Commit | Line | Data |
---|---|---|
e4d539fa | 1 | /* vm_meter.c 4.18 83/01/08 */ |
e3bf9f41 BJ |
2 | |
3 | #include "../h/param.h" | |
4 | #include "../h/systm.h" | |
5 | #include "../h/seg.h" | |
6 | #include "../h/dir.h" | |
7 | #include "../h/user.h" | |
8 | #include "../h/proc.h" | |
9 | #include "../h/text.h" | |
10 | #include "../h/vm.h" | |
11 | #include "../h/cmap.h" | |
c4206698 | 12 | #include "../h/kernel.h" |
e3bf9f41 | 13 | |
e3bf9f41 | 14 | int maxslp = MAXSLP; |
e3bf9f41 | 15 | int saferss = SAFERSS; |
27b135c8 BJ |
16 | |
17 | /* | |
18 | * The following parameters control operation of the page replacement | |
19 | * algorithm. They are initialized to 0, and then computed at boot time | |
20 | * based on the size of the system. If they are patched non-zero in | |
21 | * a loaded vmunix they are left alone and may thus be changed per system | |
22 | * using adb on the loaded system. | |
23 | */ | |
24 | int maxpgio = 0; | |
25 | int minfree = 0; | |
26 | int desfree = 0; | |
27 | int lotsfree = 0; | |
28 | int slowscan = 0; | |
29 | int fastscan = 0; | |
e3bf9f41 | 30 | int klin = KLIN; |
27b135c8 | 31 | int klseql = KLSEQL; |
4643e8eb | 32 | int klsdist = KLSDIST; |
27b135c8 | 33 | int kltxt = KLTXT; |
e3bf9f41 BJ |
34 | int klout = KLOUT; |
35 | int multprog = -1; /* so we don't count process 2 */ | |
36 | ||
37 | double avenrun[3]; /* load average, of runnable procs */ | |
38 | ||
27b135c8 BJ |
39 | /* |
40 | * Setup the paging constants for the clock algorithm. | |
41 | * Called after the system is initialized and the amount of memory | |
42 | * and number of paging devices is known. | |
43 | */ | |
44 | setupclock() | |
45 | { | |
27b135c8 BJ |
46 | |
47 | /* | |
48 | * Setup thresholds for paging: | |
49 | * lotsfree is threshold where paging daemon turns on | |
50 | * desfree is amount of memory desired free. if less | |
51 | * than this for extended period, do swapping | |
52 | * minfree is minimal amount of free memory which is | |
53 | * tolerable. | |
54 | * | |
55 | * Strategy of 4/22/81: | |
56 | * lotsfree is 1/4 of memory free. | |
57 | * desfree is 200k bytes, but at most 1/8 of memory | |
37324218 | 58 | * minfree is 64k bytes, but at most 1/2 of desfree |
27b135c8 BJ |
59 | */ |
60 | if (lotsfree == 0) | |
61 | lotsfree = LOOPPAGES / 4; | |
62 | if (desfree == 0) { | |
63 | desfree = (200*1024) / NBPG; | |
64 | if (desfree > LOOPPAGES / 8) | |
65 | desfree = LOOPPAGES / 8; | |
66 | } | |
37324218 BJ |
67 | if (minfree == 0) { |
68 | minfree = (64*1024) / NBPG; | |
69 | if (minfree > desfree/2) | |
70 | minfree = desfree / 2; | |
71 | } | |
27b135c8 BJ |
72 | |
73 | /* | |
74 | * Maxpgio thresholds how much paging is acceptable. | |
75 | * This figures that 2/3 busy on an arm is all that is | |
76 | * tolerable for paging. We assume one operation per disk rev. | |
77 | */ | |
78 | if (maxpgio == 0) | |
79 | maxpgio = (DISKRPM * 2) / 3; | |
80 | ||
81 | /* | |
55908f17 BJ |
82 | * Clock to scan using max of ~~10% of processor time for sampling, |
