1 /* $NetBSD: kern_synch.c,v 1.38 1996/07/17 21:54:06 explorer Exp $ */ 2 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 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)kern_synch.c 8.6 (Berkeley) 1/21/94 41 */ 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/proc.h> 46 #include <sys/kernel.h> 47 #include <sys/buf.h> 48 #include <sys/signalvar.h> 49 #include <sys/resourcevar.h> 50 #include <vm/vm.h> 51 #ifdef KTRACE 52 #include <sys/ktrace.h> 53 #endif 54 55 #include <machine/cpu.h> 56 57 u_char curpriority; /* usrpri of curproc */ 58 int lbolt; /* once a second sleep address */ 59 60 void roundrobin __P((void *)); 61 void schedcpu __P((void *)); 62 void updatepri __P((struct proc *)); 63 void endtsleep __P((void *)); 64 65 /* 66 * Force switch among equal priority processes every 100ms. 67 */ 68 /* ARGSUSED */ 69 void 70 roundrobin(arg) 71 void *arg; 72 { 73 74 need_resched(); 75 timeout(roundrobin, NULL, hz / 10); 76 } 77 78 /* 79 * Constants for digital decay and forget: 80 * 90% of (p_estcpu) usage in 5 * loadav time 81 * 95% of (p_pctcpu) usage in 60 seconds (load insensitive) 82 * Note that, as ps(1) mentions, this can let percentages 83 * total over 100% (I've seen 137.9% for 3 processes). 84 * 85 * Note that hardclock updates p_estcpu and p_cpticks independently. 86 * 87 * We wish to decay away 90% of p_estcpu in (5 * loadavg) seconds. 88 * That is, the system wants to compute a value of decay such 89 * that the following for loop: 90 * for (i = 0; i < (5 * loadavg); i++) 91 * p_estcpu *= decay; 92 * will compute 93 * p_estcpu *= 0.1; 94 * for all values of loadavg: 95 * 96 * Mathematically this loop can be expressed by saying: 97 * decay ** (5 * loadavg) ~= .1 98 * 99 * The system computes decay as: 100 * decay = (2 * loadavg) / (2 * loadavg + 1) 101 * 102 * We wish to prove that the system's computation of decay 103 * will always fulfill the equation: 104 * decay ** (5 * loadavg) ~= .1 105 * 106 * If we compute b as: 107 * b = 2 * loadavg 108 * then 109 * decay = b / (b + 1) 110 * 111 * We now need to prove two things: 112 * 1) Given factor ** (5 * loadavg) ~= .1, prove factor == b/(b+1) 113 * 2) Given b/(b+1) ** power ~= .1, prove power == (5 * loadavg) 114 * 115 * Facts: 116 * For x close to zero, exp(x) =~ 1 + x, since 117 * exp(x) = 0! + x**1/1! + x**2/2! + ... . 118 * therefore exp(-1/b) =~ 1 - (1/b) = (b-1)/b. 119 * For x close to zero, ln(1+x) =~ x, since 120 * ln(1+x) = x - x**2/2 + x**3/3 - ... -1 < x < 1 121 * therefore ln(b/(b+1)) = ln(1 - 1/(b+1)) =~ -1/(b+1). 122 * ln(.1) =~ -2.30 123 * 124 * Proof of (1): 125 * Solve (factor)**(power) =~ .1 given power (5*loadav): 126 * solving for factor, 127 * ln(factor) =~ (-2.30/5*loadav), or 128 * factor =~ exp(-1/((5/2.30)*loadav)) =~ exp(-1/(2*loadav)) = 129 * exp(-1/b) =~ (b-1)/b =~ b/(b+1). QED 130 * 131 * Proof of (2): 132 * Solve (factor)**(power) =~ .1 given factor == (b/(b+1)): 133 * solving for power, 134 * power*ln(b/(b+1)) =~ -2.30, or 135 * power =~ 2.3 * (b + 1) = 4.6*loadav + 2.3 =~ 5*loadav. QED 136 * 137 * Actual power values for the implemented algorithm are as follows: 138 * loadav: 1 2 3 4 139 * power: 5.68 10.32 14.94 