1/*-
2 * Copyright (c) 1982, 1986, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)subr_prof.c 8.3 (Berkeley) 9/23/93
| 1/*-
2 * Copyright (c) 1982, 1986, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)subr_prof.c 8.3 (Berkeley) 9/23/93
|
91#endif
92
93 /*
94 * Round lowpc and highpc to multiples of the density we're using
95 * so the rest of the scaling (here and in gprof) stays in ints.
96 */
97 p->lowpc = ROUNDDOWN((u_long)btext, HISTFRACTION * sizeof(HISTCOUNTER));
98 p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER));
99 p->textsize = p->highpc - p->lowpc;
100 printf("Profiling kernel, textsize=%lu [%x..%x]\n",
101 p->textsize, p->lowpc, p->highpc);
102 p->kcountsize = p->textsize / HISTFRACTION;
103 p->hashfraction = HASHFRACTION;
104 p->fromssize = p->textsize / HASHFRACTION;
105 p->tolimit = p->textsize * ARCDENSITY / 100;
106 if (p->tolimit < MINARCS)
107 p->tolimit = MINARCS;
108 else if (p->tolimit > MAXARCS)
109 p->tolimit = MAXARCS;
110 p->tossize = p->tolimit * sizeof(struct tostruct);
111 cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize,
112 M_GPROF, M_NOWAIT);
113 if (cp == 0) {
114 printf("No memory for profiling.\n");
115 return;
116 }
117 bzero(cp, p->kcountsize + p->tossize + p->fromssize);
118 p->tos = (struct tostruct *)cp;
119 cp += p->tossize;
120 p->kcount = (HISTCOUNTER *)cp;
121 cp += p->kcountsize;
122 p->froms = (u_short *)cp;
123
124#ifdef GUPROF
125 /* Initialize pointers to overhead counters. */
126 p->cputime_count = &KCOUNT(p, PC_TO_I(p, cputime));
127 p->mcount_count = &KCOUNT(p, PC_TO_I(p, mcount));
128 p->mexitcount_count = &KCOUNT(p, PC_TO_I(p, mexitcount));
129
130 /*
131 * Disable interrupts to avoid interference while we calibrate
132 * things.
133 */
134 disable_intr();
135
136 /*
137 * Determine overheads.
138 * XXX this needs to be repeated for each useful timer/counter.
139 */
140 cputime_overhead = 0;
141 startguprof(p);
142 for (i = 0; i < CALIB_SCALE; i++)
143 cputime_overhead += cputime();
144
145 empty_loop();
146 startguprof(p);
147 empty_loop();
148 empty_loop_time = cputime();
149
150 nullfunc_loop_profiled();
151
152 /*
153 * Start profiling. There won't be any normal function calls since
154 * interrupts are disabled, but we will call the profiling routines
155 * directly to determine their overheads.
156 */
157 p->state = GMON_PROF_HIRES;
158
159 startguprof(p);
160 nullfunc_loop_profiled();
161
162 startguprof(p);
163 for (i = 0; i < CALIB_SCALE; i++)
164#if defined(__i386__) && __GNUC__ >= 2
165 __asm("pushl %0; call __mcount; popl %%ecx"
166 :
167 : "i" (profil)
168 : "ax", "bx", "cx", "dx", "memory");
169#else
170#error
171#endif
172 mcount_overhead = KCOUNT(p, PC_TO_I(p, profil));
173
174 startguprof(p);
175 for (i = 0; i < CALIB_SCALE; i++)
176#if defined(__i386__) && __GNUC__ >= 2
177 __asm("call mexitcount; 1:"
178 : : : "ax", "bx", "cx", "dx", "memory");
179 __asm("movl $1b,%0" : "=rm" (tmp_addr));
180#else
181#error
182#endif
183 mexitcount_overhead = KCOUNT(p, PC_TO_I(p, tmp_addr));
184
185 p->state = GMON_PROF_OFF;
186 stopguprof(p);
187
188 enable_intr();
189
190 nullfunc_loop_profiled_time = 0;
| 91#endif
92
93 /*
94 * Round lowpc and highpc to multiples of the density we're using
95 * so the rest of the scaling (here and in gprof) stays in ints.
