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15637ed4 RG |
1 | /*- |
2 | * Copyright (c) 1982, 1986, 1990 The Regents of the University of California. | |
3 | * Copyright (c) 1991 The Regents of the University of California. | |
4 | * All rights reserved. | |
5 | * | |
6 | * Redistribution and use in source and binary forms, with or without | |
7 | * modification, are permitted provided that the following conditions | |
8 | * are met: | |
9 | * 1. Redistributions of source code must retain the above copyright | |
10 | * notice, this list of conditions and the following disclaimer. | |
11 | * 2. Redistributions in binary form must reproduce the above copyright | |
12 | * notice, this list of conditions and the following disclaimer in the | |
13 | * documentation and/or other materials provided with the distribution. | |
14 | * 3. All advertising materials mentioning features or use of this software | |
15 | * must display the following acknowledgement: | |
16 | * This product includes software developed by the University of | |
17 | * California, Berkeley and its contributors. | |
18 | * 4. Neither the name of the University nor the names of its contributors | |
19 | * may be used to endorse or promote products derived from this software | |
20 | * without specific prior written permission. | |
21 | * | |
22 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
23 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
24 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
25 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
26 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
27 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
28 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
29 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
30 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
31 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
32 | * SUCH DAMAGE. | |
33 | * | |
34 | * @(#)kern_synch.c 7.18 (Berkeley) 6/27/91 | |
35 | * | |
36 | * PATCHES MAGIC LEVEL PATCH THAT GOT US HERE | |
37 | * -------------------- ----- ---------------------- | |
38 | * CURRENT PATCH LEVEL: 1 00077 | |
39 | * -------------------- ----- ---------------------- | |
40 | * | |
41 | * 11 Dec 92 Williams Jolitz Fixed panic:remrq hangs | |
42 | */ | |
43 | ||
44 | #include "param.h" | |
45 | #include "systm.h" | |
46 | #include "proc.h" | |
47 | #include "kernel.h" | |
48 | #include "buf.h" | |
49 | #include "signalvar.h" | |
50 | #include "resourcevar.h" | |
51 | ||
52 | #include "machine/cpu.h" | |
53 | ||
54 | u_char curpri; /* usrpri of curproc */ | |
55 | ||
56 | /* | |
57 | * Force switch among equal priority processes every 100ms. | |
58 | */ | |
59 | roundrobin() | |
60 | { | |
61 | ||
62 | need_resched(); | |
63 | timeout(roundrobin, (caddr_t)0, hz / 10); | |
64 | } | |
65 | ||
66 | /* | |
67 | * constants for digital decay and forget | |
68 | * 90% of (p_cpu) usage in 5*loadav time | |
69 | * 95% of (p_pctcpu) usage in 60 seconds (load insensitive) | |
70 | * Note that, as ps(1) mentions, this can let percentages | |
71 | * total over 100% (I've seen 137.9% for 3 processes). | |
72 | * | |
73 | * Note that hardclock updates p_cpu and p_cpticks independently. | |
74 | * | |
75 | * We wish to decay away 90% of p_cpu in (5 * loadavg) seconds. | |
76 | * That is, the system wants to compute a value of decay such | |
77 | * that the following for loop: | |
78 | * for (i = 0; i < (5 * loadavg); i++) | |
