Commit | Line | Data |
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1d348849 | 1 | /* kern_synch.c 6.2 84/05/22 */ |
961945a8 SL |
2 | |
3 | #include "../machine/pte.h" | |
a379cce8 BJ |
4 | |
5 | #include "../h/param.h" | |
6 | #include "../h/systm.h" | |
7 | #include "../h/dir.h" | |
8 | #include "../h/user.h" | |
9 | #include "../h/proc.h" | |
10 | #include "../h/file.h" | |
11 | #include "../h/inode.h" | |
12 | #include "../h/vm.h" | |
1edb1cf8 BJ |
13 | #include "../h/kernel.h" |
14 | #include "../h/buf.h" | |
15 | ||
961945a8 SL |
16 | #ifdef vax |
17 | #include "../vax/mtpr.h" /* XXX */ | |
18 | #endif | |
1edb1cf8 BJ |
19 | /* |
20 | * Force switch among equal priority processes every 100ms. | |
21 | */ | |
22 | roundrobin() | |
23 | { | |
24 | ||
25 | runrun++; | |
26 | aston(); | |
b32450f4 | 27 | timeout(roundrobin, (caddr_t)0, hz / 10); |
1edb1cf8 BJ |
28 | } |
29 | ||
d01b68d6 | 30 | /* constants to digital decay and forget 90% of usage in 5*loadav time */ |
1edb1cf8 BJ |
31 | #undef ave |
32 | #define ave(a,b) ((int)(((int)(a*b))/(b+1))) | |
33 | int nrscale = 2; | |
1edb1cf8 BJ |
34 | double ccpu = 0.95122942450071400909; /* exp(-1/20) */ |
35 | ||
1edb1cf8 BJ |
36 | /* |
37 | * Recompute process priorities, once a second | |
38 | */ | |
39 | schedcpu() | |
40 | { | |
41 | register struct proc *p; | |
42 | register int s, a; | |
43 | ||
1edb1cf8 | 44 | wakeup((caddr_t)&lbolt); |
1d348849 | 45 | for (p = allproc; p != NULL; p = p->p_nxt) { |
1edb1cf8 BJ |
46 | if (p->p_time != 127) |
47 | p->p_time++; | |
1edb1cf8 BJ |
48 | if (p->p_stat==SSLEEP || p->p_stat==SSTOP) |
49 | if (p->p_slptime != 127) | |
50 | p->p_slptime++; | |
51 | if (p->p_flag&SLOAD) | |
52 | p->p_pctcpu = ccpu * p->p_pctcpu + | |
53 | (1.0 - ccpu) * (p->p_cpticks/(float)hz); | |
54 | p->p_cpticks = 0; | |
1edb1cf8 BJ |
55 | a = ave((p->p_cpu & 0377), avenrun[0]*nrscale) + |
56 | p->p_nice - NZERO; | |
1edb1cf8 BJ |
57 | if (a < 0) |
58 | a = 0; | |
59 | if (a > 255) | |
60 | a = 255; | |
61 | p->p_cpu = a; | |
62 | (void) setpri(p); | |
63 | s = spl6(); /* prevent state changes */ | |
64 | if (p->p_pri >= PUSER) { | |
65 | if ((p != u.u_procp || noproc) && | |
66 | p->p_stat == SRUN && | |
67 | (p->p_flag & SLOAD) && | |
68 | p->p_pri != p->p_usrpri) { | |
69 | remrq(p); | |
70 | p->p_pri = p->p_usrpri; | |
71 | setrq(p); | |
72 | } else | |
73 | p->p_pri = p->p_usrpri; | |
74 | } | |
75 | splx(s); | |
76 | } | |
77 | vmmeter(); | |
78 | if (runin!=0) { | |
79 | runin = 0; | |
80 | wakeup((caddr_t)&runin); | |
81 | } | |
82 | if (bclnlist != NULL) | |
83 | wakeup((caddr_t)&proc[2]); | |
b32450f4 | 84 | timeout(schedcpu, (caddr_t)0, hz); |
1edb1cf8 | 85 | } |
a379cce8 BJ |
86 | |
87 | #define SQSIZE 0100 /* Must be power of 2 */ | |
88 | #define HASH(x) (( (int) x >> 5) & (SQSIZE-1)) | |
89 | struct proc *slpque[SQSIZE]; | |
90 | ||
91 | /* | |
92 | * Give up the processor till a wakeup occurs | |
93 | * on chan, at which time the process | |
94 | * enters the scheduling queue at priority pri. | |
95 | * The most important effect of pri is that when | |
