1 /* $NetBSD: subr_prof.c,v 1.15 1996/12/18 20:12:58 gwr 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)subr_prof.c 8.3 (Berkeley) 9/23/93 36 */ 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/kernel.h> 41 #include <sys/proc.h> 42 #include <sys/user.h> 43 #include <sys/mount.h> 44 #include <sys/syscallargs.h> 45 46 #include <machine/cpu.h> 47 48 #ifdef GPROF 49 #include <sys/malloc.h> 50 #include <sys/gmon.h> 51 52 /* 53 * Froms is actually a bunch of unsigned shorts indexing tos 54 */ 55 struct gmonparam _gmonparam = { GMON_PROF_OFF }; 56 57 /* Actual start of the kernel text segment. */ 58 extern char kernel_text[]; 59 60 extern char etext[]; 61 62 63 void 64 kmstartup() 65 { 66 char *cp; 67 struct gmonparam *p = &_gmonparam; 68 /* 69 * Round lowpc and highpc to multiples of the density we're using 70 * so the rest of the scaling (here and in gprof) stays in ints. 71 */ 72 p->lowpc = ROUNDDOWN(((u_long)kernel_text), 73 HISTFRACTION * sizeof(HISTCOUNTER)); 74 p->highpc = ROUNDUP((u_long)etext, 75 HISTFRACTION * sizeof(HISTCOUNTER)); 76 p->textsize = p->highpc - p->lowpc; 77 printf("Profiling kernel, textsize=%ld [%lx..%lx]\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 = (u_short *)cp; 98 cp += p->kcountsize; 99 p->froms = (u_short *)cp; 100 } 101 102 /* 103 * Return kernel profiling information. 104 */ 105 int 106 sysctl_doprof(name, namelen, oldp, oldlenp, newp, newlen) 107 int *name; 108 u_int namelen; 109 void *oldp; 110 size_t *oldlenp; 111 void *newp; 112 size_t newlen; 113 { 114 struct gmonparam *gp = &_gmonparam; 115 int error; 116 117 /* all sysctl names at this level are terminal */ 118 if (namelen != 1) 119 return (ENOTDIR); /* overloaded */ 120 121 switch (name[0]) { 122 case GPROF_STATE: 123 error = sysctl_int(oldp, oldlenp, newp, newlen, &gp->state); 124 if (error) 125 return (error); 126 if (gp->state == GMON_PROF_OFF) 127 stopprofclock(&proc0); 128 else 129 startprofclock(&proc0); 130 return (0); 131 case GPROF_COUNT: 132 return (sysctl_struct(oldp, oldlenp, newp, newlen, 133 gp->kcount, gp->kcountsize)); 134 case GPROF_FROMS: 135 return (sysctl_struct(oldp, oldlenp, newp, newlen, 136 gp->froms, gp->fromssize)); 137 case GPROF_TOS: 138 return (sysctl_struct(oldp, oldlenp, newp, newlen, 139 gp->tos, gp->tossize)); 140 case GPROF_GMONPARAM: 141 return (sysctl_rdstruct(oldp, oldlenp, newp, gp, sizeof *gp)); 142 default: 143 return (EOPNOTSUPP); 144 } 145 /* NOTREACHED */ 146 } 147 #endif /* GPROF */ 148 149 /* 150 * Profiling system call. 151 * 152 * The scale factor is a fixed point number with 16 bits of fraction, so that 153 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 154 */ 155 /* ARGSUSED */ 156 int 157 sys_profil(p, v, retval) 158 struct proc *p; 159 void *v; 160 register_t *retval; 161 { 162 register struct sys_profil_args /* { 163 syscallarg(caddr_t) samples; 164 syscallarg(u_int) size; 165 syscallarg(u_int) offset; 166 syscallarg(u_int) scale; 167 } */ *uap = v; 168 register struct uprof *upp; 169 int s; 170 171 if (SCARG(uap, scale) > (1 << 16)) 172 return (EINVAL); 173 if (SCARG(uap, scale) == 0) { 174 stopprofclock(p); 175 return (0); 176 } 177 upp = &p->p_stats->p_prof; 178 179 /* Block profile interrupts while changing state. */ 180 s = splstatclock(); 181 upp->pr_off = SCARG(uap, offset); 182 upp->pr_scale = SCARG(uap, scale); 183 upp->pr_base = SCARG(uap, samples); 184 upp->pr_size = SCARG(uap, size); 185 startprofclock(p); 186 splx(s); 187 188 return (0); 189 } 190 191 /* 192 * Scale is a fixed-point number with the binary point 16 bits 193 * into the value, and is <= 1.0. pc is at most 32 bits, so the 194 * intermediate result is at most 48 bits. 195 */ 196 #define PC_TO_INDEX(pc, prof) \ 197 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 198 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 199 200 /* 201 * Collect user-level profiling statistics; called on a profiling tick, 202 * when a process is running in user-mode. This routine may be called 203 * from an interrupt context. We try to update the user profiling buffers 204 * cheaply with fuswintr() and suswintr(). If that fails, we revert to 205 * an AST that will vector us to trap() with a context in which copyin 206 * and copyout will work. Trap will then call addupc_task(). 207 * 208 * Note that we may (rarely) not get around to the AST soon enough, and 209 * lose profile ticks when the next tick overwrites this one, but in this 210 * case the system is overloaded and the profile is probably already 211 * inaccurate. 212 */ 213 void 214 addupc_intr(p, pc, ticks) 215 register struct proc *p; 216 register u_long pc; 217 u_int ticks; 218 { 219 register struct uprof *prof; 220 register caddr_t addr; 221 register u_int i; 222 register int v; 223 224 if (ticks == 0) 225 return; 226 prof = &p->p_stats->p_prof; 227 if (pc < prof->pr_off || 228 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 229 return; /* out of range; ignore */ 230 231 addr = prof->pr_base + i; 232 if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + ticks) == -1) { 233 prof->pr_addr = pc; 234 prof->pr_ticks = ticks; 235 need_proftick(p); 236 } 237 } 238 239 /* 240 * Much like before, but we can afford to take faults here. If the 241 * update fails, we simply turn off profiling. 242 */ 243 void 244 addupc_task(p, pc, ticks) 245 register struct proc *p; 246 register u_long pc; 247 u_int ticks; 248 { 249 register struct uprof *prof; 250 register caddr_t addr; 251 register u_int i; 252 u_short v; 253 254 /* Testing P_PROFIL may be unnecessary, but is certainly safe. */ 255 if ((p->p_flag & P_PROFIL) == 0 || ticks == 0) 256 return; 257 258 prof = &p->p_stats->p_prof; 259 if (pc < prof->pr_off || 260 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 261 return; 262 263 addr = prof->pr_base + i; 264 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) { 265 v += ticks; 266 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0) 267 return; 268 } 269 stopprofclock(p); 270 } 271