Rename printf -> kprintf in sys/ and add some defines where necessary
[dragonfly.git] / sys / kern / subr_prof.c
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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
34 * $FreeBSD: src/sys/kern/subr_prof.c,v 1.32.2.2 2000/08/03 00:09:32 ps Exp $
6ea70f76 35 * $DragonFly: src/sys/kern/subr_prof.c,v 1.14 2006/12/23 00:35:04 swildner Exp $
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36 */
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/sysproto.h>
41#include <sys/kernel.h>
42#include <sys/proc.h>
43#include <sys/resourcevar.h>
44#include <sys/sysctl.h>
e43a034f 45#include <sys/thread2.h>
984263bc 46
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47#include <machine/cpu.h>
48
49#ifdef GPROF
50#include <sys/malloc.h>
51#include <sys/gmon.h>
52#undef MCOUNT
53
54static MALLOC_DEFINE(M_GPROF, "gprof", "kernel profiling buffer");
55
402ed7e1 56static void kmstartup (void *);
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57SYSINIT(kmem, SI_SUB_KPROF, SI_ORDER_FIRST, kmstartup, NULL)
58
59struct gmonparam _gmonparam = { GMON_PROF_OFF };
60
61#ifdef GUPROF
62#include <machine/asmacros.h>
63
64void
65nullfunc_loop_profiled()
66{
67 int i;
68
69 for (i = 0; i < CALIB_SCALE; i++)
70 nullfunc_profiled();
71}
72
73#define nullfunc_loop_profiled_end nullfunc_profiled /* XXX */
74
75void
76nullfunc_profiled()
77{
78}
79#endif /* GUPROF */
80
81static void
493c516a 82kmstartup(void *dummy)
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83{
84 char *cp;
85 struct gmonparam *p = &_gmonparam;
86#ifdef GUPROF
87 int cputime_overhead;
88 int empty_loop_time;
89 int i;
90 int mcount_overhead;
91 int mexitcount_overhead;
92 int nullfunc_loop_overhead;
93 int nullfunc_loop_profiled_time;
94 uintfptr_t tmp_addr;
95#endif
96
97 /*
98 * Round lowpc and highpc to multiples of the density we're using
99 * so the rest of the scaling (here and in gprof) stays in ints.
100 */
101 p->lowpc = ROUNDDOWN((u_long)btext, HISTFRACTION * sizeof(HISTCOUNTER));
102 p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER));
103 p->textsize = p->highpc - p->lowpc;
6ea70f76 104 kprintf("Profiling kernel, textsize=%lu [%x..%x]\n",
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105 p->textsize, p->lowpc, p->highpc);
106 p->kcountsize = p->textsize / HISTFRACTION;
107 p->hashfraction = HASHFRACTION;
108 p->fromssize = p->textsize / HASHFRACTION;
109 p->tolimit = p->textsize * ARCDENSITY / 100;
110 if (p->tolimit < MINARCS)
111 p->tolimit = MINARCS;
112 else if (p->tolimit > MAXARCS)
113 p->tolimit = MAXARCS;
114 p->tossize = p->tolimit * sizeof(struct tostruct);
115 cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize,
116 M_GPROF, M_NOWAIT);
117 if (cp == 0) {
6ea70f76 118 kprintf("No memory for profiling.\n");
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119 return;
120 }
121 bzero(cp, p->kcountsize + p->tossize + p->fromssize);
122 p->tos = (struct tostruct *)cp;
123 cp += p->tossize;
124 p->kcount = (HISTCOUNTER *)cp;
125 cp += p->kcountsize;
126 p->froms = (u_short *)cp;
127
128#ifdef GUPROF
129 /* Initialize pointers to overhead counters. */
130 p->cputime_count = &KCOUNT(p, PC_TO_I(p, cputime));
131 p->mcount_count = &KCOUNT(p, PC_TO_I(p, mcount));
132 p->mexitcount_count = &KCOUNT(p, PC_TO_I(p, mexitcount));
133
134 /*
135 * Disable interrupts to avoid interference while we calibrate
136 * things.
