subr_prof.c revision 1.48.4.1
1 /* $NetBSD: subr_prof.c,v 1.48.4.1 2019/06/10 22:09:03 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1982, 1986, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)subr_prof.c 8.4 (Berkeley) 2/14/95 32 */ 33 34 #include <sys/cdefs.h> 35 __KERNEL_RCSID(0, "$NetBSD: subr_prof.c,v 1.48.4.1 2019/06/10 22:09:03 christos Exp $"); 36 37 #ifdef _KERNEL_OPT 38 #include "opt_gprof.h" 39 #endif 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/kernel.h> 44 #include <sys/proc.h> 45 #include <sys/mount.h> 46 #include <sys/syscallargs.h> 47 #include <sys/sysctl.h> 48 49 #include <sys/cpu.h> 50 51 #ifdef GPROF 52 #include <sys/malloc.h> 53 #include <sys/gmon.h> 54 55 MALLOC_DEFINE(M_GPROF, "gprof", "kernel profiling buffer"); 56 57 /* 58 * Froms is actually a bunch of unsigned shorts indexing tos 59 */ 60 struct gmonparam _gmonparam = { .state = GMON_PROF_OFF }; 61 62 /* Actual start of the kernel text segment. */ 63 extern char kernel_text[]; 64 65 extern char etext[]; 66 67 68 void 69 kmstartup(void) 70 { 71 char *cp; 72 struct gmonparam *p = &_gmonparam; 73 /* 74 * Round lowpc and highpc to multiples of the density we're using 75 * so the rest of the scaling (here and in gprof) stays in ints. 76 */ 77 p->lowpc = rounddown(((u_long)kernel_text), 78 HISTFRACTION * sizeof(HISTCOUNTER)); 79 p->highpc = roundup((u_long)etext, 80 HISTFRACTION * sizeof(HISTCOUNTER)); 81 p->textsize = p->highpc - p->lowpc; 82 printf("Profiling kernel, textsize=%ld [%lx..%lx]\n", 83 p->textsize, p->lowpc, p->highpc); 84 p->kcountsize = p->textsize / HISTFRACTION; 85 p->hashfraction = HASHFRACTION; 86 p->fromssize = p->textsize / HASHFRACTION; 87 p->tolimit = p->textsize * ARCDENSITY / 100; 88 if (p->tolimit < MINARCS) 89 p->tolimit = MINARCS; 90 else if (p->tolimit > MAXARCS) 91 p->tolimit = MAXARCS; 92 p->tossize = p->tolimit * sizeof(struct tostruct); 93 cp = malloc(p->kcountsize + p->fromssize + p->tossize, 94 M_GPROF, M_NOWAIT | M_ZERO); 95 if (cp == 0) { 96 printf("No memory for profiling.\n"); 97 return; 98 } 99 p->tos = (struct tostruct *)cp; 100 cp += p->tossize; 101 p->kcount = (u_short *)cp; 102 cp += p->kcountsize; 103 p->froms = (u_short *)cp; 104 } 105 106 /* 107 * Return kernel profiling information. 108 */ 109 /* 110 * sysctl helper routine for kern.profiling subtree. enables/disables 111 * kernel profiling and gives out copies of the profiling data. 112 */ 113 static int 114 sysctl_kern_profiling(SYSCTLFN_ARGS) 115 { 116 struct gmonparam *gp = &_gmonparam; 117 int error; 118 struct sysctlnode node; 119 120 node = *rnode; 121 122 switch (node.sysctl_num) { 123 case GPROF_STATE: 124 node.sysctl_data = &gp->state; 125 break; 126 case GPROF_COUNT: 127 node.sysctl_data = gp->kcount; 128 node.sysctl_size = gp->kcountsize; 129 break; 130 case GPROF_FROMS: 131 node.sysctl_data = gp->froms; 132 node.sysctl_size = gp->fromssize; 133 break; 134 case GPROF_TOS: 135 node.sysctl_data = gp->tos; 136 node.sysctl_size = gp->tossize; 137 break; 138 case GPROF_GMONPARAM: 139 node.sysctl_data = gp; 140 node.sysctl_size = sizeof(*gp); 141 break; 142 default: 143 return (EOPNOTSUPP); 144 } 145 146 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 147 if (error || newp == NULL) 148 return (error); 149 150 if (node.sysctl_num == GPROF_STATE) { 151 mutex_spin_enter(&proc0.p_stmutex); 152 if (gp->state == GMON_PROF_OFF) 153 stopprofclock(&proc0); 154 else 155 startprofclock(&proc0); 156 mutex_spin_exit(&proc0.p_stmutex); 157 } 158 159 return (0); 160 } 161 162 SYSCTL_SETUP(sysctl_kern_gprof_setup, "sysctl kern.profiling subtree setup") 163 { 164 165 sysctl_createv(clog, 0, NULL, NULL, 166 CTLFLAG_PERMANENT, 167 CTLTYPE_NODE, "profiling", 168 SYSCTL_DESCR("Profiling information (available)"), 169 NULL, 0, NULL, 0, 170 CTL_KERN, KERN_PROF, CTL_EOL); 171 172 sysctl_createv(clog, 0, NULL, NULL, 173 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 174 CTLTYPE_INT, "state", 175 SYSCTL_DESCR("Profiling state"), 176 sysctl_kern_profiling, 0, NULL, 0, 177 CTL_KERN, KERN_PROF, GPROF_STATE, CTL_EOL); 178 sysctl_createv(clog, 0, NULL, NULL, 179 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 180 CTLTYPE_STRUCT, "count", 181 SYSCTL_DESCR("Array of statistical program counters"), 182 sysctl_kern_profiling, 0, NULL, 0, 183 CTL_KERN, KERN_PROF, GPROF_COUNT, CTL_EOL); 184 sysctl_createv(clog, 0, NULL, NULL, 185 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 186 CTLTYPE_STRUCT, "froms", 187 