19.55 140 */ 141 142 /* calculations for digital decay to forget 90% of usage in 5*loadav sec */ 143 #define loadfactor(loadav) (2 * (loadav)) 144 #define decay_cpu(loadfac, cpu) (((loadfac) * (cpu)) / ((loadfac) + FSCALE)) 145 146 /* decay 95% of `p_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */ 147 fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */ 148 149 /* 150 * If `ccpu' is not equal to `exp(-1/20)' and you still want to use the 151 * faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below 152 * and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT). 153 * 154 * To estimate CCPU_SHIFT for exp(-1/20), the following formula was used: 155 * 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits). 156 * 157 * If you dont want to bother with the faster/more-accurate formula, you 158 * can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate 159 * (more general) method of calculating the %age of CPU used by a process. 160 */ 161 #define CCPU_SHIFT 11 162 163 /* 164 * Recompute process priorities, every hz ticks. 165 */ 166 /* ARGSUSED */ 167 void 168 schedcpu(arg) 169 void *arg; 170 { 171 register fixpt_t loadfac = loadfactor(averunnable.ldavg[0]); 172 register struct proc *p; 173 register int s; 174 register unsigned int newcpu; 175 176 wakeup((caddr_t)&lbolt); 177 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 178 /* 179 * Increment time in/out of memory and sleep time 180 * (if sleeping). We ignore overflow; with 16-bit int's 181 * (remember them?) overflow takes 45 days. 182 */ 183 p->p_swtime++; 184 if (p->p_stat == SSLEEP || p->p_stat == SSTOP) 185 p->p_slptime++; 186 p->p_pctcpu = (p->p_pctcpu * ccpu) >> FSHIFT; 187 /* 188 * If the process has slept the entire second, 189 * stop recalculating its priority until it wakes up. 190 */ 191 if (p->p_slptime > 1) 192 continue; 193 s = splstatclock(); /* prevent state changes */ 194 /* 195 * p_pctcpu is only for ps. 196 */ 197 #if (FSHIFT >= CCPU_SHIFT) 198 p->p_pctcpu += (hz == 100)? 199 ((fixpt_t) p->p_cpticks) << (FSHIFT - CCPU_SHIFT): 200 100 * (((fixpt_t) p->p_cpticks) 201 << (FSHIFT - CCPU_SHIFT)) / hz; 202 #else 203 p->p_pctcpu += ((FSCALE - ccpu) * 204 (p->p_cpticks * FSCALE / hz)) >> FSHIFT; 205 #endif 206 p->p_cpticks = 0; 207 newcpu = (u_int) decay_cpu(loadfac, p->p_estcpu) + p->p_nice; 208 p->p_estcpu = min(newcpu, UCHAR_MAX); 209 resetpriority(p); 210 if (p->p_priority >= PUSER) { 211 #define PPQ (128 / NQS) /* priorities per queue */ 212 if ((p != curproc) && 213 p->p_stat == SRUN && 214 (p->p_flag & P_INMEM) && 215 (p->p_priority / PPQ) != (p->p_usrpri / PPQ)) { 216 remrq(p); 217 p->p_priority = p->p_usrpri; 218 setrunqueue(p); 219 } else 220 p->p_priority = p->p_usrpri; 221 } 222 splx(s); 223 } 224 vmmeter(); 225 if (bclnlist != NULL) 226 wakeup((caddr_t)pageproc); 227 timeout(schedcpu, (void *)0, hz); 228 } 229 230 /* 231 * Recalculate the priority of a process after it has slept for a while. 