cpu(HW)

Syntax

   #include <sys/ci/cilock.h>
   #include <sys/ci/cimpdata.h>
   #include <sys/ci/ciioctl.h>

Description

These ioctl's are provided on multiprocessor configurations to allow programs to query the number of CPUs that are configured, to lock and unlock processes to specific CPUs, and to enable and disable specific CPUs.

Use these with the ioctl(S) system call. The first argument to ioctl( ) is a file descriptor, returned by an open(S) call to the /dev/at<XX> device, where <XX> is the CPU number.

ACPU_GETNUM

return number of additional CPUs beyond the primary CPU in the int pointed to by arg. For example, on a 4-CPU configuration, this ioctl yields a value of 3.

ACPU_INACTIVE

make the specified CPU be "inactive" (runs no processes); arg is unused.

ACPU_ACTIVE

make the specified CPU be "active" again so that processes can be scheduled to run on this CPU; arg is unused.

ACPU_STATIC

make the specified CPU be "static"; processes will not be scheduled to run on this CPU, but existing processes that are locked to this CPU will run. arg is unused.

ACPU_LOCK

lock a process to the specified CPU. arg is a pointer to an int that contains the pid to lock.

ACPU_UNLOCK

unlock a process; it may then run on any CPU. arg is a pointer to an int that contains the pid to unlock.

ACPU_XLOCK

special Xserver locking (not recommended). arg is unused; the process performing the ioctl locks itself.

ACPU_LED_OFF

Not implemented at this time.

ACPU_LED_BLINK

Not implemented at this time.

ACPU_LED_ON

Not implemented at this time.

See also

For information about binding drivers to a CPU, see the Documentation for the Consolidated Hardware Development Kit, which can be downloaded from the Consolidated Hardware Development (HDK) Web Page. The documentation can be viewed at Documentation Web Page. Select the Open UNIX 8 or UnixWare 7 doc then click on "Hardware and Driver Development". Note especially the idistributed(D3oddi) and remap_driver_cpu(D3oddi) functions.

Examples

Example 1

   #include <sys/ci/cilock.h>
   #include <sys/ci/cimpdata.h>
   #include <sys/ci/ciioctl.h>
   #include <fcntl.h>
   

   	int fd;
   	int num_CPUs;
   

   	if ( (fd = open("/dev/at1", O_RDONLY)) < 0 )
   		perror("/dev/at1");
   		exit(1);
   	}
   

   	if ( ioctl(fd, ACPU_GETNUM, &num_CPUs) < 0 ) {
   		perror("ACPU_GETNUM");
   		exit(1);
   	}
   	printf("Total number of CPUs:  %d\n", num_CPUs + 1);

Example 2

   	int fd;
   	int pid;
   

   	if ( (fd = open("/dev/at2", O_RDONLY)) < 0 ) {
   		perror("/dev/at2");
   		exit(1);
   	}
   

   	pid = (int)getpid();
   	if ( ioctl(fd, ACPU_LOCK, &pid) < 0 ) {
   		perror("ACPU_LOCK");
   		exit(1);
   	}
   

   	printf("Process %d locked to CPU #2\n", pid);