linux/include/asm-generic/bitops/sched.h
Mike Galbraith ff80a77f20 sched: simplify sched_find_first_bit()
simplify sched_rt.c's sched_find_first_bit() function: there are
only 100 RT priority levels left.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 18:52:00 +02:00

31 lines
721 B
C

#ifndef _ASM_GENERIC_BITOPS_SCHED_H_
#define _ASM_GENERIC_BITOPS_SCHED_H_
#include <linux/compiler.h> /* unlikely() */
#include <asm/types.h>
/*
* Every architecture must define this function. It's the fastest
* way of searching a 100-bit bitmap. It's guaranteed that at least
* one of the 100 bits is cleared.
*/
static inline int sched_find_first_bit(const unsigned long *b)
{
#if BITS_PER_LONG == 64
if (b[0])
return __ffs(b[0]);
return __ffs(b[1]) + 64;
#elif BITS_PER_LONG == 32
if (b[0])
return __ffs(b[0]);
if (b[1])
return __ffs(b[1]) + 32;
if (b[2])
return __ffs(b[2]) + 64;
return __ffs(b[3]) + 96;
#else
#error BITS_PER_LONG not defined
#endif
}
#endif /* _ASM_GENERIC_BITOPS_SCHED_H_ */