96 */
97 p->lowpc = ROUNDDOWN((u_long)btext, HISTFRACTION * sizeof(HISTCOUNTER));
98 p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER));
99 p->textsize = p->highpc - p->lowpc;
100 printf("Profiling kernel, textsize=%lu [%x..%x]\n",
101 p->textsize, p->lowpc, p->highpc);
102 p->kcountsize = p->textsize / HISTFRACTION;
103 p->hashfraction = HASHFRACTION;
104 p->fromssize = p->textsize / HASHFRACTION;
105 p->tolimit = p->textsize * ARCDENSITY / 100;
106 if (p->tolimit < MINARCS)
107 p->tolimit = MINARCS;
108 else if (p->tolimit > MAXARCS)
109 p->tolimit = MAXARCS;
110 p->tossize = p->tolimit * sizeof(struct tostruct);
111 cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize,
112 M_GPROF, M_NOWAIT);
113 if (cp == 0) {
114 printf("No memory for profiling.\n");
115 return;
116 }
117 bzero(cp, p->kcountsize + p->tossize + p->fromssize);
118 p->tos = (struct tostruct *)cp;
119 cp += p->tossize;
120 p->kcount = (HISTCOUNTER *)cp;
121 cp += p->kcountsize;
122 p->froms = (u_short *)cp;
123
124#ifdef GUPROF
125 /* Initialize pointers to overhead counters. */
126 p->cputime_count = &KCOUNT(p, PC_TO_I(p, cputime));
127 p->mcount_count = &KCOUNT(p, PC_TO_I(p, mcount));
128 p->mexitcount_count = &KCOUNT(p, PC_TO_I(p, mexitcount));
129
130 /*
131 * Disable interrupts to avoid interference while we calibrate
132 * things.
133 */
134 disable_intr();
135
136 /*
137 * Determine overheads.
138 * XXX this needs to be repeated for each useful timer/counter.
139 */
140 cputime_overhead = 0;
141 startguprof(p);
142 for (i = 0; i < CALIB_SCALE; i++)
143 cputime_overhead += cputime();
144
145 empty_loop();
146 startguprof(p);
147 empty_loop();
148 empty_loop_time = cputime();
149
150 nullfunc_loop_profiled();
151
152 /*
153 * Start profiling. There won't be any normal function calls since
154 * interrupts are disabled, but we will call the profiling routines
155 * directly to determine their overheads.
156 */
157 p->state = GMON_PROF_HIRES;
158
159 startguprof(p);
160 nullfunc_loop_profiled();
161
162 startguprof(p);
163 for (i = 0; i < CALIB_SCALE; i++)
164#if defined(__i386__) && __GNUC__ >= 2
165 __asm("pushl %0; call __mcount; popl %%ecx"
166 :
167 : "i" (profil)
168 : "ax", "bx", "cx", "dx", "memory");
169#else
170#error
171#endif
172 mcount_overhead = KCOUNT(p, PC_TO_I(p, profil));
173
174 startguprof(p);
175 for (i = 0; i < CALIB_SCALE; i++)
176#if defined(__i386__) && __GNUC__ >= 2
177 __asm("call mexitcount; 1:"
178 : : : "ax", "bx", "cx", "dx", "memory");
179 __asm("movl $1b,%0" : "=rm" (tmp_addr));
180#else
181#error
182#endif
183 mexitcount_overhead = KCOUNT(p, PC_TO_I(p, tmp_addr));
184
185 p->state = GMON_PROF_OFF;
186 stopguprof(p);
187
188 enable_intr();
189
190 nullfunc_loop_profiled_time = 0;
|
193 tmp_addr += HISTFRACTION * sizeof(HISTCOUNTER))
194 nullfunc_loop_profiled_time += KCOUNT(p, PC_TO_I(p, tmp_addr));
195#define CALIB_DOSCALE(count) (((count) + CALIB_SCALE / 3) / CALIB_SCALE)
196#define c2n(count, freq) ((int)((count) * 1000000000LL / freq))
197 printf("cputime %d, empty_loop %d, nullfunc_loop_profiled %d, mcount %d, mexitcount %d\n",
198 CALIB_DOSCALE(c2n(cputime_overhead, p->profrate)),
199 CALIB_DOSCALE(c2n(empty_loop_time, p->profrate)),