137 */
eac48440 138 cpu_disable_intr();
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139
140 /*
141 * Determine overheads.
142 * XXX this needs to be repeated for each useful timer/counter.
143 */
144 cputime_overhead = 0;
145 startguprof(p);
146 for (i = 0; i < CALIB_SCALE; i++)
147 cputime_overhead += cputime();
148
149 empty_loop();
150 startguprof(p);
151 empty_loop();
152 empty_loop_time = cputime();
153
154 nullfunc_loop_profiled();
155
156 /*
157 * Start profiling. There won't be any normal function calls since
158 * interrupts are disabled, but we will call the profiling routines
159 * directly to determine their overheads.
160 */
161 p->state = GMON_PROF_HIRES;
162
163 startguprof(p);
164 nullfunc_loop_profiled();
165
166 startguprof(p);
167 for (i = 0; i < CALIB_SCALE; i++)
168#if defined(__i386__) && __GNUC__ >= 2
169 __asm("pushl %0; call __mcount; popl %%ecx"
170 :
171 : "i" (profil)
172 : "ax", "bx", "cx", "dx", "memory");
173#else
174#error
175#endif
176 mcount_overhead = KCOUNT(p, PC_TO_I(p, profil));
177
178 startguprof(p);
179 for (i = 0; i < CALIB_SCALE; i++)
180#if defined(__i386__) && __GNUC__ >= 2
181 __asm("call " __XSTRING(HIDENAME(mexitcount)) "; 1:"
182 : : : "ax", "bx", "cx", "dx", "memory");
183 __asm("movl $1b,%0" : "=rm" (tmp_addr));
184#else
185#error
186#endif
187 mexitcount_overhead = KCOUNT(p, PC_TO_I(p, tmp_addr));
188
189 p->state = GMON_PROF_OFF;
190 stopguprof(p);
191
eac48440 192 cpu_enable_intr();
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193
194 nullfunc_loop_profiled_time = 0;
195 for (tmp_addr = (uintfptr_t)nullfunc_loop_profiled;
196 tmp_addr < (uintfptr_t)nullfunc_loop_profiled_end;
197 tmp_addr += HISTFRACTION * sizeof(HISTCOUNTER))
198 nullfunc_loop_profiled_time += KCOUNT(p, PC_TO_I(p, tmp_addr));
199#define CALIB_DOSCALE(count) (((count) + CALIB_SCALE / 3) / CALIB_SCALE)
200#define c2n(count, freq) ((int)((count) * 1000000000LL / freq))
6ea70f76 201 kprintf("cputime %d, empty_loop %d, nullfunc_loop_profiled %d, mcount %d, mexitcount %d\n",
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202 CALIB_DOSCALE(c2n(cputime_overhead, p->profrate)),
203 CALIB_DOSCALE(c2n(empty_loop_time, p->profrate)),
204 CALIB_DOSCALE(c2n(nullfunc_loop_profiled_time, p->profrate)),
205 CALIB_DOSCALE(c2n(mcount_overhead, p->profrate)),
206 CALIB_DOSCALE(c2n(mexitcount_overhead, p->profrate)));
207 cputime_overhead -= empty_loop_time;
208 mcount_overhead -= empty_loop_time;
209 mexitcount_overhead -= empty_loop_time;
210
211 /*-
212 * Profiling overheads are determined by the times between the
213 * following events:
214 * MC1: mcount() is called
215 * MC2: cputime() (called from mcount()) latches the timer
216 * MC3: mcount() completes
217 * ME1: mexitcount() is called
218 * ME2: cputime() (called from mexitcount()) latches the timer
219 * ME3: mexitcount() completes.
220 * The times between the events vary slightly depending on instruction
221 * combination and cache misses, etc. Attempt to determine the
222 * minimum times. These can be subtracted from the profiling times
223 * without much risk of reducing the profiling times below what they
224 * would be when profiling is not configured. Abbreviate:
225 * ab = minimum time between MC1 and MC3
226 * a = minumum time between MC1 and MC2
227 * b = minimum time between MC2 and MC3
228 * cd = minimum time between ME1 and ME3
229 * c = minimum time between ME1 and ME2
230 * d = minimum time between ME2 and ME3.