83 | * this estimated to allow maximum of 200 samples per second. | |
abc92597 | 84 | * This yields a ``fastscan'' of roughly (with CLSIZE=2): |
55908f17 BJ |
85 | * <=1m 2m 3m 4m 8m |
86 | * 5s 10s 15s 20s 40s | |
27b135c8 | 87 | */ |
abc92597 BJ |
88 | if (nswdev == 1 && physmem*NBPG > 2*1024*(1024-16)) |
89 | printf("WARNING: should run interleaved swap with >= 2Mb\n"); | |
90 | if (fastscan == 0) | |
55908f17 | 91 | fastscan = (LOOPPAGES/CLSIZE) / 200; |
abc92597 BJ |
92 | if (fastscan < 5) |
93 | fastscan = 5; | |
898c2303 | 94 | if (nswdev >= 2) |
abc92597 | 95 | maxpgio = (maxpgio * 3) / 2; |
27b135c8 BJ |
96 | |
97 | /* | |
55908f17 | 98 | * Set slow scan time to 1/2 the fast scan time. |
27b135c8 BJ |
99 | */ |
100 | if (slowscan == 0) | |
55908f17 | 101 | slowscan = 2 * fastscan; |
ebc86953 | 102 | #ifdef notdef |
27b135c8 BJ |
103 | printf("slowscan %d, fastscan %d, maxpgio %d\n", |
104 | slowscan, fastscan, maxpgio); | |
105 | printf("lotsfree %d, desfree %d, minfree %d\n", | |
106 | lotsfree, desfree, minfree); | |
107 | #endif | |
108 | } | |
109 | ||
e3bf9f41 BJ |
110 | /* |
111 | * The main loop of the scheduling (swapping) process. | |
112 | * | |
113 | * The basic idea is: | |
114 | * see if anyone wants to be swapped in; | |
115 | * swap out processes until there is room; | |
116 | * swap him in; | |
117 | * repeat. | |
118 | * If the paging rate is too high, or the average free memory | |
119 | * is very low, then we do not consider swapping anyone in, | |
120 | * but rather look for someone to swap out. | |
121 | * | |
122 | * The runout flag is set whenever someone is swapped out. | |
123 | * Sched sleeps on it awaiting work. | |
124 | * | |
125 | * Sched sleeps on runin whenever it cannot find enough | |
126 | * core (by swapping out or otherwise) to fit the | |
127 | * selected swapped process. It is awakened when the | |
128 | * core situation changes and in any case once per second. | |
129 | * | |
130 | * sched DOESN'T ACCOUNT FOR PAGE TABLE SIZE IN CALCULATIONS. | |
131 | */ | |
132 | ||
133 | #define swappable(p) \ | |
134 | (((p)->p_flag&(SSYS|SLOCK|SULOCK|SLOAD|SPAGE|SKEEP|SWEXIT|SPHYSIO))==SLOAD) | |
135 | ||
136 | /* insure non-zero */ | |
137 | #define nz(x) (x != 0 ? x : 1) | |
138 | ||
139 | #define NBIG 4 | |
140 | #define MAXNBIG 10 | |
141 | int nbig = NBIG; | |
142 | ||
143 | struct bigp { | |
144 | struct proc *bp_proc; | |
145 | int bp_pri; | |
146 | struct bigp *bp_link; | |
147 | } bigp[MAXNBIG], bplist; | |
148 | ||
149 | sched() | |
150 | { | |
151 | register struct proc *rp, *p, *inp; | |
152 | int outpri, inpri, rppri; | |
97afa637 | 153 | int sleeper, desperate, deservin, needs, divisor; |
e3bf9f41 BJ |
154 | register struct bigp *bp, *nbp; |
155 | int biggot, gives; | |
156 | ||
e3bf9f41 | 157 | loop: |
7eb2e67e | 158 | wantin = 0; |
e3bf9f41 BJ |
159 | deservin = 0; |
160 | sleeper = 0; | |
161 | p = 0; | |
27b135c8 | 162 | /* |
37324218 | 163 | * See if paging system is overloaded; if so swap someone out. |
27b135c8 BJ |
164 | * Conditions for hard outswap are: |
