runq.h revision 208283
1/*- 2 * Copyright (c) 2001 Jake Burkholder <jake@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: head/sys/ia64/include/runq.h 208283 2010-05-19 00:23:10Z marcel $ 27 */ 28 29#ifndef _MACHINE_RUNQ_H_ 30#define _MACHINE_RUNQ_H_ 31 32#define RQB_LEN (1UL) /* Number of priority status words. */ 33#define RQB_L2BPW (6UL) /* Log2(sizeof(rqb_word_t) * NBBY)). */ 34#define RQB_BPW (1UL<<RQB_L2BPW) /* Bits in an rqb_word_t. */ 35 36#define RQB_BIT(pri) (1UL << ((pri) & (RQB_BPW - 1))) 37#define RQB_WORD(pri) ((pri) >> RQB_L2BPW) 38 39#define RQB_FFS(word) (__ffsl(word) - 1) 40 41/* 42 * Type of run queue status word. 43 */ 44typedef uint64_t rqb_word_t; 45 46static __inline uint64_t 47__popcnt(uint64_t bits) 48{ 49 uint64_t result; 50 51 __asm __volatile("popcnt %0=%1" : "=r" (result) : "r" (bits)); 52 return result; 53} 54 55 56static __inline int 57__ffsl(u_long mask) 58{ 59 60 if (__predict_false(mask == 0ul)) 61 return (0); 62 return (__popcnt(mask ^ (mask - 1))); 63} 64 65#endif 66