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cpu(HW)


cpu -- SMP ioctl's

Syntax

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

Description

The ioctl's described on this page were provided in previous releases and are no longer supported. They are included here for reference only.

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.
The following ioctls are not implemented at this time:


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

cpuonoff(ADM), lockpid(ADM), mpstat(ADM)

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

The first example illustrates how a process queries the number of CPUs beyond the primary CPU that are configured.
   #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

The second example illustrates how a process locks itself to a particular CPU (/dev/at2 in this case). This uses the same #include files shown in Example 1.
   	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);


© 2005 The SCO Group, Inc. All rights reserved.
SCO OpenServer Release 6.0.0 -- 03 June 2005