1 /* $OpenBSD: subr_prof.c,v 1.9 2001/11/06 19:53:20 miod Exp $ */ 2 /* $NetBSD: subr_prof.c,v 1.12 1996/04/22 01:38:50 christos Exp $ */ 3 4 /*- 5 * Copyright (c) 1982, 1986, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)subr_prof.c 8.3 (Berkeley) 9/23/93 37 */ 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/kernel.h> 42 #include <sys/proc.h> 43 #include <sys/user.h> 44 #include <sys/mount.h> 45 #include <sys/syscallargs.h> 46 47 #include <machine/cpu.h> 48 49 #ifdef GPROF 50 #include <sys/malloc.h> 51 #include <sys/gmon.h> 52 #include <uvm/uvm_extern.h> 53 54 /* 55 * Froms is actually a bunch of unsigned shorts indexing tos 56 */ 57 struct gmonparam _gmonparam = { GMON_PROF_OFF }; 58 59 extern char etext[]; 60 61 62 void 63 kmstartup() 64 { 65 char *cp; 66 struct gmonparam *p = &_gmonparam; 67 int size; 68 69 /* 70 * Round lowpc and highpc to multiples of the density we're using 71 * so the rest of the scaling (here and in gprof) stays in ints. 72 */ 73 p->lowpc = ROUNDDOWN(KERNBASE, HISTFRACTION * sizeof(HISTCOUNTER)); 74 p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER)); 75 p->textsize = p->highpc - p->lowpc; 76 printf("Profiling kernel, textsize=%ld [%lx..%lx]\n", 77 p->textsize, p->lowpc, p->highpc); 78 p->kcountsize = p->textsize / HISTFRACTION; 79 p->hashfraction = HASHFRACTION; 80 p->fromssize = p->textsize / HASHFRACTION; 81 p->tolimit = p->textsize * ARCDENSITY / 100; 82 if (p->tolimit < MINARCS) 83 p->tolimit = MINARCS; 84 else if (p->tolimit > MAXARCS) 85 p->tolimit = MAXARCS; 86 p->tossize = p->tolimit * sizeof(struct tostruct); 87 size = p->kcountsize + p->fromssize + p->tossize; 88 cp = (char *)uvm_km_zalloc(kernel_map, round_page(size)); 89 if (cp == 0) { 90 printf("No memory for profiling.\n"); 91 return; 92 } 93 p->tos = (struct tostruct *)cp; 94 cp += p->tossize; 95 p->kcount = (u_short *)cp; 96 cp += p->kcountsize; 97 p->froms = (u_short *)cp; 98 } 99 100 /* 101 * Return kernel profiling information. 102 */ 103 int 104 sysctl_doprof(name, namelen, oldp, oldlenp, newp, newlen) 105 int *name; 106 u_int namelen; 107 void *oldp; 108 size_t *oldlenp; 109 void *newp; 110 size_t newlen; 111 { 112 struct gmonparam *gp = &_gmonparam; 113 int error; 114 115 /* all sysctl names at this level are terminal */ 116 if (namelen != 1) 117 return (ENOTDIR); /* overloaded */ 118 119 switch (name[0]) { 120 case GPROF_STATE: 121 error = sysctl_int(oldp, oldlenp, newp, newlen, &gp->state); 122 if (error) 123 return (error); 124 if (gp->state == GMON_PROF_OFF) 125 stopprofclock(&proc0); 126 else 127 startprofclock(&proc0); 128 return (0); 129 case GPROF_COUNT: 130 return (sysctl_struct(oldp, oldlenp, newp, newlen, 131 gp->kcount, gp->kcountsize)); 132 case GPROF_FROMS: 133 return (sysctl_struct(oldp, oldlenp, newp, newlen, 134 gp->froms, gp->fromssize)); 135 case GPROF_TOS: 136 return (sysctl_struct(oldp, oldlenp, newp, newlen, 137 gp->tos, gp->tossize)); 138 case GPROF_GMONPARAM: 139 return (sysctl_rdstruct(oldp, oldlenp, newp, gp, sizeof *gp)); 140 default: 141 return (EOPNOTSUPP); 142 } 143 /* NOTREACHED */ 144 } 145 #endif /* GPROF */ 146 147 /* 148 * Profiling system call. 149 * 150 * The scale factor is a fixed point number with 16 bits of fraction, so that 151 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 152 */ 153 /* ARGSUSED */ 154 int 155 sys_profil(p, v, retval) 156 struct proc *p; 157 void *v; 158 register_t *retval; 159 { 160 register struct sys_profil_args /* { 161 syscallarg(char *) samples; 162 syscallarg(u_int) size; 163 syscallarg(u_int) offset; 164 syscallarg(u_int) scale; 165 } */ *uap = v; 166 register struct uprof *upp; 167 int s; 168 169 if (SCARG(uap, scale) > (1 << 16)) 170 return (EINVAL); 171 if (SCARG(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 = SCARG(uap, offset); 180 upp->pr_scale = SCARG(uap, scale); 181 upp->pr_base = (caddr_t)SCARG(uap, samples); 182 upp->pr_size = SCARG(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 */ 211 void 212 addupc_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 */ 241 void 242 addupc_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