165 | * if need kernel map (mix it up). | |
166 | * or | |
167 | * 1. if there are at least 2 runnable processes (on the average) | |
168 | * and 2. the paging rate is excessive or memory is now VERY low. | |
169 | * and 3. the short (5-second) and longer (30-second) average | |
170 | * memory is less than desirable. | |
171 | */ | |
7328c465 BJ |
172 | if ( |
173 | #ifdef NOPAGING | |
174 | freemem == 0 || | |
175 | #endif | |
176 | kmapwnt || (avenrun[0] >= 2 && imax(avefree, avefree30) < desfree && | |
e3bf9f41 | 177 | (rate.v_pgin + rate.v_pgout > maxpgio || avefree < minfree))) { |
97afa637 | 178 | desperate = 1; |
e3bf9f41 BJ |
179 | goto hardswap; |
180 | } | |
97afa637 | 181 | desperate = 0; |
e3bf9f41 | 182 | /* |
97afa637 | 183 | * Not desperate for core, |
e3bf9f41 BJ |
184 | * look for someone who deserves to be brought in. |
185 | */ | |
186 | outpri = -20000; | |
86fd527f | 187 | for (rp = proc; rp < procNPROC; rp++) switch(rp->p_stat) { |
e3bf9f41 BJ |
188 | |
189 | case SRUN: | |
190 | if ((rp->p_flag&SLOAD) == 0) { | |
27b135c8 BJ |
191 | rppri = rp->p_time - |
192 | rp->p_swrss / nz((maxpgio/2) * (klin * CLSIZE)) + | |
293c7069 | 193 | rp->p_slptime - (rp->p_nice-NZERO)*8; |
e3bf9f41 BJ |
194 | if (rppri > outpri) { |
195 | if (rp->p_poip) | |
196 | continue; | |
197 | if (rp->p_textp && rp->p_textp->x_poip) | |
198 | continue; | |
199 | p = rp; | |
200 | outpri = rppri; | |
201 | } | |
202 | } | |
203 | continue; | |
204 | ||
205 | case SSLEEP: | |
206 | case SSTOP: | |
207 | if ((freemem < desfree || rp->p_rssize == 0) && | |
208 | rp->p_slptime > maxslp && | |
209 | (!rp->p_textp || (rp->p_textp->x_flag&XLOCK)==0) && | |
210 | swappable(rp)) { | |
211 | /* | |
212 | * Kick out deadwood. | |
e3bf9f41 | 213 | */ |
7eb2e67e | 214 | (void) spl6(); |
e3bf9f41 BJ |
215 | rp->p_flag &= ~SLOAD; |
216 | if (rp->p_stat == SRUN) | |
217 | remrq(rp); | |
7eb2e67e | 218 | (void) spl0(); |
e650efcf | 219 | (void) swapout(rp, rp->p_dsize, rp->p_ssize); |
e3bf9f41 BJ |
220 | goto loop; |
221 | } | |
222 | continue; | |
223 | } | |
224 | ||
225 | /* | |
226 | * No one wants in, so nothing to do. | |
227 | */ | |
228 | if (outpri == -20000) { | |
7eb2e67e BJ |
229 | (void) spl6(); |
230 | if (wantin) { | |
231 | wantin = 0; | |
232 | sleep((caddr_t)&lbolt, PSWP); | |
233 | } else { | |
234 | runout++; | |
235 | sleep((caddr_t)&runout, PSWP); | |
236 | } | |
237 | (void) spl0(); | |
e3bf9f41 BJ |
238 | goto loop; |
239 | } | |
e3bf9f41 BJ |
240 | /* |
241 | * Decide how deserving this guy is. If he is deserving | |
242 | * we will be willing to work harder to bring him in. | |
243 | * Needs is an estimate of how much core he will need. | |
244 | * If he has been out for a while, then we will | |
245 | * bring him in with 1/2 the core he will need, otherwise | |
246 | * we are conservative. | |
247 | */ | |
248 | deservin = 0; | |
249 | divisor = 1; | |
250 | if (outpri > maxslp/2) { | |
251 | deservin = 1; | |
7328c465 BJ |
252 | #ifdef NOPAGING |
253 | divisor = 1; | |
