KSTAT_IO(9S)KSTAT_IO(9S)NAMEkstat_io - structure for I/O kstats
SYNOPSIS
#include <sys/types.h>
#include <sys/kstat.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
INTERFACE LEVEL
Solaris DDI specific (Solaris DDI)
DESCRIPTION
I/O kstat statistics are kept in a kstat_io structure. When kstat_cre‐
ate(9F) creates an I/O kstat, the ks_data field is a pointer to one of
these structures. The macro KSTAT_IO_PTR() is provided to retrieve this
field. It looks like this:
#define KSTAT_IO_PTR(kptr) ((kstat_io_t *)(kptr)->ks_data)
STRUCTURE MEMBERS
u_longlong_t nread; /* number of bytes read */
u_longlong_t nwritten; /* number of bytes written *]/
ulong_t reads; /* number of read operations */
ulong_t writes; /* number of write operations */
The nread field should be updated by the driver with the number of
bytes successfully read upon completion.
The nwritten field should be updated by the driver with the number of
bytes successfully written upon completion.
The reads field should be updated by the driver after each successful
read operation.
The writes field should be updated by the driver after each successful
write operation.
Other I/O statistics are updated through the use of the kstat_queue(9F)
functions.
SEE ALSOkstat_create(9F), kstat_named_init(9F), kstat_queue(9F),
kstat_runq_back_to_waitq(9F), kstat_runq_enter(9F),
kstat_runq_exit(9F), kstat_waitq_enter(9F), kstat_waitq_exit(9F),
kstat_waitq_to_runq(9F)
Writing Device Drivers
Apr 4, 1994 KSTAT_IO(9S)