200 CALIB_DOSCALE(c2n(nullfunc_loop_profiled_time, p->profrate)),
201 CALIB_DOSCALE(c2n(mcount_overhead, p->profrate)),
202 CALIB_DOSCALE(c2n(mexitcount_overhead, p->profrate)));
203 cputime_overhead -= empty_loop_time;
204 mcount_overhead -= empty_loop_time;
205 mexitcount_overhead -= empty_loop_time;
206
207 /*-
208 * Profiling overheads are determined by the times between the
209 * following events:
210 * MC1: mcount() is called
211 * MC2: cputime() (called from mcount()) latches the timer
212 * MC3: mcount() completes
213 * ME1: mexitcount() is called
214 * ME2: cputime() (called from mexitcount()) latches the timer
215 * ME3: mexitcount() completes.
216 * The times between the events vary slightly depending on instruction
217 * combination and cache misses, etc. Attempt to determine the
218 * minimum times. These can be subtracted from the profiling times
219 * without much risk of reducing the profiling times below what they
220 * would be when profiling is not configured. Abbreviate:
221 * ab = minimum time between MC1 and MC3
222 * a = minumum time between MC1 and MC2
223 * b = minimum time between MC2 and MC3
224 * cd = minimum time between ME1 and ME3
225 * c = minimum time between ME1 and ME2
226 * d = minimum time between ME2 and ME3.
227 * These satisfy the relations:
228 * ab <= mcount_overhead (just measured)
229 * a + b <= ab
230 * cd <= mexitcount_overhead (just measured)
231 * c + d <= cd
232 * a + d <= nullfunc_loop_profiled_time (just measured)
233 * a >= 0, b >= 0, c >= 0, d >= 0.
234 * Assume that ab and cd are equal to the minimums.
235 */
236 p->cputime_overhead = CALIB_DOSCALE(cputime_overhead);
237 p->mcount_overhead = CALIB_DOSCALE(mcount_overhead - cputime_overhead);
238 p->mexitcount_overhead = CALIB_DOSCALE(mexitcount_overhead
239 - cputime_overhead);
240 nullfunc_loop_overhead = nullfunc_loop_profiled_time - empty_loop_time;
241 p->mexitcount_post_overhead = CALIB_DOSCALE((mcount_overhead
242 - nullfunc_loop_overhead)
243 / 4);
244 p->mexitcount_pre_overhead = p->mexitcount_overhead
245 + p->cputime_overhead
246 - p->mexitcount_post_overhead;
247 p->mcount_pre_overhead = CALIB_DOSCALE(nullfunc_loop_overhead)
248 - p->mexitcount_post_overhead;
249 p->mcount_post_overhead = p->mcount_overhead
250 + p->cputime_overhead
251 - p->mcount_pre_overhead;
252 printf(
253"Profiling overheads: mcount: %d+%d, %d+%d; mexitcount: %d+%d, %d+%d nsec\n",
254 c2n(p->cputime_overhead, p->profrate),
255 c2n(p->mcount_overhead, p->profrate),
256 c2n(p->mcount_pre_overhead, p->profrate),
257 c2n(p->mcount_post_overhead, p->profrate),
258 c2n(p->cputime_overhead, p->profrate),
259 c2n(p->mexitcount_overhead, p->profrate),
260 c2n(p->mexitcount_pre_overhead, p->profrate),
261 c2n(p->mexitcount_post_overhead, p->profrate));
262 printf(
263"Profiling overheads: mcount: %d+%d, %d+%d; mexitcount: %d+%d, %d+%d cycles\n",
264 p->cputime_overhead, p->mcount_overhead,
265 p->mcount_pre_overhead, p->mcount_post_overhead,
266 p->cputime_overhead, p->mexitcount_overhead,
267 p->mexitcount_pre_overhead, p->mexitcount_post_overhead);
268#endif /* GUPROF */
269}
270
271/*
272 * Return kernel profiling information.
