tty_info.c revision 330897
1/*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1990, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Copyright (c) 2002 Networks Associates Technologies, Inc. 13 * All rights reserved. 14 * 15 * Portions of this software were developed for the FreeBSD Project by 16 * ThinkSec AS and NAI Labs, the Security Research Division of Network 17 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 18 * ("CBOSS"), as part of the DARPA CHATS research program. 19 * 20 * Redistribution and use in source and binary forms, with or without 21 * modification, are permitted provided that the following conditions 22 * are met: 23 * 1. Redistributions of source code must retain the above copyright 24 * notice, this list of conditions and the following disclaimer. 25 * 2. Redistributions in binary form must reproduce the above copyright 26 * notice, this list of conditions and the following disclaimer in the 27 * documentation and/or other materials provided with the distribution. 28 * 4. Neither the name of the University nor the names of its contributors 29 * may be used to endorse or promote products derived from this software 30 * without specific prior written permission. 31 * 32 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 33 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 34 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 35 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 36 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 40 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 41 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 42 * SUCH DAMAGE. 43 */ 44 45#include <sys/cdefs.h> 46__FBSDID("$FreeBSD: stable/11/sys/kern/tty_info.c 330897 2018-03-14 03:19:51Z eadler $"); 47 48#include <sys/param.h> 49#include <sys/lock.h> 50#include <sys/mutex.h> 51#include <sys/proc.h> 52#include <sys/resourcevar.h> 53#include <sys/sched.h> 54#include <sys/systm.h> 55#include <sys/tty.h> 56 57#include <vm/vm.h> 58#include <vm/pmap.h> 59#include <vm/vm_map.h> 60 61/* 62 * Returns 1 if p2 is "better" than p1 63 * 64 * The algorithm for picking the "interesting" process is thus: 65 * 66 * 1) Only foreground processes are eligible - implied. 67 * 2) Runnable processes are favored over anything else. The runner 68 * with the highest cpu utilization is picked (p_estcpu). Ties are 69 * broken by picking the highest pid. 70 * 3) The sleeper with the shortest sleep time is next. With ties, 71 * we pick out just "short-term" sleepers (P_SINTR == 0). 72 * 4) Further ties are broken by picking the highest pid. 73 */ 74 75#define TESTAB(a, b) ((a)<<1 | (b)) 76#define ONLYA 2 77#define ONLYB 1 78#define BOTH 3 79 80static int 81proc_sum(struct proc *p, fixpt_t *estcpup) 82{ 83 struct thread *td; 84 int estcpu; 85 int val; 86 87 val = 0; 88 estcpu = 0; 89 FOREACH_THREAD_IN_PROC(p, td) { 90 thread_lock(td); 91 if (TD_ON_RUNQ(td) || 92 TD_IS_RUNNING(td)) 93 val = 1; 94 estcpu += sched_pctcpu(td); 95 thread_unlock(td); 96 } 97 *estcpup = estcpu; 98 99 return (val); 100} 101 102static int 103thread_compare(struct thread *td, struct thread *td2) 104{ 105 int runa, runb; 106 int slpa, slpb; 107 fixpt_t esta, estb; 108 109 if (td == NULL) 110 return (1); 111 112 /* 113 * Fetch running stats, pctcpu usage, and interruptable flag. 114 */ 115 thread_lock(td); 116 runa = TD_IS_RUNNING(td) | TD_ON_RUNQ(td); 117 slpa = td->td_flags & TDF_SINTR; 118 esta = sched_pctcpu(td); 119 thread_unlock(td); 120 thread_lock(td2); 121 runb = TD_IS_RUNNING(td2) | TD_ON_RUNQ(td2); 122 estb = sched_pctcpu(td2); 123 slpb = td2->td_flags & TDF_SINTR; 124 thread_unlock(td2); 125 /* 126 * see if at least one of them is runnable 127 */ 128 switch (TESTAB(runa, runb)) { 129 case ONLYA: 130 return (0); 131 case ONLYB: 132 return (1); 133 case BOTH: 134 break; 135 } 136 /* 137 * favor one with highest recent cpu utilization 138 */ 139 if (estb > esta) 140 return (1); 141 if (esta > estb) 142 return (0); 143 /* 144 * favor one sleeping in a non-interruptible sleep 145 */ 146 switch (TESTAB(slpa, slpb)) { 147 case ONLYA: 148 return (0); 149 case ONLYB: 150 return (1); 151 case BOTH: 152 break; 153 } 154 155 return (td < td2); 156} 157 158static int 159proc_compare(struct proc *p1, struct proc *p2) 160{ 161 162 int runa, runb; 163 fixpt_t esta, estb; 164 165 if (p1 == NULL) 166 return (1); 167 168 /* 169 * Fetch various stats about these processes. After we drop the 170 * lock the information could be stale but the race is unimportant. 