freebsd-dev/sys/alpha/include/runq.h
Jake Burkholder d2ac231616 Make the run queue parameters machine dependent. Optimize 64 bit
architectures by using a 64 bit word for the bit array which keeps
track of non-empty queues.

Reviewed by:	peter
2002-05-25 01:12:23 +00:00

59 lines
2.0 KiB
C

/*
* Copyright (c) 2001 Jake Burkholder <jake@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _MACHINE_RUNQ_H_
#define _MACHINE_RUNQ_H_
#define RQB_LEN (1UL) /* Number of priority status words. */
#define RQB_L2BPW (6UL) /* Log2(sizeof(rqb_word_t) * NBBY)). */
#define RQB_BPW (1UL<<RQB_L2BPW) /* Bits in an rqb_word_t. */
#define RQB_BIT(pri) (1UL << ((pri) & (RQB_BPW - 1)))
#define RQB_WORD(pri) ((pri) >> RQB_L2BPW)
#define RQB_FFS(word) (ffs64(word))
/*
* Type of run queue status word.
*/
typedef u_int64_t rqb_word_t;
static __inline u_long
ffs64(u_long mask)
{
u_long bit;
if (mask == 0)
return (0);
for (bit = 1; (mask & 1UL) == 0; bit++)
mask >>= 1UL;
return (bit);
}
#endif