232 * For all load averages >= 1 and max p_estcpu of 255, sleeping for at 233 * least six times the loadfactor will decay p_estcpu to zero. 234 */ 235 void 236 updatepri(p) 237 register struct proc *p; 238 { 239 register unsigned int newcpu = p->p_estcpu; 240 register fixpt_t loadfac = loadfactor(averunnable.ldavg[0]); 241 242 if (p->p_slptime > 5 * loadfac) 243 p->p_estcpu = 0; 244 else { 245 p->p_slptime--; /* the first time was done in schedcpu */ 246 while (newcpu && --p->p_slptime) 247 newcpu = (int) decay_cpu(loadfac, newcpu); 248 p->p_estcpu = min(newcpu, UCHAR_MAX); 249 } 250 resetpriority(p); 251 } 252 253 /* 254 * We're only looking at 7 bits of the address; everything is 255 * aligned to 4, lots of things are aligned to greater powers 256 * of 2. Shift right by 8, i.e. drop the bottom 256 worth. 257 */ 258 #define TABLESIZE 128 259 #define LOOKUP(x) (((long)(x) >> 8) & (TABLESIZE - 1)) 260 struct slpque { 261 struct proc *sq_head; 262 struct proc **sq_tailp; 263 } slpque[TABLESIZE]; 264 265 /* 266 * During autoconfiguration or after a panic, a sleep will simply 267 * lower the priority briefly to allow interrupts, then return. 268 * The priority to be used (safepri) is machine-dependent, thus this 269 * value is initialized and maintained in the machine-dependent layers. 270 * This priority will typically be 0, or the lowest priority 271 * that is safe for use on the interrupt stack; it can be made 272 * higher to block network software interrupts after panics. 273 */ 274 int safepri; 275 276 /* 277 * General sleep call. Suspends the current process until a wakeup is 278 * performed on the specified identifier. The process will then be made 279 * runnable with the specified priority. Sleeps at most timo/hz seconds 280 * (0 means no timeout). If pri includes PCATCH flag, signals are checked 281 * before and after sleeping, else signals are not checked. Returns 0 if 282 * awakened, EWOULDBLOCK if the timeout expires. If PCATCH is set and a 283 * signal needs to be delivered, ERESTART is returned if the current system 284 * call should be restarted if possible, and EINTR is returned if the system 285 * call should be interrupted by the signal (return EINTR). 286 */ 287 int 288 tsleep(ident, priority, wmesg, timo) 289 void *ident; 290 int priority, timo; 291 char *wmesg; 292 { 293 register struct proc *p = curproc; 294 register struct slpque *qp; 295 register s; 296 int sig, catch = priority & PCATCH; 297 extern int cold; 298 void endtsleep __P((void *)); 299 300 #ifdef KTRACE 301 if (KTRPOINT(p, KTR_CSW)) 302 ktrcsw(p->p_tracep, 1, 0); 303 #endif 304 s = splhigh(); 305 if (cold || panicstr) { 306 /* 307 * After a panic, or during autoconfiguration, 308 * just give interrupts a chance, then just return; 309 * don't run any other procs or panic below, 310 * in case this is the idle process and already asleep. 311 */ 312 splx(safepri); 313 splx(s); 314 return (0); 315 } 316 #ifdef DIAGNOSTIC 317 if (ident == NULL || p->p_stat != SRUN || p->p_back) 318 panic("tsleep"); 319 #endif 320 p->p_wchan = ident; 321 p->p_wmesg = wmesg; 322 p->p_slptime = 0; 323 p->p_priority = priority & PRIMASK; 324 qp = &slpque[LOOKUP(ident)]; 325 if (qp->sq_head == 0) 326 qp->sq_head = p; 327 else 328 *qp->sq_tailp = p; 329 *(qp->sq_tailp = &p->p_forw) = 0; 330 if (timo) 331 timeout(endtsleep, (void *)p, timo); 332 /* 333 * We put ourselves on the sleep queue and start our timeout 334 * before calling CURSIG, as we could stop there, and a wakeup 335 * or a SIGCONT (or both) could occur while we were stopped. 