273 */
274static int
275sysctl_kern_prof SYSCTL_HANDLER_ARGS
276{
277 int *name = (int *) arg1;
278 u_int namelen = arg2;
279 struct gmonparam *gp = &_gmonparam;
280 int error;
281 int state;
282
283 /* all sysctl names at this level are terminal */
284 if (namelen != 1)
285 return (ENOTDIR); /* overloaded */
286
287 switch (name[0]) {
288 case GPROF_STATE:
289 state = gp->state;
290 error = sysctl_handle_int(oidp, &state, 0, req);
291 if (error)
292 return (error);
293 if (!req->newptr)
294 return (0);
295 if (state == GMON_PROF_OFF) {
296 gp->state = state;
297 stopprofclock(&proc0);
298 stopguprof(gp);
299 } else if (state == GMON_PROF_ON) {
300 gp->state = GMON_PROF_OFF;
301 stopguprof(gp);
302 gp->profrate = profhz;
303 startprofclock(&proc0);
304 gp->state = state;
305#ifdef GUPROF
306 } else if (state == GMON_PROF_HIRES) {
307 gp->state = GMON_PROF_OFF;
308 stopprofclock(&proc0);
309 startguprof(gp);
310 gp->state = state;
311#endif
312 } else if (state != gp->state)
313 return (EINVAL);
314 return (0);
315 case GPROF_COUNT:
316 return (sysctl_handle_opaque(oidp,
317 gp->kcount, gp->kcountsize, req));
318 case GPROF_FROMS:
319 return (sysctl_handle_opaque(oidp,
320 gp->froms, gp->fromssize, req));
321 case GPROF_TOS:
322 return (sysctl_handle_opaque(oidp,
323 gp->tos, gp->tossize, req));
324 case GPROF_GMONPARAM:
325 return (sysctl_handle_opaque(oidp, gp, sizeof *gp, req));
326 default:
327 return (EOPNOTSUPP);
328 }
329 /* NOTREACHED */
330}
331
332SYSCTL_NODE(_kern, KERN_PROF, prof, CTLFLAG_RW, sysctl_kern_prof, "");
333#endif /* GPROF */
334
335/*
336 * Profiling system call.
337 *
338 * The scale factor is a fixed point number with 16 bits of fraction, so that
339 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling.
340 */
341#ifndef _SYS_SYSPROTO_H_
342struct profil_args {
343 caddr_t samples;
344 u_int size;
345 u_int offset;
346 u_int scale;
347};
348#endif
349/* ARGSUSED */
350int
351profil(p, uap)
352 struct proc *p;
353 register struct profil_args *uap;
354{
355 register struct uprof *upp;
356 int s;
357
358 if (uap->scale > (1 << 16))
359 return (EINVAL);
360 if (uap->scale == 0) {
361 stopprofclock(p);
362 return (0);
363 }
364 upp = &p->p_stats->p_prof;
365
366 /* Block profile interrupts while changing state. */
367 s = splstatclock();
368 upp->pr_off = uap->offset;
369 upp->pr_scale = uap->scale;
370 upp->pr_base = uap->samples;
371 upp->pr_size = uap->size;
372 startprofclock(p);
373 splx(s);
374
375 return (0);
376}
377
378/*
379 * Scale is a fixed-point number with the binary point 16 bits
380 * into the value, and is <= 1.0. pc is at most 32 bits, so the
381 * intermediate result is at most 48 bits.
382 */
383#define PC_TO_INDEX(pc, prof) \
384 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \
385 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1)
386
387/*
388 * Collect user-level profiling statistics; called on a profiling tick,
389 * when a process is running in user-mode. This routine may be called
390 * from an interrupt context. We try to update the user profiling buffers
391 * cheaply with fuswintr() and suswintr(). If that fails, we revert to
392 * an AST that will vector us to trap() with a context in which copyin
393 * and copyout will work. Trap will then call addupc_task().