231 * These satisfy the relations:
232 * ab <= mcount_overhead (just measured)
233 * a + b <= ab
234 * cd <= mexitcount_overhead (just measured)
235 * c + d <= cd
236 * a + d <= nullfunc_loop_profiled_time (just measured)
237 * a >= 0, b >= 0, c >= 0, d >= 0.
238 * Assume that ab and cd are equal to the minimums.
239 */
240 p->cputime_overhead = CALIB_DOSCALE(cputime_overhead);
241 p->mcount_overhead = CALIB_DOSCALE(mcount_overhead - cputime_overhead);
242 p->mexitcount_overhead = CALIB_DOSCALE(mexitcount_overhead
243 - cputime_overhead);
244 nullfunc_loop_overhead = nullfunc_loop_profiled_time - empty_loop_time;
245 p->mexitcount_post_overhead = CALIB_DOSCALE((mcount_overhead
246 - nullfunc_loop_overhead)
247 / 4);
248 p->mexitcount_pre_overhead = p->mexitcount_overhead
249 + p->cputime_overhead
250 - p->mexitcount_post_overhead;
251 p->mcount_pre_overhead = CALIB_DOSCALE(nullfunc_loop_overhead)
252 - p->mexitcount_post_overhead;
253 p->mcount_post_overhead = p->mcount_overhead
254 + p->cputime_overhead
255 - p->mcount_pre_overhead;
6ea70f76 256 kprintf(
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257"Profiling overheads: mcount: %d+%d, %d+%d; mexitcount: %d+%d, %d+%d nsec\n",
258 c2n(p->cputime_overhead, p->profrate),
259 c2n(p->mcount_overhead, p->profrate),
260 c2n(p->mcount_pre_overhead, p->profrate),
261 c2n(p->mcount_post_overhead, p->profrate),
262 c2n(p->cputime_overhead, p->profrate),
263 c2n(p->mexitcount_overhead, p->profrate),
264 c2n(p->mexitcount_pre_overhead, p->profrate),
265 c2n(p->mexitcount_post_overhead, p->profrate));
6ea70f76 266 kprintf(
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267"Profiling overheads: mcount: %d+%d, %d+%d; mexitcount: %d+%d, %d+%d cycles\n",
268 p->cputime_overhead, p->mcount_overhead,
269 p->mcount_pre_overhead, p->mcount_post_overhead,
270 p->cputime_overhead, p->mexitcount_overhead,
271 p->mexitcount_pre_overhead, p->mexitcount_post_overhead);
272#endif /* GUPROF */
273}
274
275/*
276 * Return kernel profiling information.
277 */
278static int
279sysctl_kern_prof(SYSCTL_HANDLER_ARGS)
280{
281 int *name = (int *) arg1;
282 u_int namelen = arg2;
283 struct gmonparam *gp = &_gmonparam;
284 int error;
285 int state;
286
287 /* all sysctl names at this level are terminal */
288 if (namelen != 1)
289 return (ENOTDIR); /* overloaded */
290
291 switch (name[0]) {
292 case GPROF_STATE:
293 state = gp->state;
294 error = sysctl_handle_int(oidp, &state, 0, req);
295 if (error)
296 return (error);
297 if (!req->newptr)
298 return (0);
299 if (state == GMON_PROF_OFF) {
300 gp->state = state;
301 stopprofclock(&proc0);
302 stopguprof(gp);
303 } else if (state == GMON_PROF_ON) {
304 gp->state = GMON_PROF_OFF;
305 stopguprof(gp);
306 gp->profrate = profhz;
307 startprofclock(&proc0);
308 gp->state = state;
309#ifdef GUPROF
310 } else if (state == GMON_PROF_HIRES) {
311 gp->state = GMON_PROF_OFF;
312 stopprofclock(&proc0);
313 startguprof(gp);
314 gp->state = state;
315#endif
316 } else if (state != gp->state)
317 return (EINVAL);
318 return (0);
319 case GPROF_COUNT:
320 return (sysctl_handle_opaque(oidp,
321 gp->kcount, gp->kcountsize, req));
322 case GPROF_FROMS:
323 return (sysctl_handle_opaque(oidp,
324 gp->froms, gp->fromssize, req));
325 case GPROF_TOS:
326 return (sysctl_handle_opaque(oidp,
327 gp->tos, gp->tossize, req));
328 case GPROF_GMONPARAM:
329 return (sysctl_handle_opaque(oidp, gp, sizeof *gp, req));
330 default:
331 return (EOPNOTSUPP);
332 }
333 /* NOTREACHED */
334}
335
336SYSCTL_NODE(_kern, KERN_PROF, prof, CTLFLAG_RW, sysctl_kern_prof, "");
337#endif /* GPROF */
338
339/*
340 * Profiling system call.
