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 * $Id: subr_prof.c,v 1.15 1995/12/26 01:21:39 bde Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/sysproto.h> 40 #include <sys/kernel.h> 41 #include <sys/proc.h> 42 #include <sys/resourcevar.h> 43 #include <sys/sysctl.h> 44 45 #include <machine/cpu.h> 46 47 #ifdef GPROF 48 #include <sys/malloc.h> 49 #include <sys/gmon.h> 50 51 static void kmstartup __P((void *)); 52 SYSINIT(kmem, SI_SUB_KPROF, SI_ORDER_FIRST, kmstartup, NULL) 53 54 struct gmonparam _gmonparam = { GMON_PROF_OFF }; 55 56 extern char btext[]; 57 extern char etext[]; 58 59 static void 60 kmstartup(dummy) 61 void *dummy; 62 { 63 char *cp; 64 struct gmonparam *p = &_gmonparam; 65 #ifdef GUPROF 66 fptrint_t kmstartup_addr; 67 int i; 68 #endif 69 70 /* 71 * Round lowpc and highpc to multiples of the density we're using 72 * so the rest of the scaling (here and in gprof) stays in ints. 73 */ 74 p->lowpc = ROUNDDOWN((u_long)btext, HISTFRACTION * sizeof(HISTCOUNTER)); 75 p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER)); 76 p->textsize = p->highpc - p->lowpc; 77 printf("Profiling kernel, textsize=%d [%x..%x]\n", 78 p->textsize, p->lowpc, p->highpc); 79 p->kcountsize = p->textsize / HISTFRACTION; 80 p->hashfraction = HASHFRACTION; 81 p->fromssize = p->textsize / HASHFRACTION; 82 p->tolimit = p->textsize * ARCDENSITY / 100; 83 if (p->tolimit < MINARCS) 84 p->tolimit = MINARCS; 85 else if (p->tolimit > MAXARCS) 86 p->tolimit = MAXARCS; 87 p->tossize = p->tolimit * sizeof(struct tostruct); 88 cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize, 89 M_GPROF, M_NOWAIT); 90 if (cp == 0) { 91 printf("No memory for profiling.\n"); 92 return; 93 } 94 bzero(cp, p->kcountsize + p->tossize + p->fromssize); 95 p->tos = (struct tostruct *)cp; 96 cp += p->tossize; 97 p->kcount = (HISTCOUNTER *)cp; 98 cp += p->kcountsize; 99 p->froms = (u_short *)cp; 100 101 #ifdef GUPROF 102 /* 103 * Initialize pointers to overhead counters. 104 */ 105 p->cputime_count = &KCOUNT(p, PC_TO_I(p, cputime)); 106 p->mcount_count = &KCOUNT(p, PC_TO_I(p, mcount)); 107 p->mexitcount_count = &KCOUNT(p, PC_TO_I(p, mexitcount)); 108 109 /* 110 * Determine overheads. 111 */ 112 disable_intr(); 113 p->state = GMON_PROF_HIRES; 114 115 p->cputime_overhead = 0; 116 (void)cputime(); 117 for (i = 0; i < CALIB_SCALE; i++) 118 p->cputime_overhead += cputime(); 119 120 (void)cputime(); 121 for (i = 0; i < CALIB_SCALE; i++) 122 #if defined(i386) && __GNUC__ >= 2 123 /* 124 * Underestimate slightly by always calling __mcount, never 125 * mcount. 126 */ 127 asm("pushl %0; call __mcount; popl %%ecx" 128 : 129 : "i" (kmstartup) 130 : "ax", "bx", "cx", "dx", "memory"); 131 #else 132 #error 133 #endif 134 p->mcount_overhead = KCOUNT(p, PC_TO_I(p, kmstartup)); 135 136 (void)cputime(); 137 for (i = 0; i < CALIB_SCALE; i++) 138 #if defined(i386) && __GNUC__ >= 2 139 asm("call mexitcount; 1:" 140 : : : "ax", "bx", "cx", "dx", "memory"); 141 asm("movl $1b,%0" : "=rm" (kmstartup_addr)); 142 #else 143 #error 144 #endif 145 p->mexitcount_overhead = KCOUNT(p, PC_TO_I(p, kmstartup_addr)); 146 147 p->state = GMON_PROF_OFF; 148 enable_intr(); 149 150 p->mcount_overhead_sub = p->mcount_overhead - p->cputime_overhead; 151 p->mexitcount_overhead_sub = p->mexitcount_overhead 152 - p->cputime_overhead; 153 printf("Profiling overheads: %u+%u %u+%u\n", 154 p->cputime_overhead, p->mcount_overhead_sub, 155 p->cputime_overhead, p->mexitcount_overhead_sub); 156 p->cputime_overhead_frac = p->cputime_overhead % CALIB_SCALE; 157 p->cputime_overhead /= CALIB_SCALE; 158 p->mcount_overhead_frac = p->mcount_overhead_sub % CALIB_SCALE; 159 p->mcount_overhead_sub /= CALIB_SCALE; 160 p->mcount_overhead /= CALIB_SCALE; 161 p->mexitcount_overhead_frac = p->mexitcount_overhead_sub % CALIB_SCALE; 162 p->mexitcount_overhead_sub /= CALIB_SCALE; 163 p->mexitcount_overhead /= CALIB_SCALE; 164 #endif /* GUPROF */ 165 } 166 167 /* 168 * Return kernel profiling information. 