394 *
395 * Note that we may (rarely) not get around to the AST soon enough, and
396 * lose profile ticks when the next tick overwrites this one, but in this
397 * case the system is overloaded and the profile is probably already
398 * inaccurate.
399 */
400void
401addupc_intr(p, pc, ticks)
402 register struct proc *p;
403 register u_long pc;
404 u_int ticks;
405{
406 register struct uprof *prof;
407 register caddr_t addr;
408 register u_int i;
409 register int v;
410
411 if (ticks == 0)
412 return;
413 prof = &p->p_stats->p_prof;
414 if (pc < prof->pr_off ||
415 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size)
416 return; /* out of range; ignore */
417
418 addr = prof->pr_base + i;
419 if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + ticks) == -1) {
420 prof->pr_addr = pc;
421 prof->pr_ticks = ticks;
422 need_proftick(p);
423 }
424}
425
426/*
427 * Much like before, but we can afford to take faults here. If the
428 * update fails, we simply turn off profiling.
429 */
430void
431addupc_task(p, pc, ticks)
432 register struct proc *p;
433 register u_long pc;
434 u_int ticks;
435{
436 register struct uprof *prof;
437 register caddr_t addr;
438 register u_int i;
439 u_short v;
440
441 /* Testing P_PROFIL may be unnecessary, but is certainly safe. */
442 if ((p->p_flag & P_PROFIL) == 0 || ticks == 0)
443 return;
444
445 prof = &p->p_stats->p_prof;
446 if (pc < prof->pr_off ||
447 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size)
448 return;
449
450 addr = prof->pr_base + i;
451 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) {
452 v += ticks;
453 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0)
454 return;
455 }
456 stopprofclock(p);
457}
| 193 tmp_addr += HISTFRACTION * sizeof(HISTCOUNTER))
194 nullfunc_loop_profiled_time += KCOUNT(p, PC_TO_I(p, tmp_addr));
195#define CALIB_DOSCALE(count) (((count) + CALIB_SCALE / 3) / CALIB_SCALE)
196#define c2n(count, freq) ((int)((count) * 1000000000LL / freq))
197 printf("cputime %d, empty_loop %d, nullfunc_loop_profiled %d, mcount %d, mexitcount %d\n",
198 CALIB_DOSCALE(c2n(cputime_overhead, p->profrate)),
199 CALIB_DOSCALE(c2n(empty_loop_time, p->profrate)),
200 CALIB_DOSCALE(c2n(nullfunc_loop_profiled_time, p->profrate)),
201 CALIB_DOSCALE(c2n(mcount_overhead, p->profrate)),
202 CALIB_DOSCALE(c2n(mexitcount_overhead, p->profrate)));
203 cputime_overhead -= empty_loop_time;
204 mcount_overhead -= empty_loop_time;
205 mexitcount_overhead -= empty_loop_time;
206
207 /*-
208 * Profiling overheads are determined by the times between the
209 * following events:
210 * MC1: mcount() is called
211 * MC2: cputime() (called from mcount()) latches the timer
212 * MC3: mcount() completes
213 * ME1: mexitcount() is called
214 * ME2: cputime() (called from mexitcount()) latches the timer
215 * ME3: mexitcount() completes.
216 * The times between the events vary slightly depending on instruction
217 * combination and cache misses, etc. Attempt to determine the
218 * minimum times. These can be subtracted from the profiling times
219 * without much risk of reducing the profiling times below what they
220 * would be when profiling is not configured. Abbreviate:
221 * ab = minimum time between MC1 and MC3
222 * a = minumum time between MC1 and MC2
223 * b = minimum time between MC2 and MC3
224 * cd = minimum time between ME1 and ME3
225 * c = minimum time between ME1 and ME2
226 * d = minimum time between ME2 and ME3.
