subr_prof.c revision 12221
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 1.9 1995/09/09 18:10:05 davidg 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 <vm/vm.h> 43#include <sys/sysctl.h> 44#include <sys/user.h> 45 46#include <machine/cpu.h> 47 48#ifdef GPROF 49#include <sys/malloc.h> 50#include <sys/gmon.h> 51 52static void kmstartup __P((void *)); 53SYSINIT(kmem, SI_SUB_KPROF, SI_ORDER_FIRST, kmstartup, NULL) 54 55struct gmonparam _gmonparam = { GMON_PROF_OFF }; 56 57extern char btext[]; 58extern char etext[]; 59 60static void 61kmstartup(udata) 62 void *udata; 63{ 64 char *cp; 65 struct gmonparam *p = &_gmonparam; 66 /* 67 * Round lowpc and highpc to multiples of the density we're using 68 * so the rest of the scaling (here and in gprof) stays in ints. 69 */ 70 p->lowpc = ROUNDDOWN((u_long)btext, HISTFRACTION * sizeof(HISTCOUNTER)); 71 p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER)); 72 p->textsize = p->highpc - p->lowpc; 73 printf("Profiling kernel, textsize=%d [%x..%x]\n", 74 p->textsize, p->lowpc, p->highpc); 75 p->kcountsize = p->textsize / HISTFRACTION; 76 p->hashfraction = HASHFRACTION; 77 p->fromssize = p->textsize / HASHFRACTION; 78 p->tolimit = p->textsize * ARCDENSITY / 100; 79 if (p->tolimit < MINARCS) 80 p->tolimit = MINARCS; 81 else if (p->tolimit > MAXARCS) 82 p->tolimit = MAXARCS; 83 p->tossize = p->tolimit * sizeof(struct tostruct); 84 cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize, 85 M_GPROF, M_NOWAIT); 86 if (cp == 0) { 87 printf("No memory for profiling.\n"); 88 return; 89 } 90 bzero(cp, p->kcountsize + p->tossize + p->fromssize); 91 p->tos = (struct tostruct *)cp; 92 cp += p->tossize; 93 p->kcount = (u_short *)cp; 94 cp += p->kcountsize; 95 p->froms = (u_short *)cp; 96} 97 98/* 99 * Return kernel profiling information. 100 */ 101int 102sysctl_doprof(name, namelen, oldp, oldlenp, newp, newlen) 103 int *name; 104 u_int namelen; 105 void *oldp; 106 size_t *oldlenp; 107 void *newp; 108 size_t newlen; 109{ 110 struct gmonparam *gp = &_gmonparam; 111 int error; 112 113 /* all sysctl names at this level are terminal */ 114 if (namelen != 1) 115 return (ENOTDIR); /* overloaded */ 116 117 switch (name[0]) { 118 case GPROF_STATE: 119 error = sysctl_int(oldp, oldlenp, newp, newlen, &gp->state); 120 if (error) 121 return (error); 122 if (gp->state == GMON_PROF_OFF) 123 stopprofclock(&proc0); 124 else 125 startprofclock(&proc0); 126 return (0); 127 case GPROF_COUNT: 128 return (sysctl_struct(oldp, oldlenp, newp, newlen, 129 gp->kcount, gp->kcountsize)); 130 case GPROF_FROMS: 131 return (sysctl_struct(oldp, oldlenp, newp, newlen, 132 gp->froms, gp->fromssize)); 133 case GPROF_TOS: 134 return (sysctl_struct(oldp, oldlenp, newp, newlen, 135 gp->tos, gp->tossize)); 136 case GPROF_GMONPARAM: 137 return (sysctl_rdstruct(oldp, oldlenp, newp, gp, sizeof *gp)); 138 default: 139 return (EOPNOTSUPP); 140 } 141 /* NOTREACHED */ 142} 143#endif /* GPROF */ 144 145/* 146 * Profiling system call. 147 * 148 * The scale factor is a fixed point number with 16 bits of fraction, so that 149 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 150 */ 151#ifndef _SYS_SYSPROTO_H_ 152struct profil_args { 153 caddr_t samples; 154 u_int size; 155 u_int offset; 156 u_int scale; 157}; 158#endif 159/* ARGSUSED */ 160int 161profil(p, uap, retval) 162 struct proc *p; 163 register struct profil_args *uap; 164 int *retval; 165{ 166 register struct uprof *upp; 167 int s; 168 169 if (uap->scale > (1 << 16)) 170 return (EINVAL); 171 if (uap->scale == 0) { 172 stopprofclock(p); 173 return (0); 174 } 175 upp = &p->p_stats->p_prof; 176 177 /* Block profile interrupts while changing state. */ 178 s = splstatclock(); 179 upp->pr_off = uap->offset; 180 upp->pr_scale = uap->scale; 181 upp->pr_base = uap->samples; 182 upp->pr_size = uap->size; 183 startprofclock(p); 184 splx(s); 185 186 return (0); 187} 188 189/* 190 * Scale is a fixed-point number with the binary point 16 bits 191 * into the value, and is <= 1.0. pc is at most 32 bits, so the 192 * intermediate result is at most 48 bits. 193 */ 194#define PC_TO_INDEX(pc, prof) \ 195 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 196 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 197 198/* 199 * Collect user-level profiling statistics; called on a profiling tick, 200 * when a process is running in user-mode. This routine may be called 201 * from an interrupt context. We try to update the user profiling buffers 202 * cheaply with fuswintr() and suswintr(). If that fails, we revert to 203 * an AST that will vector us to trap() with a context in which copyin 204 * and copyout will work. Trap will then call addupc_task(). 205 * 206 * Note that we may (rarely) not get around to the AST soon enough, and 207 * lose profile ticks when the next tick overwrites this one, but in this 208 * case the system is overloaded and the profile is probably already 209 * inaccurate. 210 */ 211void 212addupc_intr(p, pc, ticks) 213 register struct proc *p; 214 register u_long pc; 215 u_int ticks; 216{ 217 register struct uprof *prof; 218 register caddr_t addr; 219 register u_int i; 220 register int v; 221 222 if (ticks == 0) 223 return; 224 prof = &p->p_stats->p_prof; 225 if (pc < prof->pr_off || 226 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 227 return; /* out of range; ignore */ 228 229 addr = prof->pr_base + i; 230 if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + ticks) == -1) { 231 prof->pr_addr = pc; 232 prof->pr_ticks = ticks; 233 need_proftick(p); 234 } 235} 236 237/* 238 * Much like before, but we can afford to take faults here. If the 239 * update fails, we simply turn off profiling. 240 */ 241void 242addupc_task(p, pc, ticks) 243 register struct proc *p; 244 register u_long pc; 245 u_int ticks; 246{ 247 register struct uprof *prof; 248 register caddr_t addr; 249 register u_int i; 250 u_short v; 251 252 /* Testing P_PROFIL may be unnecessary, but is certainly safe. */ 253 if ((p->p_flag & P_PROFIL) == 0 || ticks == 0) 254 return; 255 256 prof = &p->p_stats->p_prof; 257 if (pc < prof->pr_off || 258 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 259 return; 260 261 addr = prof->pr_base + i; 262 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) { 263 v += ticks; 264 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0) 265 return; 266 } 267 stopprofclock(p); 268} 269