96 | * pri<=PZERO a signal cannot disturb the sleep; | |
97 | * if pri>PZERO signals will be processed. | |
98 | * Callers of this routine must be prepared for | |
99 | * premature return, and check that the reason for | |
100 | * sleeping has gone away. | |
101 | */ | |
102 | sleep(chan, pri) | |
bd76c595 BJ |
103 | caddr_t chan; |
104 | int pri; | |
a379cce8 | 105 | { |
e5df4be8 | 106 | register struct proc *rp, **hp; |
6fdc0335 | 107 | register s; |
a379cce8 BJ |
108 | |
109 | rp = u.u_procp; | |
110 | s = spl6(); | |
111 | if (chan==0 || rp->p_stat != SRUN || rp->p_rlink) | |
112 | panic("sleep"); | |
a379cce8 BJ |
113 | rp->p_wchan = chan; |
114 | rp->p_slptime = 0; | |
115 | rp->p_pri = pri; | |
e5df4be8 BJ |
116 | hp = &slpque[HASH(chan)]; |
117 | rp->p_link = *hp; | |
118 | *hp = rp; | |
18a4549b BJ |
119 | if (pri > PZERO) { |
120 | if (ISSIG(rp)) { | |
e5df4be8 BJ |
121 | if (rp->p_wchan) |
122 | unsleep(rp); | |
a379cce8 | 123 | rp->p_stat = SRUN; |
81263dba | 124 | (void) spl0(); |
a379cce8 BJ |
125 | goto psig; |
126 | } | |
e5df4be8 BJ |
127 | if (rp->p_wchan == 0) |
128 | goto out; | |
129 | rp->p_stat = SSLEEP; | |
81263dba | 130 | (void) spl0(); |
bd76c595 | 131 | u.u_ru.ru_nvcsw++; |
a379cce8 | 132 | swtch(); |
18a4549b | 133 | if (ISSIG(rp)) |
a379cce8 BJ |
134 | goto psig; |
135 | } else { | |
6fdc0335 | 136 | rp->p_stat = SSLEEP; |
81263dba | 137 | (void) spl0(); |
bd76c595 | 138 | u.u_ru.ru_nvcsw++; |
a379cce8 BJ |
139 | swtch(); |
140 | } | |
e5df4be8 | 141 | out: |
a379cce8 BJ |
142 | splx(s); |
143 | return; | |
144 | ||
145 | /* | |
146 | * If priority was low (>PZERO) and | |
18a4549b | 147 | * there has been a signal, execute non-local goto through |
d01b68d6 | 148 | * u.u_qsave, aborting the system call in progress (see trap.c) |
18a4549b | 149 | * (or finishing a tsleep, see below) |
a379cce8 BJ |
150 | */ |
151 | psig: | |
d01b68d6 | 152 | longjmp(&u.u_qsave); |
a379cce8 BJ |
153 | /*NOTREACHED*/ |
154 | } | |
155 | ||
87d0f32e BJ |
156 | /* |
157 | * Remove a process from its wait queue | |
158 | */ | |
159 | unsleep(p) | |
18a4549b | 160 | register struct proc *p; |
87d0f32e BJ |
161 | { |
162 | register struct proc **hp; | |
163 | register s; | |
164 | ||
165 | s = spl6(); | |
166 | if (p->p_wchan) { | |
167 | hp = &slpque[HASH(p->p_wchan)]; | |
168 | while (*hp != p) | |
169 | hp = &(*hp)->p_link; | |
170 | *hp = p->p_link; | |
171 | p->p_wchan = 0; | |
172 | } | |
173 | splx(s); | |
174 | } | |
175 | ||
a379cce8 BJ |
176 | /* |
177 | * Wake up all processes sleeping on chan. | |
178 | */ | |
179 | wakeup(chan) | |
18a4549b | 180 | register caddr_t chan; |
a379cce8 | 181 | { |
e5df4be8 | 182 | register struct proc *p, **q, **h; |
a379cce8 BJ |
183 | int s; |
184 | ||
185 | s = spl6(); | |
e5df4be8 | 186 | h = &slpque[HASH(chan)]; |
a379cce8 | 187 | restart: |
e5df4be8 | 188 | for (q = h; p = *q; ) { |
87d0f32e | 189 | if (p->p_rlink || p->p_stat != SSLEEP && p->p_stat != SSTOP) |
a379cce8 | 190 | panic("wakeup"); |
6fdc0335 | 191 | if (p->p_wchan==chan) { |
a379cce8 | 192 | p->p_wchan = 0; |