336 * A SIGCONT would cause us to be marked as SSLEEP 337 * without resuming us, thus we must be ready for sleep 338 * when CURSIG is called. If the wakeup happens while we're 339 * stopped, p->p_wchan will be 0 upon return from CURSIG. 340 */ 341 if (catch) { 342 p->p_flag |= P_SINTR; 343 if ((sig = CURSIG(p)) != 0) { 344 if (p->p_wchan) 345 unsleep(p); 346 p->p_stat = SRUN; 347 goto resume; 348 } 349 if (p->p_wchan == 0) { 350 catch = 0; 351 goto resume; 352 } 353 } else 354 sig = 0; 355 p->p_stat = SSLEEP; 356 p->p_stats->p_ru.ru_nvcsw++; 357 mi_switch(); 358 #ifdef DDB 359 /* handy breakpoint location after process "wakes" */ 360 asm(".globl bpendtsleep ; bpendtsleep:"); 361 #endif 362 resume: 363 curpriority = p->p_usrpri; 364 splx(s); 365 p->p_flag &= ~P_SINTR; 366 if (p->p_flag & P_TIMEOUT) { 367 p->p_flag &= ~P_TIMEOUT; 368 if (sig == 0) { 369 #ifdef KTRACE 370 if (KTRPOINT(p, KTR_CSW)) 371 ktrcsw(p->p_tracep, 0, 0); 372 #endif 373 return (EWOULDBLOCK); 374 } 375 } else if (timo) 376 untimeout(endtsleep, (void *)p); 377 if (catch && (sig != 0 || (sig = CURSIG(p)) != 0)) { 378 #ifdef KTRACE 379 if (KTRPOINT(p, KTR_CSW)) 380 ktrcsw(p->p_tracep, 0, 0); 381 #endif 382 if (p->p_sigacts->ps_sigintr & sigmask(sig)) 383 return (EINTR); 384 return (ERESTART); 385 } 386 #ifdef KTRACE 387 if (KTRPOINT(p, KTR_CSW)) 388 ktrcsw(p->p_tracep, 0, 0); 389 #endif 390 return (0); 391 } 392 393 /* 394 * Implement timeout for tsleep. 395 * If process hasn't been awakened (wchan non-zero), 396 * set timeout flag and undo the sleep. If proc 397 * is stopped, just unsleep so it will remain stopped. 398 */ 399 void 400 endtsleep(arg) 401 void *arg; 402 { 403 register struct proc *p; 404 int s; 405 406 p = (struct proc *)arg; 407 s = splhigh(); 408 if (p->p_wchan) { 409 if (p->p_stat == SSLEEP) 410 setrunnable(p); 411 else 412 unsleep(p); 413 p->p_flag |= P_TIMEOUT; 414 } 415 splx(s); 416 } 417 418 /* 419 * Short-term, non-interruptable sleep. 420 */ 421 void 422 sleep(ident, priority) 423 void *ident; 424 int priority; 425 { 426 register struct proc *p = curproc; 427 register struct slpque *qp; 428 register s; 429 extern int cold; 430 431 #ifdef DIAGNOSTIC 432 if (priority > PZERO) { 433 printf("sleep called with priority %d > PZERO, wchan: %p\n", 434 priority, ident); 435 panic("old sleep"); 436 } 437 #endif 438 s = splhigh(); 439 if (cold || panicstr) { 440 /* 441 * After a panic, or during autoconfiguration, 442 * just give interrupts a chance, then just return; 443 * don't run any other procs or panic below, 444 * in case this is the idle process and already asleep. 