unix_master(9r) 														   unix_master(9r)

NAME

       unix_master - General: Forces execution onto the master CPU

SYNOPSIS

       void unix_master(
	       void );

ARGUMENTS

       None

DESCRIPTION

       The  unix_master  routine forces execution of the kernel thread onto the master CPU (also called the boot CPU). In other words, unix_master
       binds the kernel thread to the master CPU. To release the kernel thread from the bind to the master CPU, call the unix_release routine. You
       can make recursive calls to unix_master as long as you make an equal number of calls to unix_release.

       The unix_master routine provides another way besides the simple and complex lock routines to make a kernel module symmetric multiprocessing
       (SMP) safe. Although calling unix_master is not optimal for performance on an SMP CPU, it does provide third-party  kernel  module  writers
       with an easy way to make their modules SMP safe without using the lock routines.

NOTES

       Device  drivers should not directly call the unix_master and unix_release routines. One exception to this recommendation is when you want a
       device driver's kernel threads to run only on the master CPU. This situation occurs when your driver creates  and  starts  its  own  kernel
       threads	and  you  set the d_funnel member of the associated dsent structure to the value DEV_FUNNEL. In this case, each kernel thread must
       call unix_master once to ensure that the kernel thread runs only on the master CPU. Remember to make a corresponding call to unix_release.

CAUTIONS

       To avoid deadlock, do not call the unix_master routine under the following circumstances: When holding a simple lock In the driver's inter-
       rupt service routine

RETURN VALUES

       None

SEE ALSO

       routines: unix_release(9r)

																   unix_master(9r)