e5df4be8 | 193 | *q = p->p_link; |
a379cce8 | 194 | p->p_slptime = 0; |
87d0f32e BJ |
195 | if (p->p_stat == SSLEEP) { |
196 | /* OPTIMIZED INLINE EXPANSION OF setrun(p) */ | |
197 | p->p_stat = SRUN; | |
c74c8a79 | 198 | if (p->p_flag & SLOAD) |
87d0f32e | 199 | setrq(p); |
18a4549b | 200 | if (p->p_pri < curpri) { |
87d0f32e | 201 | runrun++; |
534d9295 BJ |
202 | aston(); |
203 | } | |
7eb2e67e BJ |
204 | if ((p->p_flag&SLOAD) == 0) { |
205 | if (runout != 0) { | |
206 | runout = 0; | |
207 | wakeup((caddr_t)&runout); | |
208 | } | |
209 | wantin++; | |
87d0f32e BJ |
210 | } |
211 | /* END INLINE EXPANSION */ | |
e5df4be8 | 212 | goto restart; |
a379cce8 | 213 | } |
e5df4be8 BJ |
214 | } else |
215 | q = &p->p_link; | |
a379cce8 BJ |
216 | } |
217 | splx(s); | |
218 | } | |
219 | ||
a379cce8 BJ |
220 | /* |
221 | * Initialize the (doubly-linked) run queues | |
222 | * to be empty. | |
223 | */ | |
224 | rqinit() | |
225 | { | |
226 | register int i; | |
227 | ||
228 | for (i = 0; i < NQS; i++) | |
229 | qs[i].ph_link = qs[i].ph_rlink = (struct proc *)&qs[i]; | |
230 | } | |
a379cce8 BJ |
231 | |
232 | /* | |
233 | * Set the process running; | |
234 | * arrange for it to be swapped in if necessary. | |
235 | */ | |
236 | setrun(p) | |
18a4549b | 237 | register struct proc *p; |
a379cce8 | 238 | { |
18a4549b | 239 | register int s; |
a379cce8 BJ |
240 | |
241 | s = spl6(); | |
242 | switch (p->p_stat) { | |
243 | ||
244 | case 0: | |
245 | case SWAIT: | |
246 | case SRUN: | |
247 | case SZOMB: | |
248 | default: | |
249 | panic("setrun"); | |
250 | ||
6fdc0335 | 251 | case SSTOP: |
a379cce8 | 252 | case SSLEEP: |
87d0f32e | 253 | unsleep(p); /* e.g. when sending signals */ |
a379cce8 BJ |
254 | break; |
255 | ||
256 | case SIDL: | |
a379cce8 BJ |
257 | break; |
258 | } | |
259 | p->p_stat = SRUN; | |
260 | if (p->p_flag & SLOAD) | |
261 | setrq(p); | |
262 | splx(s); | |
18a4549b | 263 | if (p->p_pri < curpri) { |
a379cce8 | 264 | runrun++; |
534d9295 BJ |
265 | aston(); |
266 | } | |
7eb2e67e | 267 | if ((p->p_flag&SLOAD) == 0) { |
18a4549b | 268 | if (runout != 0) { |
7eb2e67e BJ |
269 | runout = 0; |
270 | wakeup((caddr_t)&runout); | |
271 | } | |
272 | wantin++; | |
a379cce8 BJ |
273 | } |
274 | } | |
275 | ||
276 | /* | |
277 | * Set user priority. | |
278 | * The rescheduling flag (runrun) | |
279 | * is set if the priority is better | |
280 | * than the currently running process. | |
281 | */ | |
282 | setpri(pp) | |
18a4549b | 283 | register struct proc *pp; |
a379cce8 | 284 | { |
18a4549b | 285 | register int p; |
a379cce8 | 286 | |
16a64baa | 287 | p = (pp->p_cpu & 0377)/4; |
598563b5 | 288 | p += PUSER + 2*(pp->p_nice - NZERO); |
9afea775 BJ |
289 | if (pp->p_rssize > pp->p_maxrss && freemem < desfree) |
290 | p += 2*4; /* effectively, nice(4) */ | |
18a4549b | 291 | if (p > 127) |
a379cce8 | 292 | p = 127; |
18a4549b | 293 | if (p < curpri) { |
a379cce8 | 294 | runrun++; |
a51a6e74 BJ |
295 | aston(); |
296 | } | |
a379cce8 | 297 | pp->p_usrpri = p; |
18a4549b | 298 | return (p); |
a379cce8 | 299 | } |