254 | #else | |
e3bf9f41 | 255 | divisor = 2; |
7328c465 | 256 | #endif |
e3bf9f41 BJ |
257 | } |
258 | needs = p->p_swrss; | |
259 | if (p->p_textp && p->p_textp->x_ccount == 0) | |
260 | needs += p->p_textp->x_swrss; | |
27b135c8 | 261 | needs = imin(needs, lotsfree); |
e3bf9f41 BJ |
262 | if (freemem - deficit > needs / divisor) { |
263 | deficit += needs; | |
264 | if (swapin(p)) | |
265 | goto loop; | |
266 | deficit -= imin(needs, deficit); | |
267 | } | |
268 | ||
269 | hardswap: | |
270 | /* | |
271 | * Need resources (kernel map or memory), swap someone out. | |
272 | * Select the nbig largest jobs, then the oldest of these | |
273 | * is ``most likely to get booted.'' | |
274 | */ | |
e3bf9f41 BJ |
275 | inp = p; |
276 | sleeper = 0; | |
277 | if (nbig > MAXNBIG) | |
278 | nbig = MAXNBIG; | |
279 | if (nbig < 1) | |
280 | nbig = 1; | |
281 | biggot = 0; | |
282 | bplist.bp_link = 0; | |
86fd527f | 283 | for (rp = proc; rp < procNPROC; rp++) { |
e3bf9f41 BJ |
284 | if (!swappable(rp)) |
285 | continue; | |
286 | if (rp->p_stat==SZOMB) | |
287 | continue; | |
288 | if (rp == inp) | |
289 | continue; | |
290 | if (rp->p_textp && rp->p_textp->x_flag&XLOCK) | |
291 | continue; | |
292 | if (rp->p_slptime > maxslp && | |
89b899a0 | 293 | (rp->p_stat==SSLEEP&&rp->p_pri>PZERO||rp->p_stat==SSTOP)) { |
e3bf9f41 BJ |
294 | if (sleeper < rp->p_slptime) { |
295 | p = rp; | |
296 | sleeper = rp->p_slptime; | |
297 | } | |
298 | } else if (!sleeper && (rp->p_stat==SRUN||rp->p_stat==SSLEEP)) { | |
299 | rppri = rp->p_rssize; | |
300 | if (rp->p_textp) | |
293c7069 | 301 | rppri += rp->p_textp->x_rssize/rp->p_textp->x_ccount; |
e3bf9f41 BJ |
302 | if (biggot < nbig) |
303 | nbp = &bigp[biggot++]; | |
304 | else { | |
305 | nbp = bplist.bp_link; | |
306 | if (nbp->bp_pri > rppri) | |
307 | continue; | |
308 | bplist.bp_link = nbp->bp_link; | |
309 | } | |
310 | for (bp = &bplist; bp->bp_link; bp = bp->bp_link) | |
311 | if (rppri < bp->bp_link->bp_pri) | |
312 | break; | |
313 | nbp->bp_link = bp->bp_link; | |
314 | bp->bp_link = nbp; | |
315 | nbp->bp_pri = rppri; | |
316 | nbp->bp_proc = rp; | |
317 | } | |
318 | } | |
319 | if (!sleeper) { | |
320 | p = NULL; | |
321 | inpri = -1000; | |
322 | for (bp = bplist.bp_link; bp; bp = bp->bp_link) { | |
323 | rp = bp->bp_proc; | |
324 | rppri = rp->p_time+rp->p_nice-NZERO; | |
325 | if (rppri >= inpri) { | |
326 | p = rp; | |
327 | inpri = rppri; | |
328 | } | |
329 | } | |
330 | } | |
331 | /* | |
97afa637 | 332 | * If we found a long-time sleeper, or we are desperate and |
e3bf9f41 BJ |
333 | * found anyone to swap out, or if someone deserves to come |
334 | * in and we didn't find a sleeper, but found someone who | |
335 | * has been in core for a reasonable length of time, then | |
336 | * we kick the poor luser out. | |
337 | */ | |
97afa637 | 338 | if (sleeper || desperate && p || deservin && inpri > maxslp) { |
7eb2e67e | 339 | (void) spl6(); |
e3bf9f41 BJ |
340 | p->p_flag &= ~SLOAD; |
341 | if (p->p_stat == SRUN) | |
342 | remrq(p); | |