445 */ 446 splx(safepri); 447 splx(s); 448 return; 449 } 450 #ifdef DIAGNOSTIC 451 if (ident == NULL || p->p_stat != SRUN || p->p_back) 452 panic("sleep"); 453 #endif 454 p->p_wchan = ident; 455 p->p_wmesg = NULL; 456 p->p_slptime = 0; 457 p->p_priority = priority; 458 qp = &slpque[LOOKUP(ident)]; 459 if (qp->sq_head == 0) 460 qp->sq_head = p; 461 else 462 *qp->sq_tailp = p; 463 *(qp->sq_tailp = &p->p_forw) = 0; 464 p->p_stat = SSLEEP; 465 p->p_stats->p_ru.ru_nvcsw++; 466 #ifdef KTRACE 467 if (KTRPOINT(p, KTR_CSW)) 468 ktrcsw(p->p_tracep, 1, 0); 469 #endif 470 mi_switch(); 471 #ifdef DDB 472 /* handy breakpoint location after process "wakes" */ 473 asm(".globl bpendsleep ; bpendsleep:"); 474 #endif 475 #ifdef KTRACE 476 if (KTRPOINT(p, KTR_CSW)) 477 ktrcsw(p->p_tracep, 0, 0); 478 #endif 479 curpriority = p->p_usrpri; 480 splx(s); 481 } 482 483 /* 484 * Remove a process from its wait queue 485 */ 486 void 487 unsleep(p) 488 register struct proc *p; 489 { 490 register struct slpque *qp; 491 register struct proc **hp; 492 int s; 493 494 s = splhigh(); 495 if (p->p_wchan) { 496 hp = &(qp = &slpque[LOOKUP(p->p_wchan)])->sq_head; 497 while (*hp != p) 498 hp = &(*hp)->p_forw; 499 *hp = p->p_forw; 500 if (qp->sq_tailp == &p->p_forw) 501 qp->sq_tailp = hp; 502 p->p_wchan = 0; 503 } 504 splx(s); 505 } 506 507 /* 508 * Make all processes sleeping on the specified identifier runnable. 509 */ 510 void 511 wakeup(ident) 512 register void *ident; 513 { 514 register struct slpque *qp; 515 register struct proc *p, **q; 516 int s; 517 518 s = splhigh(); 519 qp = &slpque[LOOKUP(ident)]; 520 restart: 521 for (q = &qp->sq_head; (p = *q) != NULL; ) { 522 #ifdef DIAGNOSTIC 523 if (p->p_back || (p->p_stat != SSLEEP && p->p_stat != SSTOP)) 524 panic("wakeup"); 525 #endif 526 if (p->p_wchan == ident) { 527 p->p_wchan = 0; 528 *q = p->p_forw; 529 if (qp->sq_tailp == &p->p_forw) 530 qp->sq_tailp = q; 531 if (p->p_stat == SSLEEP) { 532 /* OPTIMIZED EXPANSION OF setrunnable(p); */ 533 if (p->p_slptime > 1) 534 updatepri(p); 535 p->p_slptime = 0; 536 p->p_stat = SRUN; 537 if (p->p_flag & P_INMEM) 538 setrunqueue(p); 539 /* 540 * Since curpriority is a user priority, 541 * p->p_priority is always better than 542 * curpriority. 543 */ 544 if ((p->p_flag & P_INMEM) == 0) 545 wakeup((caddr_t)&proc0); 546 else 547 need_resched(); 548 /* END INLINE EXPANSION */ 549 goto restart; 550 } 551 } else 552 q = &p->p_forw; 553 } 554 splx(s); 555 } 556 557 /* 558 * The machine independent parts of mi_switch(). 559 * Must be called at splstatclock() or higher. 560 */ 561 void 562 mi_switch() 563 { 564 register struct proc *p = curproc; /* XXX */ 565 register struct rlimit *rlim; 566 register long s, u; 567 struct timeval tv; 568 569 /* 570 * Compute the amount of time during which the current 571 * process was running, and add that to its total so far. 572 */ 573 microtime(&tv); 574 u = p->p_rtime.tv_usec + (tv.tv_usec - runtime.tv_usec); 575 s = p->p_rtime.tv_sec + (tv.tv_sec - runtime.tv_sec); 576 if (u < 0) { 577 u += 1000000; 578 s--; 579 } else if (u >= 1000000) { 580 u -= 1000000; 581 s++; 582 } 583 p->p_rtime.tv_usec = u; 584 p->p_rtime.tv_sec = s; 585 586 /* 587 * Check if the process exceeds its cpu resource allocation. 588 * If over max, kill it. In any case, if it has run for more 589 * than 10 minutes, reduce priority to give others a chance. 