SYSCTL_DESCR("Array indexed by program counter of " 188 "call-from points"), 189 sysctl_kern_profiling, 0, NULL, 0, 190 CTL_KERN, KERN_PROF, GPROF_FROMS, CTL_EOL); 191 sysctl_createv(clog, 0, NULL, NULL, 192 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 193 CTLTYPE_STRUCT, "tos", 194 SYSCTL_DESCR("Array of structures describing " 195 "destination of calls and their counts"), 196 sysctl_kern_profiling, 0, NULL, 0, 197 CTL_KERN, KERN_PROF, GPROF_TOS, CTL_EOL); 198 sysctl_createv(clog, 0, NULL, NULL, 199 CTLFLAG_PERMANENT, 200 CTLTYPE_STRUCT, "gmonparam", 201 SYSCTL_DESCR("Structure giving the sizes of the above " 202 "arrays"), 203 sysctl_kern_profiling, 0, NULL, 0, 204 CTL_KERN, KERN_PROF, GPROF_GMONPARAM, CTL_EOL); 205 } 206 #endif /* GPROF */ 207 208 /* 209 * Profiling system call. 210 * 211 * The scale factor is a fixed point number with 16 bits of fraction, so that 212 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 213 */ 214 /* ARGSUSED */ 215 int 216 sys_profil(struct lwp *l, const struct sys_profil_args *uap, register_t *retval) 217 { 218 /* { 219 syscallarg(char *) samples; 220 syscallarg(size_t) size; 221 syscallarg(u_long) offset; 222 syscallarg(u_int) scale; 223 } */ 224 struct proc *p = l->l_proc; 225 struct uprof *upp; 226 227 if (SCARG(uap, scale) > (1 << 16)) 228 return (EINVAL); 229 if (SCARG(uap, scale) == 0) { 230 mutex_spin_enter(&p->p_stmutex); 231 stopprofclock(p); 232 mutex_spin_exit(&p->p_stmutex); 233 return (0); 234 } 235 upp = &p->p_stats->p_prof; 236 237 /* Block profile interrupts while changing state. */ 238 mutex_spin_enter(&p->p_stmutex); 239 upp->pr_off = SCARG(uap, offset); 240 upp->pr_scale = SCARG(uap, scale); 241 upp->pr_base = SCARG(uap, samples); 242 upp->pr_size = SCARG(uap, size); 243 startprofclock(p); 244 mutex_spin_exit(&p->p_stmutex); 245 246 return (0); 247 } 248 249 /* 250 * Scale is a fixed-point number with the binary point 16 bits 251 * into the value, and is <= 1.0. pc is at most 32 bits, so the 252 * intermediate result is at most 48 bits. 253 */ 254 #define PC_TO_INDEX(pc, prof) \ 255 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 256 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 257 258 /* 259 * Collect user-level profiling statistics; called on a profiling tick, 260 * when a process is running in user-mode. This routine may be called 261 * from an interrupt context. We schedule an AST that will vector us 262 * to trap() with a context in which copyin and copyout will work. 263 * Trap will then call addupc_task(). 264 * 265 * XXX We could use ufetch/ustore here if the profile buffers were 266 * wired. 267 * 268 * Note that we may (rarely) not get around to the AST soon enough, and 269 * lose profile ticks when the next tick overwrites this one, but in this 270 * case the system is overloaded and the profile is probably already 271 * inaccurate. 272 */ 273 void 274 addupc_intr(struct lwp *l, u_long pc) 275 { 276 struct uprof *prof; 277 struct proc *p; 278 u_int i; 279 280 p = l->l_proc; 281 282 KASSERT(mutex_owned(&p->p_stmutex)); 283 284 prof = &p->p_stats->p_prof; 285 if (pc < prof->pr_off || 286 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 287 return; /* out of range; ignore */ 288 289 mutex_spin_exit(&p->p_stmutex); 290 291 /* XXXSMP */ 292 prof->pr_addr = pc; 293 prof->pr_ticks++; 294 cpu_need_proftick(l); 295 296 mutex_spin_enter(&p->p_stmutex); 297 } 298 299 /* 300 * Much like before, but we can afford to take faults here. If the 301 * update fails, we simply turn off profiling. 302 */ 303 void 304 addupc_task(struct lwp *l, u_long pc, u_int ticks) 305 { 306 struct uprof *prof; 307 struct proc *p; 308 void *addr; 309 int error; 310 u_int i; 311 u_short v; 312 313 p = l->l_proc; 314 315 if (ticks == 0) 316 return; 317 318 mutex_spin_enter(&p->p_stmutex); 319 prof = &p->p_stats->p_prof; 320 321 /* Testing P_PROFIL may be unnecessary, but is certainly safe. */ 322 if ((p->p_stflag & PST_PROFIL) == 0 || pc < prof->pr_off || 323 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) { 324 mutex_spin_exit(&p->p_stmutex); 325 return; 326 } 327 328 addr = prof->pr_base + i; 329 mutex_spin_exit(&p->p_stmutex); 330 if ((error = copyin(addr, (void *)&v, sizeof(v))) == 0) { 331 v += ticks; 332 error = copyout((void *)&v, addr, sizeof(v)); 333 } 334 if (error != 0) { 335 mutex_spin_enter(&p->p_stmutex); 336 stopprofclock(p); 337 mutex_spin_exit(&p->p_stmutex); 338 } 339 } 340
Indexes created Tue Sep 30 20:09:53 GMT 2025