341 *
342 * The scale factor is a fixed point number with 16 bits of fraction, so that
343 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling.
344 */
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345/* ARGSUSED */
346int
753fd850 347sys_profil(struct profil_args *uap)
984263bc 348{
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349 struct proc *p = curproc;
350 struct uprof *upp;
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351
352 if (uap->scale > (1 << 16))
353 return (EINVAL);
354 if (uap->scale == 0) {
355 stopprofclock(p);
356 return (0);
357 }
93328593 358 upp = &p->p_prof;
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359
360 /* Block profile interrupts while changing state. */
e43a034f 361 crit_enter();
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362 upp->pr_off = uap->offset;
363 upp->pr_scale = uap->scale;
364 upp->pr_base = uap->samples;
365 upp->pr_size = uap->size;
366 startprofclock(p);
e43a034f 367 crit_exit();
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368
369 return (0);
370}
371
372/*
373 * Scale is a fixed-point number with the binary point 16 bits
374 * into the value, and is <= 1.0. pc is at most 32 bits, so the
375 * intermediate result is at most 48 bits.
376 */
377#define PC_TO_INDEX(pc, prof) \
378 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \
379 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1)
380
381/*
382 * Collect user-level profiling statistics; called on a profiling tick,
383 * when a process is running in user-mode. This routine may be called
384 * from an interrupt context. We try to update the user profiling buffers
385 * cheaply with fuswintr() and suswintr(). If that fails, we revert to
386 * an AST that will vector us to trap() with a context in which copyin
387 * and copyout will work. Trap will then call addupc_task().
388 *
389 * Note that we may (rarely) not get around to the AST soon enough, and
390 * lose profile ticks when the next tick overwrites this one, but in this
391 * case the system is overloaded and the profile is probably already
392 * inaccurate.
393 */
394void
493c516a 395addupc_intr(struct proc *p, u_long pc, u_int ticks)
984263bc 396{
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397 struct uprof *prof;
398 caddr_t addr;
399 u_int i;
400 int v;
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401
402 if (ticks == 0)
403 return;
93328593 404 prof = &p->p_prof;
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405 if (pc < prof->pr_off ||
406 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size)
407 return; /* out of range; ignore */
408
409 addr = prof->pr_base + i;
410 if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + ticks) == -1) {
411 prof->pr_addr = pc;
412 prof->pr_ticks = ticks;
235957ed 413 need_proftick();
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414 }
415}
416
417/*
418 * Much like before, but we can afford to take faults here. If the
419 * update fails, we simply turn off profiling.
420 */
421void
493c516a 422addupc_task(struct proc *p, u_long pc, u_int ticks)
984263bc 423{
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424 struct uprof *prof;
425 caddr_t addr;
426 u_int i;
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427 u_short v;
428
429 /* Testing P_PROFIL may be unnecessary, but is certainly safe. */
430 if ((p->p_flag & P_PROFIL) == 0 || ticks == 0)
431 return;
432
93328593 433 prof = &p->p_prof;
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434 if (pc < prof->pr_off ||
435 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size)
436 return;
437
438 addr = prof->pr_base + i;
439 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) {
440 v += ticks;
441 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0)
442 return;
443 }
444 stopprofclock(p);
445}