1 /* $NetBSD: subr_prof.c,v 1.22 2000/12/10 19:29:31 mycroft 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/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 #include <uvm/uvm_extern.h> 46 #include <sys/sysctl.h> 47 48 #include <machine/cpu.h> 49 50 #ifdef GPROF 51 #include <sys/malloc.h> 52 #include <sys/gmon.h> 53 54 /* 55 * Froms is actually a bunch of unsigned shorts indexing tos 56 */ 57 struct gmonparam _gmonparam = { GMON_PROF_OFF }; 58 59 /* Actual start of the kernel text segment. */ 60 extern char kernel_text[]; 61 62 extern char etext[]; 63 64 65 void 66 kmstartup() 67 { 68 char *cp; 69 struct gmonparam *p = &_gmonparam; 70 /* 71 * Round lowpc and highpc to multiples of the density we're using 72 * so the rest of the scaling (here and in gprof) stays in ints. 73 */ 74 p->lowpc = ROUNDDOWN(((u_long)kernel_text), 75 HISTFRACTION * sizeof(HISTCOUNTER)); 76 p->highpc = ROUNDUP((u_long)etext, 77 HISTFRACTION * sizeof(HISTCOUNTER)); 78 p->textsize = p->highpc - p->lowpc; 79 printf("Profiling kernel, textsize=%ld [%lx..%lx]\n", 80 p->textsize, p->lowpc, p->highpc); 81 p->kcountsize = p->textsize / HISTFRACTION; 82 p->hashfraction = HASHFRACTION; 83 p->fromssize = p->textsize / HASHFRACTION; 84 p->tolimit = p->textsize * ARCDENSITY / 100; 85 if (p->tolimit < MINARCS) 86 p->tolimit = MINARCS; 87 else if (p->tolimit > MAXARCS) 88 p->tolimit = MAXARCS; 89 p->tossize = p->tolimit * sizeof(struct tostruct); 90 cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize, 91 M_GPROF, M_NOWAIT); 92 if (cp == 0) { 93 printf("No memory for profiling.\n"); 94 return; 95 } 96 memset(cp, 0, p->kcountsize + p->tossize + p->fromssize); 97 p->tos = (struct tostruct *)cp; 98 cp += p->tossize; 99 p->kcount = (u_short *)cp; 100 cp += p->kcountsize; 101 p->froms = (u_short *)cp; 102 } 103 104 /* 105 * Return kernel profiling information. 106 */ 107 int 108 sysctl_doprof(name, namelen, oldp, oldlenp, newp, newlen) 109 int *name; 110 u_int namelen; 111 void *oldp; 112 size_t *oldlenp; 113 void *newp; 114 size_t newlen; 115 { 116 struct gmonparam *gp = &_gmonparam; 117 int error; 118 119 /* all sysctl names at this level are terminal */ 120 if (namelen != 1) 121 return (ENOTDIR); /* overloaded */ 122 123 switch (name[0]) { 124 case GPROF_STATE: 125 error = sysctl_int(oldp, oldlenp, newp, newlen, &gp->state); 126 if (error) 127 return (error); 128 if (gp->state == GMON_PROF_OFF) 129 stopprofclock(&proc0); 130 else 131 startprofclock(&proc0); 132 return (0); 133 case GPROF_COUNT: 134 return (sysctl_struct(oldp, oldlenp, newp, newlen, 135 gp->kcount, gp->kcountsize)); 136 case GPROF_FROMS: 137 return (sysctl_struct(oldp, oldlenp, newp, newlen, 138 gp->froms, gp->fromssize)); 139 case GPROF_TOS: 140 return (sysctl_struct(oldp, oldlenp, newp, newlen, 141 gp->tos, gp->tossize)); 142 case GPROF_GMONPARAM: 143 return (sysctl_rdstruct(oldp, oldlenp, newp, gp, sizeof(*gp))); 144 default: 145 return (EOPNOTSUPP); 146 } 147 /* NOTREACHED */ 148 } 149 #endif /* GPROF */ 150 151 /* 152 * Profiling system call. 153 * 154 * The scale factor is a fixed point number with 16 bits of fraction, so that 155 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 156 */ 157 /* ARGSUSED */ 158 int 159 sys_profil(p, v, retval) 160 struct proc *p; 161 void *v; 162 register_t *retval; 163 { 164 struct sys_profil_args /* { 165 syscallarg(caddr_t) samples; 166 syscallarg(u_int) size; 167 syscallarg(u_int) offset; 168 syscallarg(u_int) scale; 169 } */ *uap = v; 170 struct uprof *upp; 171 int s; 172 173 if (SCARG(uap, scale) > (1 << 16)) 174 return (EINVAL); 175 if (SCARG(uap, scale) == 0) { 176 stopprofclock(p); 177 return (0); 178 } 179 upp = &p->p_stats->p_prof; 180 181 /* Block profile interrupts while changing state. */ 182 s = splstatclock(); 183 upp->pr_off = SCARG(uap, offset); 184 upp->pr_scale = SCARG(uap, scale); 185 upp->pr_base = SCARG(uap, samples); 186 upp->pr_size = SCARG(uap, size); 187 startprofclock(p); 188 splx(s); 189 190 return (0); 191 } 192 193 /* 194 * Scale is a fixed-point number with the binary point 16 bits 195 * into the value, and is <= 1.0. pc is at most 32 bits, so the 196 * intermediate result is at most 48 bits. 197 */ 198 #define PC_TO_INDEX(pc, prof) \ 199 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 200 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 201 202 /* 203 * Collect user-level profiling statistics; called on a profiling tick, 204 * when a process is running in user-mode. This routine may be called 205 * from an interrupt context. We try to update the user profiling buffers 206 * cheaply with fuswintr() and suswintr(). If that fails, we revert to 207 * an AST that will vector us to trap() with a context in which copyin 208 * and copyout will work. Trap will then call addupc_task(). 209 * 210 * Note that we may (rarely) not get around to the AST soon enough, and 211 * lose profile ticks when the next tick overwrites this one, but in this 212 * case the system is overloaded and the profile is probably already 213 * inaccurate. 214 */ 215 void 216 addupc_intr(p, pc) 217 struct proc *p; 218 u_long pc; 219 { 220 struct uprof *prof; 221 caddr_t addr; 222 u_int i; 223 int v; 224 225 prof = &p->p_stats->p_prof; 226 if (pc < prof->pr_off || 227 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 228 return; /* out of range; ignore */ 229 230 addr = prof->pr_base + i; 231 if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + 1) == -1) { 232 prof->pr_addr = pc; 233 prof->pr_ticks++; 234 need_proftick(p); 235 } 236 } 237 238 /* 239 * Much like before, but we can afford to take faults here. If the 240 * update fails, we simply turn off profiling. 241 */ 242 void 243 addupc_task(p, pc, ticks) 244 struct proc *p; 245 u_long pc; 246 u_int ticks; 247 { 248 struct uprof *prof; 249 caddr_t addr; 250 u_int i; 251 u_short v; 252 253 /* Testing P_PROFIL may be unnecessary, but is certainly safe. */ 254 if ((p->p_flag & P_PROFIL) == 0 || ticks == 0) 255 return; 256 257 prof = &p->p_stats->p_prof; 258 if (pc < prof->pr_off || 259 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 260 return; 261 262 addr = prof->pr_base + i; 263 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) { 264 v += ticks; 265 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0) 266 return; 267 } 268 stopprofclock(p); 269 } 270