kstat_io(9S)
NAME
kstat_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_create(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 ALSO
kstat_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
SunOS 5.5.1 — Last change: 4 Apr 1994