makeiplcookie(9) [netbsd man page]

MAKEIPLCOOKIE(9)					   BSD Kernel Developer's Manual					  MAKEIPLCOOKIE(9)

NAME

     makeiplcookie -- compose an ipl cookie

SYNOPSIS

     #include <sys/param.h>

     ipl_cookie_t
     makeiplcookie(ipl_t ipl);

DESCRIPTION

     makeiplcookie() composes a cookie which can be fed into splraiseipl.  ipl should be one of IPL_ constants.

RETURN VALUES

     makeiplcookie() returns a composed cookie.

SEE ALSO

     spl(9), splraiseipl(9)

BSD
								 December 22, 2006							       BSD

SPLRAISEIPL(9)						   BSD Kernel Developer's Manual					    SPLRAISEIPL(9)

NAME

     splraiseipl -- raise the system priority level

SYNOPSIS

     #include <sys/param.h>

     int
     splraiseipl(ipl_cookie_t icookie);

DESCRIPTION

     splraiseipl() raises the system priority level to the level specified by icookie.	icookie should be a value returned by makeiplcookie().

     In general, device drivers should not make use of this interface.	To ensure correct synchronization, device drivers should use the
     condvar(9), mutex(9), and rwlock(9) interfaces.

     See the spl(9) manual page for a description of interrupt priority levels.

RETURN VALUES

     splraiseipl() returns saved priority level which can be used for splx().

EXAMPLES

     The following two lines are functional equivalents.

	     s = splraiseipl(makeiplcookie(IPL_VM));

	     s = splvm();

     Because makeiplcookie() can be slow and is not expected to be used in a perfomance critical path, it's better to do it beforehand.

	     initialization_code(ipl_t ipl)
	     {

		     ourcookie = makeiplcookie(ipl);
	     }

	     performance_critical_code()
	     {
		     int s;

		     s = splraiseipl(ourcookie);
		     do_something();
		     splx(s);
	     }

SEE ALSO

     condvar(9), makeiplcookie(9), mutex(9), rwlock(9), spl(9)

BSD
								 February 11, 2007							       BSD