subr_prof.c revision 12657
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 1.12 1995/12/02 17:10:37 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 51static void kmstartup __P((void *)); 52SYSINIT(kmem, SI_SUB_KPROF, SI_ORDER_FIRST, kmstartup, NULL) 53 54struct gmonparam _gmonparam = { GMON_PROF_OFF }; 55 56extern char btext[]; 57extern char etext[]; 58 59static void 60kmstartup(dummy) 61 void *dummy; 62{ 63 char *cp; 64 struct gmonparam *p = &_gmonparam; 65 /* 66 * Round lowpc and highpc to multiples of the density we're using 67 * so the rest of the scaling (here and in gprof) stays in ints. 68 */ 69 p->lowpc = ROUNDDOWN((u_long)btext, HISTFRACTION * sizeof(HISTCOUNTER)); 70 p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER)); 71 p->textsize = p->highpc - p->lowpc; 72 printf("Profiling kernel, textsize=%d [%x..%x]\n", 73 p->textsize, p->lowpc, p->highpc); 74 p->kcountsize = p->textsize / HISTFRACTION; 75 p->hashfraction = HASHFRACTION; 76 p->fromssize = p->textsize / HASHFRACTION; 77 p->tolimit = p->textsize * ARCDENSITY / 100; 78 if (p->tolimit < MINARCS) 79 p->tolimit = MINARCS; 80 else if (p->tolimit > MAXARCS) 81 p->tolimit = MAXARCS; 82 p->tossize = p->tolimit * sizeof(struct tostruct); 83 cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize, 84 M_GPROF, M_NOWAIT); 85 if (cp == 0) { 86 printf("No memory for profiling.\n"); 87 return; 88 } 89 bzero(cp, p->kcountsize + p->tossize + p->fromssize); 90 p->tos = (struct tostruct *)cp; 91 cp += p->tossize; 92 p->kcount = (u_short *)cp; 93 cp += p->kcountsize; 94 p->froms = (u_short *)cp; 95} 96 97/* 98 * Return kernel profiling information. 99 */ 100static int 101sysctl_kern_prof SYSCTL_HANDLER_ARGS 102{ 103 int *name = (int *) arg1; 104 u_int namelen = arg2; 105 struct gmonparam *gp = &_gmonparam; 106 int error; 107 108 /* all sysctl names at this level are terminal */ 109 if (namelen != 1) 110 return (ENOTDIR); /* overloaded */ 111 112 switch (name[0]) { 113 case GPROF_STATE: 114 error = sysctl_handle_int(oidp, &gp->state, 0, req); 115 if (error) 116 return (error); 117 if (gp->state == GMON_PROF_OFF) 118 stopprofclock(&proc0); 119 else 120 startprofclock(&proc0); 121 return (0); 122 case GPROF_COUNT: 123 return (sysctl_handle_opaque(oidp, 124 gp->kcount, gp->kcountsize, req)); 125 case GPROF_FROMS: 126 return (sysctl_handle_opaque(oidp, 127 gp->froms, gp->fromssize, req)); 128 case GPROF_TOS: 129 return (sysctl_handle_opaque(oidp, 130 gp->tos, gp->tossize, req)); 131 case GPROF_GMONPARAM: 132 return (sysctl_handle_opaque(oidp, gp, sizeof *gp, req)); 133 default: 134 return (EOPNOTSUPP); 135 } 136 /* NOTREACHED */ 137} 138 139SYSCTL_NODE(_kern, KERN_PROF, prof, CTLFLAG_RW, sysctl_kern_prof, ""); 140#endif /* GPROF */ 141 142/* 143 * Profiling system call. 144 * 145 * The scale factor is a fixed point number with 16 bits of fraction, so that 146 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 147 */ 148#ifndef _SYS_SYSPROTO_H_ 149struct profil_args { 150 caddr_t samples; 151 u_int size; 152 u_int offset; 153 u_int scale; 154}; 155#endif 156/* ARGSUSED */ 157int 158profil(p, uap, retval) 159 struct proc *p; 160 register struct profil_args *uap; 161 int *retval; 162{ 163 register struct uprof *upp; 164 int s; 165 166 if (uap->scale > (1 << 16)) 167 return (EINVAL); 168 if (uap->scale == 0) { 169 stopprofclock(p); 170 return (0); 171 } 172 upp = &p->p_stats->p_prof; 173 174 /* Block profile interrupts while changing state. */ 175 s = splstatclock(); 176 upp->pr_off = uap->offset; 177 upp->pr_scale = uap->scale; 178 upp->pr_base = uap->samples; 179 upp->pr_size = uap->size; 180 startprofclock(p); 181 splx(s); 182 183 return (0); 184} 185 186/* 187 * Scale is a fixed-point number with the binary point 16 bits 188 * into the value, and is <= 1.0. pc is at most 32 bits, so the 189 * intermediate result is at most 48 bits. 190 */ 191#define PC_TO_INDEX(pc, prof) \ 192 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 193 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 194 195/* 196 * Collect user-level profiling statistics; called on a profiling tick, 197 * when a process is running in user-mode. This routine may be called 198 * from an interrupt context. We try to update the user profiling buffers 199 * cheaply with fuswintr() and suswintr(). If that fails, we revert to 200 * an AST that will vector us to trap() with a context in which copyin 201 * and copyout will work. Trap will then call addupc_task(). 202 * 203 * Note that we may (rarely) not get around to the AST soon enough, and 204 * lose profile ticks when the next tick overwrites this one, but in this 205 * case the system is overloaded and the profile is probably already 206 * inaccurate. 207 */ 208void 209addupc_intr(p, pc, ticks) 210 register struct proc *p; 211 register u_long pc; 212 u_int ticks; 213{ 214 register struct uprof *prof; 215 register caddr_t addr; 216 register u_int i; 217 register int v; 218 219 if (ticks == 0) 220 return; 221 prof = &p->p_stats->p_prof; 222 if (pc < prof->pr_off || 223 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 224 return; /* out of range; ignore */ 225 226 addr = prof->pr_base + i; 227 if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + ticks) == -1) { 228 prof->pr_addr = pc; 229 prof->pr_ticks = ticks; 230 need_proftick(p); 231 } 232} 233 234/* 235 * Much like before, but we can afford to take faults here. If the 236 * update fails, we simply turn off profiling. 237 */ 238void 239addupc_task(p, pc, ticks) 240 register struct proc *p; 241 register u_long pc; 242 u_int ticks; 243{ 244 register struct uprof *prof; 245 register caddr_t addr; 246 register u_int i; 247 u_short v; 248 249 /* Testing P_PROFIL may be unnecessary, but is certainly safe. */ 250 if ((p->p_flag & P_PROFIL) == 0 || ticks == 0) 251 return; 252 253 prof = &p->p_stats->p_prof; 254 if (pc < prof->pr_off || 255 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 256 return; 257 258 addr = prof->pr_base + i; 259 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) { 260 v += ticks; 261 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0) 262 return; 263 } 264 stopprofclock(p); 265} 266