1 /* $NetBSD: subr_prof.c,v 1.25 2001/11/12 15:25:21 lukem 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 8.4 (Berkeley) 2/14/95 36 */ 37 38 #include <sys/cdefs.h> 39 __KERNEL_RCSID(0, "$NetBSD: subr_prof.c,v 1.25 2001/11/12 15:25:21 lukem Exp $"); 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/kernel.h> 44 #include <sys/proc.h> 45 #include <sys/user.h> 46 #include <sys/mount.h> 47 #include <sys/syscallargs.h> 48 #include <sys/sysctl.h> 49 50 #include <machine/cpu.h> 51 52 #ifdef GPROF 53 #include <sys/malloc.h> 54 #include <sys/gmon.h> 55 56 /* 57 * Froms is actually a bunch of unsigned shorts indexing tos 58 */ 59 struct gmonparam _gmonparam = { GMON_PROF_OFF }; 60 61 /* Actual start of the kernel text segment. */ 62 extern char kernel_text[]; 63 64 extern char etext[]; 65 66 67 void 68 kmstartup() 69 { 70 char *cp; 71 struct gmonparam *p = &_gmonparam; 72 /* 73 * Round lowpc and highpc to multiples of the density we're using 74 * so the rest of the scaling (here and in gprof) stays in ints. 75 */ 76 p->lowpc = ROUNDDOWN(((u_long)kernel_text), 77 HISTFRACTION * sizeof(HISTCOUNTER)); 78 p->highpc = ROUNDUP((u_long)etext, 79 HISTFRACTION * sizeof(HISTCOUNTER)); 80 p->textsize = p->highpc - p->lowpc; 81 printf("Profiling kernel, textsize=%ld [%lx..%lx]\n", 82 p->textsize, p->lowpc, p->highpc); 83 p->kcountsize = p->textsize / HISTFRACTION; 84 p->hashfraction = HASHFRACTION; 85 p->fromssize = p->textsize / HASHFRACTION; 86 p->tolimit = p->textsize * ARCDENSITY / 100; 87 if (p->tolimit < MINARCS) 88 p->tolimit = MINARCS; 89 else if (p->tolimit > MAXARCS) 90 p->tolimit = MAXARCS; 91 p->tossize = p->tolimit * sizeof(struct tostruct); 92 cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize, 93 M_GPROF, M_NOWAIT); 94 if (cp == 0) { 95 printf("No memory for profiling.\n"); 96 return; 97 } 98 memset(cp, 0, p->kcountsize + p->tossize + p->fromssize); 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 int 110 sysctl_doprof(name, namelen, oldp, oldlenp, newp, newlen) 111 int *name; 112 u_int namelen; 113 void *oldp; 114 size_t *oldlenp; 115 void *newp; 116 size_t newlen; 117 { 118 struct gmonparam *gp = &_gmonparam; 119 int error; 120 121 /* all sysctl names at this level are terminal */ 122 if (namelen != 1) 123 return (ENOTDIR); /* overloaded */ 124 125 /* Check we got the necessary memory at startup. */ 126 if (gp->kcount == NULL) 127 return (EOPNOTSUPP); 128 129 switch (name[0]) { 130 case GPROF_STATE: 131 error = sysctl_int(oldp, oldlenp, newp, newlen, &gp->state); 132 if (error) 133 return (error); 134 if (gp->state == GMON_PROF_OFF) 135 stopprofclock(&proc0); 136 else 137 startprofclock(&proc0); 138 return (0); 139 case GPROF_COUNT: 140 return (sysctl_struct(oldp, oldlenp, newp, newlen, 141 gp->kcount, gp->kcountsize)); 142 case GPROF_FROMS: 143 return (sysctl_struct(oldp, oldlenp, newp, newlen, 144 gp->froms, gp->fromssize)); 145 case GPROF_TOS: 146 return (sysctl_struct(oldp, oldlenp, newp, newlen, 147 gp->tos, gp->tossize)); 148 case GPROF_GMONPARAM: 149 return (sysctl_rdstruct(oldp, oldlenp, newp, gp, sizeof(*gp))); 150 default: 151 return (EOPNOTSUPP); 152 } 153 /* NOTREACHED */ 154 } 155 #endif /* GPROF */ 156 157 /* 158 * Profiling system call. 159 * 160 * The scale factor