79 | * p_cpu *= decay; | |
80 | * will compute | |
81 | * p_cpu *= 0.1; | |
82 | * for all values of loadavg: | |
83 | * | |
84 | * Mathematically this loop can be expressed by saying: | |
85 | * decay ** (5 * loadavg) ~= .1 | |
86 | * | |
87 | * The system computes decay as: | |
88 | * decay = (2 * loadavg) / (2 * loadavg + 1) | |
89 | * | |
90 | * We wish to prove that the system's computation of decay | |
91 | * will always fulfill the equation: | |
92 | * decay ** (5 * loadavg) ~= .1 | |
93 | * | |
94 | * If we compute b as: | |
95 | * b = 2 * loadavg | |
96 | * then | |
97 | * decay = b / (b + 1) | |
98 | * | |
99 | * We now need to prove two things: | |
100 | * 1) Given factor ** (5 * loadavg) ~= .1, prove factor == b/(b+1) | |
101 | * 2) Given b/(b+1) ** power ~= .1, prove power == (5 * loadavg) | |
102 | * | |
103 | * Facts: | |
104 | * For x close to zero, exp(x) =~ 1 + x, since | |
105 | * exp(x) = 0! + x**1/1! + x**2/2! + ... . | |
106 | * therefore exp(-1/b) =~ 1 - (1/b) = (b-1)/b. | |
107 | * For x close to zero, ln(1+x) =~ x, since | |
108 | * ln(1+x) = x - x**2/2 + x**3/3 - ... -1 < x < 1 | |
109 | * therefore ln(b/(b+1)) = ln(1 - 1/(b+1)) =~ -1/(b+1). | |
110 | * ln(.1) =~ -2.30 | |
111 | * | |
112 | * Proof of (1): | |
113 | * Solve (factor)**(power) =~ .1 given power (5*loadav): | |
114 | * solving for factor, | |
115 | * ln(factor) =~ (-2.30/5*loadav), or | |
116 | * factor =~ exp(-1/((5/2.30)*loadav)) =~ exp(-1/(2*loadav)) = | |
117 | * exp(-1/b) =~ (b-1)/b =~ b/(b+1). QED | |
118 | * | |
119 | * Proof of (2): | |
120 | * Solve (factor)**(power) =~ .1 given factor == (b/(b+1)): | |
121 | * solving for power, | |
122 | * power*ln(b/(b+1)) =~ -2.30, or | |
123 | * power =~ 2.3 * (b + 1) = 4.6*loadav + 2.3 =~ 5*loadav. QED | |
124 | * | |
125 | * Actual power values for the implemented algorithm are as follows: | |
126 | * loadav: 1 2 3 4 | |
127 | * power: 5.68 10.32 14.94 19.55 | |
128 | */ | |
129 | ||
130 | /* calculations for digital decay to forget 90% of usage in 5*loadav sec */ | |
131 | #define loadfactor(loadav) (2 * (loadav)) | |
132 | #define decay_cpu(loadfac, cpu) (((loadfac) * (cpu)) / ((loadfac) + FSCALE)) | |
133 | ||
134 | /* decay 95% of `p_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */ | |
135 | fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */ | |
136 | ||
137 | /* | |
138 | * If `ccpu' is not equal to `exp(-1/20)' and you still want to use the | |
139 | * faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below | |
140 | * and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT). | |
141 | * | |
142 | * To estimate CCPU_SHIFT for exp(-1/20), the following formula was used: | |
143 | * 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits). | |
144 | * | |
145 | * If you dont want to bother with the faster/more-accurate formula, you | |
146 | * can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate | |
147 | * (more general) method of calculating the %age of CPU used by a process. | |
148 | */ | |
149 | #define CCPU_SHIFT 11 | |
150 | ||
151 | /* | |
152 | * Recompute process priorities, once a second | |
153 | */ | |
154 | schedcpu() | |
155 | { | |
156 | register fixpt_t loadfac = loadfactor(averunnable[0]); | |
157 | register struct proc *p; | |
158 | register int s; | |
159 | register unsigned int newcpu; | |
160 | ||
161 | wakeup((caddr_t)&lbolt); | |
162 | for (p = allproc; p != NULL; p = p->p_nxt) { | |
163 | /* | |
