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#include <sys/types.h> #include <sys/kstat.h> kstat_t *kstat_create(const char *ks_module, int ks_instance, const char *ks_name, const char *ks_class, uchar_t ks_type, ulong_t ks_ndata, uchar_t ks_flag);
Solaris DDI specific (Solaris DDI)
ks_module
The name of the provider's module (such as "sd", "esp", ...). The "core" kernel uses the name "unix".
ks_instance
The provider's instance number, as from ddi_get_instance(9F). Modules which do not have a meaningful instance number should use 0.
ks_name
A pointer to a string that uniquely identifies this structure. Only KSTAT_STRLEN - 1 characters are significant.
ks_class
The general class that this kstat belongs to. The following classes are currently in use: disk, tape, net, controller, vm, kvm, hat, streams, kstat, and misc.
ks_type
The type of kstat to allocate. Valid types are:
KSTAT_TYPE_NAMED
Allows more than one data record per kstat.
KSTAT_TYPE_INTR
Interrupt; only one data record per kstat.
KSTAT_TYPE_IO
I/O; only one data record per kstat
ks_ndata
The number of type-specific data records to allocate.
ks_flag
A bit-field of various flags for this kstat. ks_flag is some combination of:
KSTAT_FLAG_VIRTUAL
Tells kstat_create() not to allocate memory for the kstat data section; instead, the driver will set the ks_data field to point to the data it wishes to export. This provides a convenient way to export existing data structures.
KSTAT_FLAG_WRITABLE
Makes the kstat data section writable by root.
KSTAT_FLAG_PERSISTENT
Indicates that this kstat is to be persistent over time. For persistent kstats, kstat_delete(9F) simply marks the kstat as dormant; a subsequent kstat_create() reactivates the kstat. This feature is provided so that statistics are not lost across driver close/open (such as raw disk I/O on a disk with no mounted partitions.) Note: Persistent kstats cannot be virtual, since ks_data points to garbage as soon as the driver goes away.
kstat_create() is used in conjunction with kstat_install(9F) to allocate and initialize a kstat(9S) structure. The method is generally as follows:
kstat_create() allocates and performs necessary system initialization of a kstat(9S) structure. kstat_create() allocates memory for the entire kstat (header plus data), initializes all header fields, initializes the data section to all zeroes, assigns a unique kstat ID (KID), and puts the kstat onto the system's kstat chain. The returned kstat is marked invalid because the provider (caller) has not yet had a chance to initialize the data section.
After a successful call to kstat_create() the driver must perform any necessary initialization of the data section (such as setting the name fields in a kstat of type KSTAT_TYPE_NAMED). Virtual kstats must have the ks_data field set at this time. The provider may also set the ks_update, ks_private, and ks_lock fields if necessary.
Once the kstat is completely initialized, kstat_install(9F) is used to make the kstat accessible to the outside world.
If successful, kstat_create() returns a pointer to the allocated kstat. NULL is returned upon failure.
kstat_create() can be called from user or kernel context.
Example 1 Allocating and Initializing a kstat Structure
pkstat_t *ksp;
ksp = kstat_create(module, instance, name, class, type, ndata, flags);
if (ksp) {
/* ... provider initialization, if necessary */
kstat_install(ksp);
}
kstat(3KSTAT), ddi_get_instance(9F), kstat_delete(9F), kstat_install(9F), kstat_named_init(9F), kstat(9S), kstat_named(9S)
Writing Device Drivers