is a fixed point number with 16 bits of fraction, so that 161 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 162 */ 163 /* ARGSUSED */ 164 int 165 sys_profil(p, v, retval) 166 struct proc *p; 167 void *v; 168 register_t *retval; 169 { 170 struct sys_profil_args /* { 171 syscallarg(caddr_t) samples; 172 syscallarg(u_int) size; 173 syscallarg(u_int) offset; 174 syscallarg(u_int) scale; 175 } */ *uap = v; 176 struct uprof *upp; 177 int s; 178 179 if (SCARG(uap, scale) > (1 << 16)) 180 return (EINVAL); 181 if (SCARG(uap, scale) == 0) { 182 stopprofclock(p); 183 return (0); 184 } 185 upp = &p->p_stats->p_prof; 186 187 /* Block profile interrupts while changing state. */ 188 s = splstatclock(); 189 upp->pr_off = SCARG(uap, offset); 190 upp->pr_scale = SCARG(uap, scale); 191 upp->pr_base = SCARG(uap, samples); 192 upp->pr_size = SCARG(uap, size); 193 startprofclock(p); 194 splx(s); 195 196 return (0); 197 } 198 199 /* 200 * Scale is a fixed-point number with the binary point 16 bits 201 * into the value, and is <= 1.0. pc is at most 32 bits, so the 202 * intermediate result is at most 48 bits. 203 */ 204 #define PC_TO_INDEX(pc, prof) \ 205 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 206 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 207 208 /* 209 * Collect user-level profiling statistics; called on a profiling tick, 210 * when a process is running in user-mode. This routine may be called 211 * from an interrupt context. We try to update the user profiling buffers 212 * cheaply with fuswintr() and suswintr(). If that fails, we revert to 213 * an AST that will vector us to trap() with a context in which copyin 214 * and copyout will work. Trap will then call addupc_task(). 215 * 216 * Note that we may (rarely) not get around to the AST soon enough, and 217 * lose profile ticks when the next tick overwrites this one, but in this 218 * case the system is overloaded and the profile is probably already 219 * inaccurate. 220 */ 221 void 222 addupc_intr(p, pc) 223 struct proc *p; 224 u_long pc; 225 { 226 struct uprof *prof; 227 caddr_t addr; 228 u_int i; 229 int v; 230 231 prof = &p->p_stats->p_prof; 232 if (pc < prof->pr_off || 233 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 234 return; /* out of range; ignore */ 235 236 addr = prof->pr_base + i; 237 if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + 1) == -1) { 238 prof->pr_addr = pc; 239 prof->pr_ticks++; 240 need_proftick(p); 241 } 242 } 243 244 /* 245 * Much like before, but we can afford to take faults here. If the 246 * update fails, we simply turn off profiling. 247 */ 248 void 249 addupc_task(p, pc, ticks) 250 struct proc *p; 251 u_long pc; 252 u_int ticks; 253 { 254 struct uprof *prof; 255 caddr_t addr; 256 u_int i; 257 u_short v; 258 259 /* Testing P_PROFIL may be unnecessary, but is certainly safe. */ 260 if ((p->p_flag & P_PROFIL) == 0 || ticks == 0) 261 return; 262 263 prof = &p->p_stats->p_prof; 264 if (pc < prof->pr_off || 265 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 266 return; 267 268 addr = prof->pr_base + i; 269 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) { 270 v += ticks; 271 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0) 272 return; 273 } 274 stopprofclock(p); 275 } 276