Probes
The io probes are described in Table 11–30.
Table 11-30 io Probes
| |
start
| Probe
that fires when an I/O request is about to be made either to a peripheral
device or to an NFS server. The bufinfo_t corresponding
to the I/O request is pointed to by args[0]. The devinfo_t of the device to which the I/O is being issued is pointed to by args[1]. The fileinfo_t of the file that corresponds
to the I/O request is pointed to by args[2]. Note that
file information availability depends on the filesystem making the I/O request.
See fileinfo_t for more information.
|
done
| Probe that fires after an I/O request has been fulfilled. The bufinfo_t corresponding to the I/O request is pointed to by args[0].
The done probe fires after the I/O completes, but before completion processing
has been performed on the buffer. As a result B_DONE is
not set in b_flags at the time the done probe fires. The devinfo_t of the device to which the I/O was issued is pointed to
by args[1]. The fileinfo_t of the file
that corresponds to the I/O request is pointed to by args[2].
|
wait-start
| Probe that fires immediately before a thread begins to wait pending completion of a given I/O
request. The bufinfo_t structure corresponding to the I/O request for which
the thread will wait is pointed to by args[0]. The devinfo_t
of the device to which the I/O was issued is pointed to by args[1]. The
fileinfo_t of the file that corresponds to the I/O request is pointed to by
args[2]. Some time after the wait-start probe fires, the wait-done probe will
fire in the same thread.
|
wait-done
| Probe that fires when a thread is done waiting for the completion of
a given I/O request. The bufinfo_t corresponding to the
I/O request for which the thread will wait is pointed to by args[0].
The devinfo_t of the device to which the I/O was issued
is pointed to by args[1]. The fileinfo_t of
the file that corresponds to the I/O request is pointed to by args[2].
The wait-done probe fires only after the wait-start probe
has fired in the same thread.
|
|
Note that the io probes fire for all I/O requests
to peripheral devices, and for all file read and file write requests to an
NFS server. Requests for metadata from an NFS server, for example, do not
trigger io probes due to a readdir(3C) request.