7eb2e67e | 343 | (void) spl0(); |
97afa637 | 344 | if (desperate) { |
e3bf9f41 BJ |
345 | /* |
346 | * Want to give this space to the rest of | |
347 | * the processes in core so give them a chance | |
348 | * by increasing the deficit. | |
349 | */ | |
350 | gives = p->p_rssize; | |
351 | if (p->p_textp) | |
352 | gives += p->p_textp->x_rssize / p->p_textp->x_ccount; | |
9eec1cb0 | 353 | gives = imin(gives, lotsfree); |
e3bf9f41 BJ |
354 | deficit += gives; |
355 | } else | |
356 | gives = 0; /* someone else taketh away */ | |
357 | if (swapout(p, p->p_dsize, p->p_ssize) == 0) | |
358 | deficit -= imin(gives, deficit); | |
359 | goto loop; | |
360 | } | |
361 | /* | |
362 | * Want to swap someone in, but can't | |
363 | * so wait on runin. | |
364 | */ | |
e650efcf | 365 | (void) spl6(); |
e3bf9f41 BJ |
366 | runin++; |
367 | sleep((caddr_t)&runin, PSWP); | |
7eb2e67e | 368 | (void) spl0(); |
e3bf9f41 BJ |
369 | goto loop; |
370 | } | |
371 | ||
372 | vmmeter() | |
373 | { | |
374 | register unsigned *cp, *rp, *sp; | |
375 | ||
27b135c8 BJ |
376 | deficit -= imin(deficit, |
377 | imax(deficit / 10, ((klin * CLSIZE) / 2) * maxpgio / 2)); | |
e3bf9f41 | 378 | ave(avefree, freemem, 5); |
27b135c8 | 379 | ave(avefree30, freemem, 30); |
e3bf9f41 BJ |
380 | /* v_pgin is maintained by clock.c */ |
381 | cp = &cnt.v_first; rp = &rate.v_first; sp = &sum.v_first; | |
382 | while (cp <= &cnt.v_last) { | |
383 | ave(*rp, *cp, 5); | |
384 | *sp += *cp; | |
385 | *cp = 0; | |
386 | rp++, cp++, sp++; | |
387 | } | |
c4206698 | 388 | if (time.tv_sec % 5 == 0) { |
e3bf9f41 BJ |
389 | vmtotal(); |
390 | rate.v_swpin = cnt.v_swpin; | |
391 | sum.v_swpin += cnt.v_swpin; | |
392 | cnt.v_swpin = 0; | |
393 | rate.v_swpout = cnt.v_swpout; | |
394 | sum.v_swpout += cnt.v_swpout; | |
395 | cnt.v_swpout = 0; | |
396 | } | |
397 | if (avefree < minfree && runout || proc[0].p_slptime > maxslp/2) { | |
398 | runout = 0; | |
399 | runin = 0; | |
400 | wakeup((caddr_t)&runin); | |
401 | wakeup((caddr_t)&runout); | |
402 | } | |
403 | } | |
404 | ||
c4206698 BJ |
405 | #define RATETOSCHEDPAGING 4 /* hz that is */ |
406 | ||
407 | /* | |
408 | * Schedule rate for paging. | |
409 | * Rate is linear interpolation between | |
410 | * slowscan with lotsfree and fastscan when out of memory. | |
411 | */ | |
412 | schedpaging() | |
e3bf9f41 | 413 | { |
c4206698 | 414 | register int vavail, scanrate; |
e3bf9f41 | 415 | |
e3bf9f41 BJ |
416 | nscan = desscan = 0; |
417 | vavail = freemem - deficit; | |
418 | if (vavail < 0) | |
419 | vavail = 0; | |
e4d539fa SL |
420 | if (freemem < lotsfree) { |
421 | scanrate = | |
422 | (slowscan * vavail + fastscan * (lotsfree - vavail)) / | |
423 | nz(lotsfree); | |
424 | desscan = ((LOOPPAGES / CLSIZE) / nz(scanrate)) / | |
425 | RATETOSCHEDPAGING; | |
426 | wakeup((caddr_t)&proc[2]); | |
427 | } | |
b32450f4 | 428 | timeout(schedpaging, (caddr_t)0, hz / RATETOSCHEDPAGING); |
e3bf9f41 BJ |
429 | } |
430 | ||
431 | vmtotal() | |
432 | { | |
433 | register struct proc *p; | |