164 | * Increment time in/out of memory and sleep time | |
165 | * (if sleeping). We ignore overflow; with 16-bit int's | |
166 | * (remember them?) overflow takes 45 days. | |
167 | */ | |
168 | p->p_time++; | |
169 | if (p->p_stat == SSLEEP || p->p_stat == SSTOP) | |
170 | p->p_slptime++; | |
171 | p->p_pctcpu = (p->p_pctcpu * ccpu) >> FSHIFT; | |
172 | /* | |
173 | * If the process has slept the entire second, | |
174 | * stop recalculating its priority until it wakes up. | |
175 | */ | |
176 | if (p->p_slptime > 1) | |
177 | continue; | |
178 | /* | |
179 | * p_pctcpu is only for ps. | |
180 | */ | |
181 | #if (FSHIFT >= CCPU_SHIFT) | |
182 | p->p_pctcpu += (hz == 100)? | |
183 | ((fixpt_t) p->p_cpticks) << (FSHIFT - CCPU_SHIFT): | |
184 | 100 * (((fixpt_t) p->p_cpticks) | |
185 | << (FSHIFT - CCPU_SHIFT)) / hz; | |
186 | #else | |
187 | p->p_pctcpu += ((FSCALE - ccpu) * | |
188 | (p->p_cpticks * FSCALE / hz)) >> FSHIFT; | |
189 | #endif | |
190 | p->p_cpticks = 0; | |
191 | newcpu = (u_int) decay_cpu(loadfac, p->p_cpu) + p->p_nice; | |
192 | p->p_cpu = min(newcpu, UCHAR_MAX); | |
193 | setpri(p); | |
194 | s = splhigh(); /* prevent state changes */ | |
195 | if (p->p_pri >= PUSER) { | |
196 | #define PPQ (128 / NQS) /* priorities per queue */ | |
197 | if ((p != curproc) && | |
198 | p->p_stat == SRUN && | |
199 | (p->p_flag & (SLOAD|SWEXIT)) == SLOAD && | |
200 | (p->p_pri / PPQ) != (p->p_usrpri / PPQ)) { | |
201 | remrq(p); | |
202 | p->p_pri = p->p_usrpri; | |
203 | setrq(p); | |
204 | } else | |
205 | p->p_pri = p->p_usrpri; | |
206 | } | |
207 | splx(s); | |
208 | } | |
209 | vmmeter(); | |
210 | if (bclnlist != NULL) | |
211 | wakeup((caddr_t)pageproc); | |
212 | timeout(schedcpu, (caddr_t)0, hz); | |
213 | } | |
214 | ||
215 | /* | |
216 | * Recalculate the priority of a process after it has slept for a while. | |
217 | * For all load averages >= 1 and max p_cpu of 255, sleeping for at least | |
218 | * six times the loadfactor will decay p_cpu to zero. | |
219 | */ | |
220 | updatepri(p) | |
221 | register struct proc *p; | |
222 | { | |
223 | register unsigned int newcpu = p->p_cpu; | |
224 | register fixpt_t loadfac = loadfactor(averunnable[0]); | |
225 | ||
226 | if (p->p_slptime > 5 * loadfac) | |
227 | p->p_cpu = 0; | |
228 | else { | |
229 | p->p_slptime--; /* the first time was done in schedcpu */ | |
230 | while (newcpu && --p->p_slptime) | |
231 | newcpu = (int) decay_cpu(loadfac, newcpu); | |
232 | p->p_cpu = min(newcpu, UCHAR_MAX); | |
233 | } | |
234 | setpri(p); | |
235 | } | |
236 | ||
237 | #define SQSIZE 0100 /* Must be power of 2 */ | |
238 | #define HASH(x) (( (int) x >> 5) & (SQSIZE-1)) | |
239 | struct slpque { | |
240 | struct proc *sq_head; | |
241 | struct proc **sq_tailp; | |
242 | } slpque[SQSIZE]; | |
243 | ||
244 | /* | |
245 | * During autoconfiguration or after a panic, a sleep will simply | |
246 | * lower the priority briefly to allow interrupts, then return. | |
247 | * The priority to be used (safepri) is machine-dependent, thus this | |
248 | * value is initialized and maintained in the machine-dependent layers. | |
249 | * This priority will typically be 0, or the lowest priority | |
250 | * that is safe for use on the interrupt stack; it can be made | |
251 | * higher to block network software interrupts after panics. | |
252 | */ | |
253 | int safepri; | |
254 | ||
255 | /* | |
256 | * General sleep call. | |
257 | * Suspends current process until a wakeup is made on chan. | |
