subr_prof.c revision 2956
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 1.3 1994/08/02 07:42:32 davidg Exp $ 35 */ 36 37#include <sys/param.h> 38#include <sys/systm.h> 39#include <sys/kernel.h> 40#include <sys/proc.h> 41#include <sys/user.h> 42#include <machine/cpu.h> 43 44#ifdef GPROF 45#include <sys/malloc.h> 46#include <sys/gmon.h> 47 48/* 49 * Froms is actually a bunch of unsigned shorts indexing tos 50 */ 51struct gmonparam _gmonparam = { GMON_PROF_OFF }; 52 53extern char etext[]; 54 55void 56kmstartup() 57{ 58 char *cp; 59 struct gmonparam *p = &_gmonparam; 60 /* 61 * Round lowpc and highpc to multiples of the density we're using 62 * so the rest of the scaling (here and in gprof) stays in ints. 63 */ 64 p->lowpc = ROUNDDOWN(KERNBASE, HISTFRACTION * sizeof(HISTCOUNTER)); 65 p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER)); 66 p->textsize = p->highpc - p->lowpc; 67 printf("Profiling kernel, textsize=%d [%x..%x]\n", 68 p->textsize, p->lowpc, p->highpc); 69 p->kcountsize = p->textsize / HISTFRACTION; 70 p->hashfraction = HASHFRACTION; 71 p->fromssize = p->textsize / HASHFRACTION; 72 p->tolimit = p->textsize * ARCDENSITY / 100; 73 if (p->tolimit < MINARCS) 74 p->tolimit = MINARCS; 75 else if (p->tolimit > MAXARCS) 76 p->tolimit = MAXARCS; 77 p->tossize = p->tolimit * sizeof(struct tostruct); 78 cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize, 79 M_GPROF, M_NOWAIT); 80 if (cp == 0) { 81 printf("No memory for profiling.\n"); 82 return; 83 } 84 bzero(cp, p->kcountsize + p->tossize + p->fromssize); 85 p->tos = (struct tostruct *)cp; 86 cp += p->tossize; 87 p->kcount = (u_short *)cp; 88 cp += p->kcountsize; 89 p->froms = (u_short *)cp; 90} 91 92/* 93 * Return kernel profiling information. 94 */ 95int 96sysctl_doprof(name, namelen, oldp, oldlenp, newp, newlen) 97 int *name; 98 u_int namelen; 99 void *oldp; 100 size_t *oldlenp; 101 void *newp; 102 size_t newlen; 103{ 104 struct gmonparam *gp = &_gmonparam; 105 int error; 106 107 /* all sysctl names at this level are terminal */ 108 if (namelen != 1) 109 return (ENOTDIR); /* overloaded */ 110 111 switch (name[0]) { 112 case GPROF_STATE: 113 error = sysctl_int(oldp, oldlenp, newp, newlen, &gp->state); 114 if (error) 115 return (error); 116 if (gp->state == GMON_PROF_OFF) 117 stopprofclock(&proc0); 118 else 119 startprofclock(&proc0); 120 return (0); 121 case GPROF_COUNT: 122 return (sysctl_struct(oldp, oldlenp, newp, newlen, 123 gp->kcount, gp->kcountsize)); 124 case GPROF_FROMS: 125 return (sysctl_struct(oldp, oldlenp, newp, newlen, 126 gp->froms, gp->fromssize)); 127 case GPROF_TOS: 128 return (sysctl_struct(oldp, oldlenp, newp, newlen, 129 gp->tos, gp->tossize)); 130 case GPROF_GMONPARAM: 131 return (sysctl_rdstruct(oldp, oldlenp, newp, gp, sizeof *gp)); 132 default: 133 return (EOPNOTSUPP); 134 } 135 /* NOTREACHED */ 136} 137#endif /* GPROF */ 138 139/* 140 * Profiling system call. 141 * 142 * The scale factor is a fixed point number with 16 bits of fraction, so that 143 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 144 */ 145struct profil_args { 146 caddr_t samples; 147 u_int size; 148 u_int offset; 149 u_int scale; 150}; 151/* ARGSUSED */ 152int 153profil(p, uap, retval) 154 struct proc *p; 155 register struct profil_args *uap; 156 int *retval; 157{ 158 register struct uprof *upp; 159 int s; 160 161 if (uap->scale > (1 << 16)) 162 return (EINVAL); 163 if (uap->scale == 0) { 164 stopprofclock(p); 165 return (0); 166 } 167 upp = &p->p_stats->p_prof; 168 169 /* Block profile interrupts while changing state. */ 170 s = splstatclock(); 171 upp->pr_off = uap->offset; 172 upp->pr_scale = uap->scale; 173 upp->pr_base = uap->samples; 174 upp->pr_size = uap->size; 175 startprofclock(p); 176 splx(s); 177 178 return (0); 179} 180 181/* 182 * Scale is a fixed-point number with the binary point 16 bits 183 * into the value, and is <= 1.0. pc is at most 32 bits, so the 184 * intermediate result is at most 48 bits. 185 */ 186#define PC_TO_INDEX(pc, prof) \ 187 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 188 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 189 190/* 191 * Collect user-level profiling statistics; called on a profiling tick, 192 * when a process is running in user-mode. This routine may be called 193 * from an interrupt context. We try to update the user profiling buffers 194 * cheaply with fuswintr() and suswintr(). If that fails, we revert to 195 * an AST that will vector us to trap() with a context in which copyin 196 * and copyout will work. Trap will then call addupc_task(). 197 * 198 * Note that we may (rarely) not get around to the AST soon enough, and 199 * lose profile ticks when the next tick overwrites this one, but in this 200 * case the system is overloaded and the profile is probably already 201 * inaccurate. 202 */ 203void 204addupc_intr(p, pc, ticks) 205 register struct proc *p; 206 register u_long pc; 207 u_int ticks; 208{ 209 register struct uprof *prof; 210 register caddr_t addr; 211 register u_int i; 212 register int v; 213 214 if (ticks == 0) 215 return; 216 prof = &p->p_stats->p_prof; 217 if (pc < prof->pr_off || 218 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 219 return; /* out of range; ignore */ 220 221 addr = prof->pr_base + i; 222 if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + ticks) == -1) { 223 prof->pr_addr = pc; 224 prof->pr_ticks = ticks; 225 need_proftick(p); 226 } 227} 228 229/* 230 * Much like before, but we can afford to take faults here. If the 231 * update fails, we simply turn off profiling. 232 */ 233void 234addupc_task(p, pc, ticks) 235 register struct proc *p; 236 register u_long pc; 237 u_int ticks; 238{ 239 register struct uprof *prof; 240 register caddr_t addr; 241 register u_int i; 242 u_short v; 243 244 /* Testing P_PROFIL may be unnecessary, but is certainly safe. */ 245 if ((p->p_flag & P_PROFIL) == 0 || ticks == 0) 246 return; 247 248 prof = &p->p_stats->p_prof; 249 if (pc < prof->pr_off || 250 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 251 return; 252 253 addr = prof->pr_base + i; 254 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) { 255 v += ticks; 256 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0) 257 return; 258 } 259 stopprofclock(p); 260} 261