227 * These satisfy the relations:
228 * ab <= mcount_overhead (just measured)
229 * a + b <= ab
230 * cd <= mexitcount_overhead (just measured)
231 * c + d <= cd
232 * a + d <= nullfunc_loop_profiled_time (just measured)
233 * a >= 0, b >= 0, c >= 0, d >= 0.
234 * Assume that ab and cd are equal to the minimums.
235 */
236 p->cputime_overhead = CALIB_DOSCALE(cputime_overhead);
237 p->mcount_overhead = CALIB_DOSCALE(mcount_overhead - cputime_overhead);
238 p->mexitcount_overhead = CALIB_DOSCALE(mexitcount_overhead
239 - cputime_overhead);
240 nullfunc_loop_overhead = nullfunc_loop_profiled_time - empty_loop_time;
241 p->mexitcount_post_overhead = CALIB_DOSCALE((mcount_overhead
242 - nullfunc_loop_overhead)
243 / 4);
244 p->mexitcount_pre_overhead = p->mexitcount_overhead
245 + p->cputime_overhead
246 - p->mexitcount_post_overhead;
247 p->mcount_pre_overhead = CALIB_DOSCALE(nullfunc_loop_overhead)
248 - p->mexitcount_post_overhead;
249 p->mcount_post_overhead = p->mcount_overhead
250 + p->cputime_overhead
251 - p->mcount_pre_overhead;
252 printf(
253"Profiling overheads: mcount: %d+%d, %d+%d; mexitcount: %d+%d, %d+%d nsec\n",
254 c2n(p->cputime_overhead, p->profrate),
255 c2n(p->mcount_overhead, p->profrate),
256 c2n(p->mcount_pre_overhead, p->profrate),
257 c2n(p->mcount_post_overhead, p->profrate),
258 c2n(p->cputime_overhead, p->profrate),
259 c2n(p->mexitcount_overhead, p->profrate),
260 c2n(p->mexitcount_pre_overhead, p->profrate),
261 c2n(p->mexitcount_post_overhead, p->profrate));
262 printf(
263"Profiling overheads: mcount: %d+%d, %d+%d; mexitcount: %d+%d, %d+%d cycles\n",
264 p->cputime_overhead, p->mcount_overhead,
265 p->mcount_pre_overhead, p->mcount_post_overhead,
266 p->cputime_overhead, p->mexitcount_overhead,
267 p->mexitcount_pre_overhead, p->mexitcount_post_overhead);
268#endif /* GUPROF */
269}
270
271/*
272 * Return kernel profiling information.
273 */
274static int
275sysctl_kern_prof SYSCTL_HANDLER_ARGS
276{
277 int *name = (int *) arg1;
278 u_int namelen = arg2;
279 struct gmonparam *gp = &_gmonparam;
280 int error;
281 int state;
282
283 /* all sysctl names at this level are terminal */
284 if (namelen != 1)
285 return (ENOTDIR); /* overloaded */
286
287 switch (name[0]) {
288 case GPROF_STATE:
289 state = gp->state;
290 error = sysctl_handle_int(oidp, &state, 0, req);
291 if (error)
292 return (error);
293 if (!req->newptr)
294 return (0);
295 if (state == GMON_PROF_OFF) {
296 gp->state = state;
297 stopprofclock(&proc0);
298 stopguprof(gp);
299 } else if (state == GMON_PROF_ON) {
300 gp->state = GMON_PROF_OFF;
301 stopguprof(gp);
302 gp->profrate = profhz;
303 startprofclock(&proc0);
304 gp->state = state;
305#ifdef GUPROF
306 } else if (state == GMON_PROF_HIRES) {
307 gp->state = GMON_PROF_OFF;
308 stopprofclock(&proc0);
309 startguprof(gp);
310 gp->state = state;
311#endif
312 } else if (state != gp->state)
313 return (EINVAL);
314 return (0);
315 case GPROF_COUNT:
316 return (sysctl_handle_opaque(oidp,
317 gp->kcount, gp->kcountsize, req));
318 case GPROF_FROMS:
319 return (sysctl_handle_opaque(oidp,
320 gp->froms, gp->fromssize, req));
321 case GPROF_TOS:
322 return (sysctl_handle_opaque(oidp,
323 gp->tos, gp->tossize, req));
324 case GPROF_GMONPARAM:
325 return (sysctl_handle_opaque(oidp, gp, sizeof *gp, req));
326 default:
327 return (EOPNOTSUPP);
328 }
329 /* NOTREACHED */
330}
331
332SYSCTL_NODE(_kern, KERN_PROF, prof, CTLFLAG_RW, sysctl_kern_prof, "");
333#endif /* GPROF */
334
335/*
336 * Profiling system call.