258 | * The process will then be made runnable with priority pri. | |
259 | * Sleeps at most timo/hz seconds (0 means no timeout). | |
260 | * If pri includes PCATCH flag, signals are checked | |
261 | * before and after sleeping, else signals are not checked. | |
262 | * Returns 0 if awakened, EWOULDBLOCK if the timeout expires. | |
263 | * If PCATCH is set and a signal needs to be delivered, | |
264 | * ERESTART is returned if the current system call should be restarted | |
265 | * if possible, and EINTR is returned if the system call should | |
266 | * be interrupted by the signal (return EINTR). | |
267 | */ | |
268 | tsleep(chan, pri, wmesg, timo) | |
269 | caddr_t chan; | |
270 | int pri; | |
271 | char *wmesg; | |
272 | int timo; | |
273 | { | |
274 | register struct proc *p = curproc; | |
275 | register struct slpque *qp; | |
276 | register s; | |
277 | int sig, catch = pri & PCATCH; | |
278 | extern int cold; | |
279 | int endtsleep(); | |
280 | ||
281 | s = splhigh(); | |
282 | if (cold || panicstr) { | |
283 | /* | |
284 | * After a panic, or during autoconfiguration, | |
285 | * just give interrupts a chance, then just return; | |
286 | * don't run any other procs or panic below, | |
287 | * in case this is the idle process and already asleep. | |
288 | */ | |
289 | splx(safepri); | |
290 | splx(s); | |
291 | return (0); | |
292 | } | |
293 | #ifdef DIAGNOSTIC | |
294 | if (chan == 0 || p->p_stat != SRUN || p->p_rlink) | |
295 | panic("tsleep"); | |
296 | #endif | |
297 | p->p_wchan = chan; | |
298 | p->p_wmesg = wmesg; | |
299 | p->p_slptime = 0; | |
300 | p->p_pri = pri & PRIMASK; | |
301 | qp = &slpque[HASH(chan)]; | |
302 | if (qp->sq_head == 0) | |
303 | qp->sq_head = p; | |
304 | else | |
305 | *qp->sq_tailp = p; | |
306 | *(qp->sq_tailp = &p->p_link) = 0; | |
307 | if (timo) | |
308 | timeout(endtsleep, (caddr_t)p, timo); | |
309 | /* | |
310 | * We put ourselves on the sleep queue and start our timeout | |
311 | * before calling CURSIG, as we could stop there, and a wakeup | |
312 | * or a SIGCONT (or both) could occur while we were stopped. | |
313 | * A SIGCONT would cause us to be marked as SSLEEP | |
314 | * without resuming us, thus we must be ready for sleep | |
315 | * when CURSIG is called. If the wakeup happens while we're | |
316 | * stopped, p->p_wchan will be 0 upon return from CURSIG. | |
317 | */ | |
318 | if (catch) { | |
319 | p->p_flag |= SSINTR; | |
320 | if (sig = CURSIG(p)) { | |
321 | if (p->p_wchan) | |
322 | unsleep(p); | |
323 | p->p_stat = SRUN; | |
324 | goto resume; | |
325 | } | |
326 | if (p->p_wchan == 0) { | |
327 | catch = 0; | |
328 | goto resume; | |
329 | } | |
330 | } | |
331 | p->p_stat = SSLEEP; | |
332 | p->p_stats->p_ru.ru_nvcsw++; | |
333 | swtch(); | |
334 | #include "ddb.h" | |
335 | #ifdef NDDB | |
336 | /* handy breakpoint location after process "wakes" */ | |
337 | asm(".globl bpendtsleep ; bpendtsleep:"); | |
338 | #endif | |
339 | resume: | |
340 | curpri = p->p_usrpri; | |
341 | splx(s); | |
342 | p->p_flag &= ~SSINTR; | |
343 | if (p->p_flag & STIMO) { | |
344 | p->p_flag &= ~STIMO; | |
345 | if (catch == 0 || sig == 0) | |
346 | return (EWOULDBLOCK); | |
347 | } else if (timo) | |
348 | untimeout(endtsleep, (caddr_t)p); | |
349 | if (catch && (sig != 0 || (sig = CURSIG(p)))) { | |
350 | if (p->p_sigacts->ps_sigintr & sigmask(sig)) | |
351 | return (EINTR); | |
352 | return (ERESTART); | |
353 | } | |