590 */ 591 rlim = &p->p_rlimit[RLIMIT_CPU]; 592 if (s >= rlim->rlim_cur) { 593 if (s >= rlim->rlim_max) 594 psignal(p, SIGKILL); 595 else { 596 psignal(p, SIGXCPU); 597 if (rlim->rlim_cur < rlim->rlim_max) 598 rlim->rlim_cur += 5; 599 } 600 } 601 if (autonicetime && s > autonicetime && p->p_ucred->cr_uid && p->p_nice == NZERO) { 602 p->p_nice = autoniceval; 603 resetpriority(p); 604 } 605 606 /* 607 * Pick a new current process and record its start time. 608 */ 609 cnt.v_swtch++; 610 cpu_switch(p); 611 microtime(&runtime); 612 } 613 614 /* 615 * Initialize the (doubly-linked) run queues 616 * to be empty. 617 */ 618 void 619 rqinit() 620 { 621 register int i; 622 623 for (i = 0; i < NQS; i++) 624 qs[i].ph_link = qs[i].ph_rlink = (struct proc *)&qs[i]; 625 } 626 627 /* 628 * Change process state to be runnable, 629 * placing it on the run queue if it is in memory, 630 * and awakening the swapper if it isn't in memory. 631 */ 632 void 633 setrunnable(p) 634 register struct proc *p; 635 { 636 register int s; 637 638 s = splhigh(); 639 switch (p->p_stat) { 640 case 0: 641 case SRUN: 642 case SZOMB: 643 default: 644 panic("setrunnable"); 645 case SSTOP: 646 /* 647 * If we're being traced (possibly because someone attached us 648 * while we were stopped), check for a signal from the debugger. 649 */ 650 if ((p->p_flag & P_TRACED) != 0 && p->p_xstat != 0) 651 p->p_siglist |= sigmask(p->p_xstat); 652 case SSLEEP: 653 unsleep(p); /* e.g. when sending signals */ 654 break; 655 656 case SIDL: 657 break; 658 } 659 p->p_stat = SRUN; 660 if (p->p_flag & P_INMEM) 661 setrunqueue(p); 662 splx(s); 663 if (p->p_slptime > 1) 664 updatepri(p); 665 p->p_slptime = 0; 666 if ((p->p_flag & P_INMEM) == 0) 667 wakeup((caddr_t)&proc0); 668 else if (p->p_priority < curpriority) 669 need_resched(); 670 } 671 672 /* 673 * Compute the priority of a process when running in user mode. 674 * Arrange to reschedule if the resulting priority is better 675 * than that of the current process. 676 */ 677 void 678 resetpriority(p) 679 register struct proc *p; 680 { 681 register unsigned int newpriority; 682 683 newpriority = PUSER + p->p_estcpu / 4 + 2 * p->p_nice; 684 newpriority = min(newpriority, MAXPRI); 685 p->p_usrpri = newpriority; 686 if (newpriority < curpriority) 687 need_resched(); 688 } 689 690 #ifdef DDB 691 #include <machine/db_machdep.h> 692 693 #include <ddb/db_interface.h> 694 #include <ddb/db_output.h> 695 696 void 697 db_show_all_procs(addr, haddr, count, modif) 698 db_expr_t addr; 699 int haddr; 700 db_expr_t count; 701 char *modif; 702 { 703 int map = modif[0] == 'm'; 704 int doingzomb = 0; 705 struct proc *p, *pp; 706 707 p = allproc.lh_first; 708 db_printf(" pid proc addr %s comm wchan\n", 709 map ? "map " : "uid ppid pgrp flag stat em "); 710 while (p != 0) { 711 pp = p->p_pptr; 712 if (p->p_stat) { 713 db_printf("%5d %p %p ", 714 p->p_pid, p, p->p_addr); 715 if (map) 716 db_printf("%p %s ", 717 p->p_vmspace, p->p_comm); 718 else 719 db_printf("%3d %5d %5d %06x %d %s %s ", 720 p->p_cred->p_ruid, pp ? pp->p_pid : -1, 721 p->p_pgrp->pg_id, p->p_flag, p->p_stat, 722 p->p_emul->e_name, p->p_comm); 723 if (p->p_wchan) { 724 if (p->p_wmesg) 725 db_printf("%s ", p->p_wmesg); 726 db_printf("%p", p->p_wchan); 727 } 728 db_printf("\n"); 729 } 730 p = p->p_list.le_next; 731 if (p == 0 && doingzomb == 0) { 732 doingzomb = 1; 733 p = zombproc.lh_first; 734 } 735 } 736 } 737 #endif 738