1/*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. 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 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30#if 0 31#ifndef lint 32static char sccsid[] = "@(#)proc_compare.c 8.2 (Berkeley) 9/23/93"; 33#endif /* not lint */ 34#endif 35 36#include <sys/cdefs.h> 37#ifndef __APPLE__ 38__FBSDID("$FreeBSD: src/usr.bin/w/proc_compare.c,v 1.9 2004/04/14 09:34:17 bde Exp $"); 39#endif 40 41#include <sys/param.h> 42#ifdef __APPLE__ 43#include <sys/time.h> 44#endif 45#include <sys/proc.h> 46#include <sys/time.h> 47#include <sys/user.h> 48 49#include "extern.h" 50 51/* 52 * Returns 1 if p2 is "better" than p1 53 * 54 * The algorithm for picking the "interesting" process is thus: 55 * 56 * 1) Only foreground processes are eligible - implied. 57 * 2) Runnable processes are favored over anything else. The runner 58 * with the highest cpu utilization is picked (p_estcpu). Ties are 59 * broken by picking the highest pid. 60 * 3) The sleeper with the shortest sleep time is next. With ties, 61 * we pick out just "short-term" sleepers (TDF_SINTR == 0). 62 * 4) Further ties are broken by picking the highest pid. 63 * 64 * If you change this, be sure to consider making the change in the kernel 65 * too (^T in kern/tty.c). 66 * 67 * TODO - consider whether pctcpu should be used. 68 */ 69 70#if !HAVE_KVM 71#define ki_estcpu p_estcpu 72#define ki_pid p_pid 73#define ki_slptime p_slptime 74#define ki_stat p_stat 75#define ki_tdflags p_tdflags 76#endif 77 78#define ISRUN(p) (((p)->ki_stat == SRUN) || ((p)->ki_stat == SIDL)) 79#define TESTAB(a, b) ((a)<<1 | (b)) 80#define ONLYA 2 81#define ONLYB 1 82#define BOTH 3 83 84#if HAVE_KVM 85int 86proc_compare(struct kinfo_proc *p1, struct kinfo_proc *p2) 87{ 88#else 89int 90proc_compare(struct kinfo_proc *arg1, struct kinfo_proc *arg2) 91{ 92 struct extern_proc* p1 = &arg1->kp_proc; 93 struct extern_proc* p2 = &arg2->kp_proc; 94#endif 95 96 if (p1 == NULL) 97 return (1); 98 /* 99 * see if at least one of them is runnable 100 */ 101 switch (TESTAB(ISRUN(p1), ISRUN(p2))) { 102 case ONLYA: 103 return (0); 104 case ONLYB: 105 return (1); 106 case BOTH: 107 /* 108 * tie - favor one with highest recent cpu utilization 109 */ 110 if (p2->ki_estcpu > p1->ki_estcpu) 111 return (1); 112 if (p1->ki_estcpu > p2->ki_estcpu) 113 return (0); 114 return (p2->ki_pid > p1->ki_pid); /* tie - return highest pid */ 115 } 116 /* 117 * weed out zombies 118 */ 119 switch (TESTAB(p1->ki_stat == SZOMB, p2->ki_stat == SZOMB)) { 120 case ONLYA: 121 return (1); 122 case ONLYB: 123 return (0); 124 case BOTH: 125 return (p2->ki_pid > p1->ki_pid); /* tie - return highest pid */ 126 } 127 /* 128 * pick the one with the smallest sleep time 129 */ 130 if (p2->ki_slptime > p1->ki_slptime) 131 return (0); 132 if (p1->ki_slptime > p2->ki_slptime) 133 return (1); 134#ifndef __APPLE__ 135 /* 136 * favor one sleeping in a non-interruptible sleep 137 */ 138 if (p1->ki_tdflags & TDF_SINTR && (p2->ki_tdflags & TDF_SINTR) == 0) 139 return (1); 140 if (p2->ki_tdflags & TDF_SINTR && (p1->ki_tdflags & TDF_SINTR) == 0) 141 return (0); 142#endif 143 return (p2->ki_pid > p1->ki_pid); /* tie - return highest pid */ 144} 145