354 | return (0); | |
355 | } | |
356 | ||
357 | /* | |
358 | * Implement timeout for tsleep. | |
359 | * If process hasn't been awakened (wchan non-zero), | |
360 | * set timeout flag and undo the sleep. If proc | |
361 | * is stopped, just unsleep so it will remain stopped. | |
362 | */ | |
363 | endtsleep(p) | |
364 | register struct proc *p; | |
365 | { | |
366 | int s = splhigh(); | |
367 | ||
368 | if (p->p_wchan) { | |
369 | if (p->p_stat == SSLEEP) | |
370 | setrun(p); | |
371 | else | |
372 | unsleep(p); | |
373 | p->p_flag |= STIMO; | |
374 | } | |
375 | splx(s); | |
376 | } | |
377 | ||
378 | /* | |
379 | * Short-term, non-interruptable sleep. | |
380 | */ | |
381 | sleep(chan, pri) | |
382 | caddr_t chan; | |
383 | int pri; | |
384 | { | |
385 | register struct proc *p = curproc; | |
386 | register struct slpque *qp; | |
387 | register s; | |
388 | extern int cold; | |
389 | ||
390 | #ifdef DIAGNOSTIC | |
391 | if (pri > PZERO) { | |
392 | printf("sleep called with pri %d > PZERO, wchan: %x\n", | |
393 | pri, chan); | |
394 | panic("old sleep"); | |
395 | } | |
396 | #endif | |
397 | s = splhigh(); | |
398 | if (cold || panicstr) { | |
399 | /* | |
400 | * After a panic, or during autoconfiguration, | |
401 | * just give interrupts a chance, then just return; | |
402 | * don't run any other procs or panic below, | |
403 | * in case this is the idle process and already asleep. | |
404 | */ | |
405 | splx(safepri); | |
406 | splx(s); | |
407 | return; | |
408 | } | |
409 | #ifdef DIAGNOSTIC | |
410 | if (chan==0 || p->p_stat != SRUN || p->p_rlink) | |
411 | panic("sleep"); | |
412 | #endif | |
413 | p->p_wchan = chan; | |
414 | p->p_wmesg = NULL; | |
415 | p->p_slptime = 0; | |
416 | p->p_pri = pri; | |
417 | qp = &slpque[HASH(chan)]; | |
418 | if (qp->sq_head == 0) | |
419 | qp->sq_head = p; | |
420 | else | |
421 | *qp->sq_tailp = p; | |
422 | *(qp->sq_tailp = &p->p_link) = 0; | |
423 | p->p_stat = SSLEEP; | |
424 | p->p_stats->p_ru.ru_nvcsw++; | |
425 | swtch(); | |
426 | #ifdef NDDB | |
427 | /* handy breakpoint location after process "wakes" */ | |
428 | asm(".globl bpendsleep ; bpendsleep:"); | |
429 | #endif | |
430 | curpri = p->p_usrpri; | |
431 | splx(s); | |
432 | } | |
433 | ||
434 | /* | |
435 | * Remove a process from its wait queue | |
436 | */ | |
437 | unsleep(p) | |
438 | register struct proc *p; | |
439 | { | |
440 | register struct slpque *qp; | |
441 | register struct proc **hp; | |
442 | int s; | |
443 | ||
444 | s = splhigh(); | |
445 | if (p->p_wchan) { | |
446 | hp = &(qp = &slpque[HASH(p->p_wchan)])->sq_head; | |
447 | while (*hp != p) | |
448 | hp = &(*hp)->p_link; | |
449 | *hp = p->p_link; | |
450 | if (qp->sq_tailp == &p->p_link) | |
451 | qp->sq_tailp = hp; | |
452 | p->p_wchan = 0; | |
453 | } | |
454 | splx(s); | |
455 | } | |
456 | ||
457 | /* | |
458 | * Wakeup on "chan"; set all processes | |
459 | * sleeping on chan to run state. | |
460 | */ | |
461 | wakeup(chan) | |
462 | register caddr_t chan; | |
463 | { | |
464 | register struct slpque *qp; | |
465 | register struct proc *p, **q; | |
466 | int s; | |
467 | ||
468 | s = splhigh(); | |
469 | qp = &slpque[HASH(chan)]; | |
470 | restart: | |
471 | for (q = &qp->sq_head; p = *q; ) { | |
472 | #ifdef DIAGNOSTIC | |
473 | if (p->p_rlink || p->p_stat != SSLEEP && p->p_stat != SSTOP) | |
474 | panic("wakeup"); | |
475 | #endif | |
476 | if (p->p_wchan == chan) { | |
477 | p->p_wchan = 0; | |
478 | *q = p->p_link; | |
