trace.bounce

probe::ioblock_trace.bounce
Prev	Chapter 9. IO Scheduler and block IO Tapset	Next

Name

probe::ioblock_trace.bounce — Fires whenever a buffer bounce is needed for at least one page of a block IO request.

ioblock_trace.bounce

rw: binary trace for read/write request
bdev_contains: points to the device object which contains the partition (when bio structure represents a partition)
q: request queue on which this bio was queued.
ino: i-node number of the mapped file
devname: device for which a buffer bounce was needed.
sector: beginning sector for the entire bio
bytes_done: number of bytes transferred
p_start_sect: points to the start sector of the partition structure of the device
size: total size in bytes
bdev: target block device
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
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
vcnt: bio vector count which represents number of array element (page, offset, length) which makes up this I/O request
opf: operations and flags

The process creating a block IO request.

Prev	Up	Next
probe::ioblock.request	Home	probe::ioblock_trace.end