337 *
338 * The scale factor is a fixed point number with 16 bits of fraction, so that
339 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling.
340 */
341#ifndef _SYS_SYSPROTO_H_
342struct profil_args {
343 caddr_t samples;
344 u_int size;
345 u_int offset;
346 u_int scale;
347};
348#endif
349/* ARGSUSED */
350int
351profil(p, uap)
352 struct proc *p;
353 register struct profil_args *uap;
354{
355 register struct uprof *upp;
356 int s;
357
358 if (uap->scale > (1 << 16))
359 return (EINVAL);
360 if (uap->scale == 0) {
361 stopprofclock(p);
362 return (0);
363 }
364 upp = &p->p_stats->p_prof;
365
366 /* Block profile interrupts while changing state. */
367 s = splstatclock();
368 upp->pr_off = uap->offset;
369 upp->pr_scale = uap->scale;
370 upp->pr_base = uap->samples;
371 upp->pr_size = uap->size;
372 startprofclock(p);
373 splx(s);
374
375 return (0);
376}
377
378/*
379 * Scale is a fixed-point number with the binary point 16 bits
380 * into the value, and is <= 1.0. pc is at most 32 bits, so the
381 * intermediate result is at most 48 bits.
382 */
383#define PC_TO_INDEX(pc, prof) \
384 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \
385 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1)
386
387/*
388 * Collect user-level profiling statistics; called on a profiling tick,
389 * when a process is running in user-mode. This routine may be called
390 * from an interrupt context. We try to update the user profiling buffers
391 * cheaply with fuswintr() and suswintr(). If that fails, we revert to
392 * an AST that will vector us to trap() with a context in which copyin
393 * and copyout will work. Trap will then call addupc_task().
394 *
395 * Note that we may (rarely) not get around to the AST soon enough, and
396 * lose profile ticks when the next tick overwrites this one, but in this
397 * case the system is overloaded and the profile is probably already
398 * inaccurate.
399 */
400void
401addupc_intr(p, pc, ticks)
402 register struct proc *p;
403 register u_long pc;
404 u_int ticks;
405{
406 register struct uprof *prof;
407 register caddr_t addr;
408 register u_int i;
409 register int v;
410
411 if (ticks == 0)
412 return;
413 prof = &p->p_stats->p_prof;
414 if (pc < prof->pr_off ||
415 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size)
416 return; /* out of range; ignore */
417
418 addr = prof->pr_base + i;
419 if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + ticks) == -1) {
420 prof->pr_addr = pc;
421 prof->pr_ticks = ticks;
422 need_proftick(p);
423 }
424}
425
426/*
427 * Much like before, but we can afford to take faults here. If the
428 * update fails, we simply turn off profiling.
429 */
430void
431addupc_task(p, pc, ticks)
432 register struct proc *p;
433 register u_long pc;
434 u_int ticks;
435{
436 register struct uprof *prof;
437 register caddr_t addr;
438 register u_int i;
439 u_short v;
440
441 /* Testing P_PROFIL may be unnecessary, but is certainly safe. */
442 if ((p->p_flag & P_PROFIL) == 0 || ticks == 0)
443 return;
444
445 prof = &p->p_stats->p_prof;
446 if (pc < prof->pr_off ||
447 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size)
448 return;
449
450 addr = prof->pr_base + i;
451 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) {
452 v += ticks;
453 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0)
454 return;
455 }
456 stopprofclock(p);
457}
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