479 | if (qp->sq_tailp == &p->p_link) | |
480 | qp->sq_tailp = q; | |
481 | if (p->p_stat == SSLEEP) { | |
482 | /* OPTIMIZED INLINE EXPANSION OF setrun(p) */ | |
483 | if (p->p_slptime > 1) | |
484 | updatepri(p); | |
485 | p->p_slptime = 0; | |
486 | p->p_stat = SRUN; | |
487 | if (p->p_flag & SLOAD) | |
488 | setrq(p); | |
489 | /* | |
490 | * Since curpri is a usrpri, | |
491 | * p->p_pri is always better than curpri. | |
492 | */ | |
493 | if ((p->p_flag&SLOAD) == 0) | |
494 | wakeup((caddr_t)&proc0); | |
495 | else | |
496 | need_resched(); | |
497 | /* END INLINE EXPANSION */ | |
498 | goto restart; | |
499 | } | |
500 | } else | |
501 | q = &p->p_link; | |
502 | } | |
503 | splx(s); | |
504 | } | |
505 | ||
506 | /* | |
507 | * Initialize the (doubly-linked) run queues | |
508 | * to be empty. | |
509 | */ | |
510 | rqinit() | |
511 | { | |
512 | register int i; | |
513 | ||
514 | for (i = 0; i < NQS; i++) | |
515 | qs[i].ph_link = qs[i].ph_rlink = (struct proc *)&qs[i]; | |
516 | } | |
517 | ||
518 | /* | |
519 | * Change process state to be runnable, | |
520 | * placing it on the run queue if it is in memory, | |
521 | * and awakening the swapper if it isn't in memory. | |
522 | */ | |
523 | setrun(p) | |
524 | register struct proc *p; | |
525 | { | |
526 | register int s; | |
527 | ||
528 | s = splhigh(); | |
529 | switch (p->p_stat) { | |
530 | ||
531 | case 0: | |
532 | case SWAIT: | |
533 | case SRUN: | |
534 | case SZOMB: | |
535 | default: | |
536 | panic("setrun"); | |
537 | ||
538 | case SSTOP: | |
539 | case SSLEEP: | |
540 | unsleep(p); /* e.g. when sending signals */ | |
541 | break; | |
542 | ||
543 | case SIDL: | |
544 | break; | |
545 | } | |
546 | p->p_stat = SRUN; | |
547 | if (p->p_flag & SLOAD) | |
548 | setrq(p); | |
549 | splx(s); | |
550 | if (p->p_slptime > 1) | |
551 | updatepri(p); | |
552 | p->p_slptime = 0; | |
553 | if ((p->p_flag&SLOAD) == 0) | |
554 | wakeup((caddr_t)&proc0); | |
555 | else if (p->p_pri < curpri) | |
556 | need_resched(); | |
557 | } | |
558 | ||
559 | /* | |
560 | * Compute priority of process when running in user mode. | |
561 | * Arrange to reschedule if the resulting priority | |
562 | * is better than that of the current process. | |
563 | */ | |
564 | setpri(p) | |
565 | register struct proc *p; | |
566 | { | |
567 | register unsigned int newpri; | |
568 | ||
569 | newpri = PUSER + p->p_cpu / 4 + 2 * p->p_nice; | |
570 | newpri = min(newpri, MAXPRI); | |
571 | p->p_usrpri = newpri; | |
572 | if (newpri < curpri) | |
573 | need_resched(); | |
574 | } | |
575 | ||
576 | #ifdef NDDB | |
577 | #define DDBFUNC(s) ddb_##s | |
578 | DDBFUNC(ps) () { | |
579 | int np; | |
580 | struct proc *ap, *p, *pp; | |
581 | np = nprocs; | |
582 | p = ap = allproc; | |
583 | printf(" pid proc addr uid ppid pgrp flag stat comm wchan\n"); | |
584 | while (--np >= 0) { | |
585 | pp = p->p_pptr; | |
586 | if (pp == 0) | |
587 | pp = p; | |
588 | if (p->p_stat) { | |
589 | printf("%5d %06x %06x %3d %5d %5d %06x %d %s ", | |
590 | p->p_pid, ap, p->p_addr, p->p_cred->p_ruid, pp->p_pid, | |
591 | p->p_pgrp->pg_id, p->p_flag, p->p_stat, | |
592 | p->p_comm); | |
593 | if (p->p_wchan) { | |
594 | if (p->p_wmesg) | |
595 | printf("%s ", p->p_wmesg); | |
596 | printf("%x", p->p_wchan); | |
597 | } | |
598 | printf("\n"); | |
599 | } | |
600 | ap = p->p_nxt; | |
601 | if (ap == 0 && np > 0) | |
602 | ap = zombproc; | |
603 | p = ap; | |
604 | } | |
605 | } | |
606 | #endif |