171 */ 172 PROC_LOCK(p1); 173 runa = proc_sum(p1, &esta); 174 PROC_UNLOCK(p1); 175 PROC_LOCK(p2); 176 runb = proc_sum(p2, &estb); 177 PROC_UNLOCK(p2); 178 179 /* 180 * see if at least one of them is runnable 181 */ 182 switch (TESTAB(runa, runb)) { 183 case ONLYA: 184 return (0); 185 case ONLYB: 186 return (1); 187 case BOTH: 188 break; 189 } 190 /* 191 * favor one with highest recent cpu utilization 192 */ 193 if (estb > esta) 194 return (1); 195 if (esta > estb) 196 return (0); 197 /* 198 * weed out zombies 199 */ 200 switch (TESTAB(p1->p_state == PRS_ZOMBIE, p2->p_state == PRS_ZOMBIE)) { 201 case ONLYA: 202 return (1); 203 case ONLYB: 204 return (0); 205 case BOTH: 206 break; 207 } 208 209 return (p2->p_pid > p1->p_pid); /* tie - return highest pid */ 210} 211 212/* 213 * Report on state of foreground process group. 214 */ 215void 216tty_info(struct tty *tp) 217{ 218 struct timeval rtime, utime, stime; 219 struct proc *p, *ppick; 220 struct thread *td, *tdpick; 221 const char *stateprefix, *state; 222 long rss; 223 int load, pctcpu; 224 pid_t pid; 225 char comm[MAXCOMLEN + 1]; 226 struct rusage ru; 227 228 tty_lock_assert(tp, MA_OWNED); 229 230 if (tty_checkoutq(tp) == 0) 231 return; 232 233 /* Print load average. */ 234 load = (averunnable.ldavg[0] * 100 + FSCALE / 2) >> FSHIFT; 235 ttyprintf(tp, "%sload: %d.%02d ", tp->t_column == 0 ? "" : "\n", 236 load / 100, load % 100); 237 238 if (tp->t_session == NULL) { 239 ttyprintf(tp, "not a controlling terminal\n"); 240 return; 241 } 242 if (tp->t_pgrp == NULL) { 243 ttyprintf(tp, "no foreground process group\n"); 244 return; 245 } 246 PGRP_LOCK(tp->t_pgrp); 247 if (LIST_EMPTY(&tp->t_pgrp->pg_members)) { 248 PGRP_UNLOCK(tp->t_pgrp); 249 ttyprintf(tp, "empty foreground process group\n"); 250 return; 251 } 252 253 /* 254 * Pick the most interesting process and copy some of its 255 * state for printing later. This operation could rely on stale 256 * data as we can't hold the proc slock or thread locks over the 257 * whole list. However, we're guaranteed not to reference an exited 258 * thread or proc since we hold the tty locked. 259 */ 260 p = NULL; 261 LIST_FOREACH(ppick, &tp->t_pgrp->pg_members, p_pglist) 262 if (proc_compare(p, ppick)) 263 p = ppick; 264 265 PROC_LOCK(p); 266 PGRP_UNLOCK(tp->t_pgrp); 267 td = NULL; 268 FOREACH_THREAD_IN_PROC(p, tdpick) 269 if (thread_compare(td, tdpick)) 270 td = tdpick; 271 stateprefix = ""; 272 thread_lock(td); 273 if (TD_IS_RUNNING(td)) 274 state = "running"; 275 else if (TD_ON_RUNQ(td) || TD_CAN_RUN(td)) 276 state = "runnable"; 277 else if (TD_IS_SLEEPING(td)) { 278 /* XXX: If we're sleeping, are we ever not in a queue? */ 279 if (TD_ON_SLEEPQ(td)) 280 state = td->td_wmesg; 281 else 282 state = "sleeping without queue"; 283 } else if (TD_ON_LOCK(td)) { 284 state = td->td_lockname; 285 stateprefix = "*"; 286 } else if (TD_IS_SUSPENDED(td)) 287 state = "suspended"; 288 else if (TD_AWAITING_INTR(td)) 289 state = "intrwait"; 290 else if (p->p_state == PRS_ZOMBIE) 291 state = "zombie"; 292 else 293 state = "unknown"; 294 pctcpu = (sched_pctcpu(td) * 10000 + FSCALE / 2) >> FSHIFT; 295 thread_unlock(td); 296 if (p->p_state == PRS_NEW || p->p_state == PRS_ZOMBIE) 297 rss = 0; 298 else 299 rss = pgtok(vmspace_resident_count(p->p_vmspace)); 300 microuptime(&rtime); 301 timevalsub(&rtime, &p->p_stats->p_start); 302 rufetchcalc(p, &ru, &utime, &stime); 303 pid = p->p_pid; 304 strlcpy(comm, p->p_comm, sizeof comm); 305 PROC_UNLOCK(p); 306 307 /* Print command, pid, state, rtime, utime, stime, %cpu, and rss. */ 308 ttyprintf(tp, 309 " cmd: %s %d [%s%s] %ld.%02ldr %ld.%02ldu %ld.%02lds %d%% %ldk\n", 310 comm, pid, stateprefix, state, 311 (long)rtime.tv_sec, rtime.tv_usec / 10000, 312 (long)utime.tv_sec, utime.tv_usec / 10000, 313 (long)stime.tv_sec, stime.tv_usec / 10000, 314 pctcpu / 100, rss); 315} 316