169 */ 170 static int 171 sysctl_kern_prof SYSCTL_HANDLER_ARGS 172 { 173 int *name = (int *) arg1; 174 u_int namelen = arg2; 175 struct gmonparam *gp = &_gmonparam; 176 int error; 177 int state; 178 179 /* all sysctl names at this level are terminal */ 180 if (namelen != 1) 181 return (ENOTDIR); /* overloaded */ 182 183 switch (name[0]) { 184 case GPROF_STATE: 185 state = gp->state; 186 error = sysctl_handle_int(oidp, &state, 0, req); 187 if (error) 188 return (error); 189 if (!req->newptr) 190 return (0); 191 if (state == GMON_PROF_OFF) { 192 stopprofclock(&proc0); 193 gp->state = state; 194 } else if (state == GMON_PROF_ON) { 195 gp->profrate = profhz; 196 gp->state = state; 197 startprofclock(&proc0); 198 #ifdef GUPROF 199 } else if (state == GMON_PROF_HIRES) { 200 gp->profrate = 1193182; /* XXX */ 201 stopprofclock(&proc0); 202 gp->state = state; 203 #endif 204 } else if (state != gp->state) 205 return (EINVAL); 206 return (0); 207 case GPROF_COUNT: 208 return (sysctl_handle_opaque(oidp, 209 gp->kcount, gp->kcountsize, req)); 210 case GPROF_FROMS: 211 return (sysctl_handle_opaque(oidp, 212 gp->froms, gp->fromssize, req)); 213 case GPROF_TOS: 214 return (sysctl_handle_opaque(oidp, 215 gp->tos, gp->tossize, req)); 216 case GPROF_GMONPARAM: 217 return (sysctl_handle_opaque(oidp, gp, sizeof *gp, req)); 218 default: 219 return (EOPNOTSUPP); 220 } 221 /* NOTREACHED */ 222 } 223 224 SYSCTL_NODE(_kern, KERN_PROF, prof, CTLFLAG_RW, sysctl_kern_prof, ""); 225 #endif /* GPROF */ 226 227 /* 228 * Profiling system call. 229 * 230 * The scale factor is a fixed point number with 16 bits of fraction, so that 231 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 232 */ 233 #ifndef _SYS_SYSPROTO_H_ 234 struct profil_args { 235 caddr_t samples; 236 u_int size; 237 u_int offset; 238 u_int scale; 239 }; 240 #endif 241 /* ARGSUSED */ 242 int 243 profil(p, uap, retval) 244 struct proc *p; 245 register struct profil_args *uap; 246 int *retval; 247 { 248 register struct uprof *upp; 249 int s; 250 251 if (uap->scale > (1 << 16)) 252 return (EINVAL); 253 if (uap->scale == 0) { 254 stopprofclock(p); 255 return (0); 256 } 257 upp = &p->p_stats->p_prof; 258 259 /* Block profile interrupts while changing state. */ 260 s = splstatclock(); 261 upp->pr_off = uap->offset; 262 upp->pr_scale = uap->scale; 263 upp->pr_base = uap->samples; 264 upp->pr_size = uap->size; 265 startprofclock(p); 266 splx(s); 267 268 return (0); 269 } 270 271 /* 272 * Scale is a fixed-point number with the binary point 16 bits 273 * into the value, and is <= 1.0. pc is at most 32 bits, so the 274 * intermediate result is at most 48 bits. 275 */ 276 #define PC_TO_INDEX(pc, prof) \ 277 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 278 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 279 280 /* 281 * Collect user-level profiling statistics; called on a profiling tick, 282 * when a process is running in user-mode. This routine may be called 283 * from an interrupt context. We try to update the user profiling buffers 284 * cheaply with fuswintr() and suswintr(). If that fails, we revert to 285 * an AST that will vector us to trap() with a context in which copyin 286 * and copyout will work. Trap will then call addupc_task(). 287 * 288 * Note that we may (rarely) not get around to the AST soon enough, and 289 * lose profile ticks when the next tick overwrites this one, but in this 290 * case the system is overloaded and the profile is probably already 291 * inaccurate. 292 */ 293 void 294 addupc_intr(p, pc, ticks) 295 register struct proc *p; 296 register u_long pc; 297 u_int ticks; 298 { 299 register struct uprof *prof; 300 register caddr_t addr; 301 register u_int i; 302 register int v; 303 304 if (ticks == 0) 305 return; 306 prof = &p->p_stats->p_prof; 307 if (pc < prof->pr_off || 308 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 309 return; /* out of range; ignore */ 310 311 addr = prof->pr_base + i; 312 if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + ticks) == -1) { 313 prof->pr_addr = pc; 314 prof->pr_ticks = ticks; 315 need_proftick(p); 316 } 317 } 318 319 /* 320 * Much like before, but we can afford to take faults here. If the 321 * update fails, we simply turn off profiling. 322 */ 323 void 324 addupc_task(p, pc, ticks) 325 register struct proc *p; 326 register u_long pc; 327 u_int ticks; 328 { 329 register struct uprof *prof; 330 register caddr_t addr; 331 register u_int i; 332 u_short v; 333 334 /* Testing P_PROFIL may be unnecessary, but is certainly safe. */ 335 if ((p->p_flag & P_PROFIL) == 0 || ticks == 0) 336 return; 337 338 prof = &p->p_stats->p_prof; 339 if (pc < prof->pr_off || 340 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 341 return; 342 343 addr = prof->pr_base + i; 344 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) { 345 v += ticks; 346 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0) 347 return; 348 } 349 stopprofclock(p); 350 } 351