1 /* $NetBSD: subr_prof.c,v 1.28 2003/08/07 16:31:54 agc 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)subr_prof.c 8.4 (Berkeley) 2/14/95 32 */ 33 34 #include <sys/cdefs.h> 35 __KERNEL_RCSID(0, "$NetBSD: subr_prof.c,v 1.28 2003/08/07 16:31:54 agc Exp $"); 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/kernel.h> 40 #include <sys/proc.h> 41 #include <sys/user.h> 42 #include <sys/mount.h> 43 #include <sys/sa.h> 44 #include <sys/syscallargs.h> 45 #include <sys/sysctl.h> 46 47 #include <machine/cpu.h> 48 49 #ifdef GPROF 50 #include <sys/malloc.h> 51 #include <sys/gmon.h> 52 53 MALLOC_DEFINE(M_GPROF, "gprof", "kernel profiling buffer"); 54 55 /* 56 * Froms is actually a bunch of unsigned shorts indexing tos 57 */ 58 struct gmonparam _gmonparam = { GMON_PROF_OFF }; 59 60 /* Actual start of the kernel text segment. */ 61 extern char kernel_text[]; 62 63 extern char etext[]; 64 65 66 void 67 kmstartup() 68 { 69 char *cp; 70 struct gmonparam *p = &_gmonparam; 71 /* 72 * Round lowpc and highpc to multiples of the density we're using 73 * so the rest of the scaling (here and in gprof) stays in ints. 74 */ 75 p->lowpc = ROUNDDOWN(((u_long)kernel_text), 76 HISTFRACTION * sizeof(HISTCOUNTER)); 77 p->highpc = ROUNDUP((u_long)etext, 78 HISTFRACTION * sizeof(HISTCOUNTER)); 79 p->textsize = p->highpc - p->lowpc; 80 printf("Profiling kernel, textsize=%ld [%lx..%lx]\n", 81 p->textsize, p->lowpc, p->highpc); 82 p->kcountsize = p->textsize / HISTFRACTION; 83 p->hashfraction = HASHFRACTION; 84 p->fromssize = p->textsize / HASHFRACTION; 85 p->tolimit = p->textsize * ARCDENSITY / 100; 86 if (p->tolimit < MINARCS) 87 p->tolimit = MINARCS; 88 else if (p->tolimit > MAXARCS) 89 p->tolimit = MAXARCS; 90 p->tossize = p->tolimit * sizeof(struct tostruct); 91 cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize, 92 M_GPROF, M_NOWAIT); 93 if (cp == 0) { 94 printf("No memory for profiling.\n"); 95 return; 96 } 97 memset(cp, 0, p->kcountsize + p->tossize + p->fromssize); 98 p->tos = (struct tostruct *)cp; 99 cp += p->tossize; 100 p->kcount = (u_short *)cp; 101 cp += p->kcountsize; 102 p->froms = (u_short *)cp; 103 } 104 105 /* 106 * Return kernel profiling information. 107 */ 108 int 109 sysctl_doprof(name, namelen, oldp, oldlenp, newp, newlen) 110 int *name; 111 u_int namelen; 112 void *oldp; 113 size_t *oldlenp; 114 void *newp; 115 size_t newlen; 116 { 117 struct gmonparam *gp = &_gmonparam; 118 int error; 119 120 /* all sysctl names at this level are terminal */ 121 if (namelen != 1) 122 return (ENOTDIR); /* overloaded */ 123 124 /* Check we got the necessary memory at startup. */ 125 if (gp->kcount == NULL) 126 return (EOPNOTSUPP); 127 128 switch (name[0]) { 129 case GPROF_STATE: 130 error = sysctl_int(oldp, oldlenp, newp, newlen, &gp->state); 131 if (error) 132 return (error); 133 if (gp->state == GMON_PROF_OFF) 134 stopprofclock(&proc0); 135 else 136 startprofclock(&proc0); 137 return (0); 138 case GPROF_COUNT: 139 return (sysctl_struct(oldp, oldlenp, newp, newlen, 140 gp->kcount, gp->kcountsize)); 141 case GPROF_FROMS: 142 return (sysctl_struct(oldp, oldlenp, newp, newlen, 143 gp->froms, gp->fromssize)); 144 case GPROF_TOS: 145 return (sysctl_struct(oldp, oldlenp, newp, newlen, 146 gp->tos, gp->tossize)); 147 case GPROF_GMONPARAM: 148 return (sysctl_rdstruct(oldp, oldlenp, newp, gp, sizeof(*gp))); 149 default: 150 return (EOPNOTSUPP); 151 } 152 /* NOTREACHED */ 153 } 154 #endif /* GPROF */ 155 156 /* 157 * Profiling system call. 158 * 159 * The scale factor is a fixed point number with 16 bits of fraction, so that 160 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 161 */ 162 /* ARGSUSED */ 163 int 164 sys_profil(l, v, retval) 165 struct lwp *l; 166 void *v; 167 register_t *retval; 168 { 169 struct sys_profil_args /* { 170 syscallarg(caddr_t) samples; 171 syscallarg(u_int) size; 172 syscallarg(u_int) offset; 173 syscallarg(u_int) scale; 174 } */ *uap = v; 175 struct proc *p = l->l_proc; 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