434 | register struct text *xp; | |
435 | int nrun = 0; | |
436 | ||
437 | total.t_vmtxt = 0; | |
438 | total.t_avmtxt = 0; | |
439 | total.t_rmtxt = 0; | |
440 | total.t_armtxt = 0; | |
fcb2d36b | 441 | for (xp = text; xp < textNTEXT; xp++) |
e3bf9f41 BJ |
442 | if (xp->x_iptr) { |
443 | total.t_vmtxt += xp->x_size; | |
444 | total.t_rmtxt += xp->x_rssize; | |
445 | for (p = xp->x_caddr; p; p = p->p_xlink) | |
446 | switch (p->p_stat) { | |
447 | ||
448 | case SSTOP: | |
449 | case SSLEEP: | |
450 | if (p->p_slptime >= maxslp) | |
451 | continue; | |
452 | /* fall into... */ | |
453 | ||
454 | case SRUN: | |
455 | case SIDL: | |
456 | total.t_avmtxt += xp->x_size; | |
457 | total.t_armtxt += xp->x_rssize; | |
458 | goto next; | |
459 | } | |
460 | next: | |
461 | ; | |
462 | } | |
463 | total.t_vm = 0; | |
464 | total.t_avm = 0; | |
465 | total.t_rm = 0; | |
466 | total.t_arm = 0; | |
467 | total.t_rq = 0; | |
468 | total.t_dw = 0; | |
469 | total.t_pw = 0; | |
470 | total.t_sl = 0; | |
471 | total.t_sw = 0; | |
86fd527f | 472 | for (p = proc; p < procNPROC; p++) { |
e3bf9f41 BJ |
473 | if (p->p_flag & SSYS) |
474 | continue; | |
475 | if (p->p_stat) { | |
476 | total.t_vm += p->p_dsize + p->p_ssize; | |
477 | total.t_rm += p->p_rssize; | |
478 | switch (p->p_stat) { | |
479 | ||
480 | case SSLEEP: | |
481 | case SSTOP: | |
89b899a0 | 482 | if (p->p_pri <= PZERO) |
e3bf9f41 BJ |
483 | nrun++; |
484 | if (p->p_flag & SPAGE) | |
485 | total.t_pw++; | |
486 | else if (p->p_flag & SLOAD) { | |
89b899a0 | 487 | if (p->p_pri <= PZERO) |
e3bf9f41 BJ |
488 | total.t_dw++; |
489 | else if (p->p_slptime < maxslp) | |
490 | total.t_sl++; | |
491 | } else if (p->p_slptime < maxslp) | |
492 | total.t_sw++; | |
493 | if (p->p_slptime < maxslp) | |
494 | goto active; | |
495 | break; | |
496 | ||
497 | case SRUN: | |
498 | case SIDL: | |
499 | nrun++; | |
500 | if (p->p_flag & SLOAD) | |
501 | total.t_rq++; | |
502 | else | |
503 | total.t_sw++; | |
504 | active: | |
505 | total.t_avm += p->p_dsize + p->p_ssize; | |
506 | total.t_arm += p->p_rssize; | |
507 | break; | |
508 | } | |
509 | } | |
510 | } | |
511 | total.t_vm += total.t_vmtxt; | |
512 | total.t_avm += total.t_avmtxt; | |
513 | total.t_rm += total.t_rmtxt; | |
514 | total.t_arm += total.t_armtxt; | |
515 | total.t_free = avefree; | |
516 | loadav(avenrun, nrun); | |
517 | } | |
518 | ||
519 | /* | |
520 | * Constants for averages over 1, 5, and 15 minutes | |
521 | * when sampling at 5 second intervals. | |
522 | */ | |
523 | double cexp[3] = { | |
524 | 0.9200444146293232, /* exp(-1/12) */ | |
525 | 0.9834714538216174, /* exp(-1/60) */ | |
526 | 0.9944598480048967, /* exp(-1/180) */ | |
527 | }; | |
528 | ||
529 | /* | |
530 | * Compute a tenex style load average of a quantity on | |
531 | * 1, 5 and 15 minute intervals. | |
532 | */ | |
533 | loadav(avg, n) | |
534 | register double *avg; | |
535 | int n; | |
536 | { | |
537 | register int i; | |
538 | ||
539 | for (i = 0; i < 3; i++) | |
540 | avg[i] = cexp[i] * avg[i] + n * (1.0 - cexp[i]); | |
541 | } |