1 /*- 2 * Copyright (c) 1982, 1986, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)subr_prof.c 8.3 (Berkeley) 9/23/93 34 * $Id: subr_prof.c,v 1.10 1995/11/12 06:43:04 bde Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/sysproto.h> 40 #include <sys/kernel.h> 41 #include <sys/proc.h> 42 #include <vm/vm.h> 43 #include <sys/sysctl.h> 44 #include <sys/user.h> 45 46 #include <machine/cpu.h> 47 48 #ifdef GPROF 49 #include <sys/malloc.h> 50 #include <sys/gmon.h> 51 52 static void kmstartup __P((void *)); 53 SYSINIT(kmem, SI_SUB_KPROF, SI_ORDER_FIRST, kmstartup, NULL) 54 55 struct gmonparam _gmonparam = { GMON_PROF_OFF }; 56 57 extern char btext[]; 58 extern char etext[]; 59 60 static void 61 kmstartup(udata) 62 void *udata; 63 { 64 char *cp; 65 struct gmonparam *p = &_gmonparam; 66 /* 67 * Round lowpc and highpc to multiples of the density we're using 68 * so the rest of the scaling (here and in gprof) stays in ints. 69 */ 70 p->lowpc = ROUNDDOWN((u_long)btext, HISTFRACTION * sizeof(HISTCOUNTER)); 71 p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER)); 72 p->textsize = p->highpc - p->lowpc; 73 printf("Profiling kernel, textsize=%d [%x..%x]\n", 74 p->textsize, p->lowpc, p->highpc); 75 p->kcountsize = p->textsize / HISTFRACTION; 76 p->hashfraction = HASHFRACTION; 77 p->fromssize = p->textsize / HASHFRACTION; 78 p->tolimit = p->textsize * ARCDENSITY / 100; 79 if (p->tolimit < MINARCS) 80 p->tolimit = MINARCS; 81 else if (p->tolimit > MAXARCS) 82 p->tolimit = MAXARCS; 83 p->tossize = p->tolimit * sizeof(struct tostruct); 84 cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize, 85 M_GPROF, M_NOWAIT); 86 if (cp == 0) { 87 printf("No memory for profiling.\n"); 88 return; 89 } 90 bzero(cp, p->kcountsize + p->tossize + p->fromssize); 91 p->tos = (struct tostruct *)cp; 92 cp += p->tossize; 93 p->kcount = (u_short *)cp; 94 cp += p->kcountsize; 95 p->froms = (u_short *)cp; 96 } 97 98 /* 99 * Return kernel profiling information. 100 */ 101 static int 102 sysctl_kern_prof SYSCTL_HANDLER_ARGS 103 { 104 int *name = (int *) arg1; 105 u_int namelen = arg2; 106 struct gmonparam *gp = &_gmonparam; 107 int error; 108 109 /* all sysctl names at this level are terminal */ 110 if (namelen != 1) 111 return (ENOTDIR); /* overloaded */ 112 113 switch (name[0]) { 114 case GPROF_STATE: 115 error = sysctl_handle_int(oidp, &gp->state, 0, req); 116 if (error) 117 return (error); 118 if (gp->state == GMON_PROF_OFF) 119 stopprofclock(&proc0); 120 else 121 startprofclock(&proc0); 122 return (0); 123 case GPROF_COUNT: 124 return (sysctl_handle_opaque(oidp, 125 gp->kcount, gp->kcountsize, req)); 126 case GPROF_FROMS: 127 return (sysctl_handle_opaque(oidp, 128 gp->froms, gp->fromssize, req)); 129 case GPROF_TOS: 130 return (sysctl_handle_opaque(oidp, 131 gp->tos, gp->tossize, req)); 132 case GPROF_GMONPARAM: 133 return (sysctl_handle_opaque(oidp, gp, sizeof *gp, req)); 134 default: 135 return (EOPNOTSUPP); 136 } 137 /* NOTREACHED */ 138 } 139 140 SYSCTL_NODE(_kern, KERN_PROF, prof, CTLFLAG_RW, sysctl_kern_prof, ""); 141 #endif /* GPROF */ 142 143 /* 144 * Profiling system call. 145 * 146 * The scale factor is a fixed point number with 16 bits of fraction, so that 147 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 148 */ 149 #ifndef _SYS_SYSPROTO_H_ 150 struct profil_args { 151 caddr_t samples; 152 u_int size; 153 u_int offset; 154 u_int scale; 155 }; 156 #endif 157 /* ARGSUSED */ 158 int 159 profil(p, uap, retval) 160 struct proc *p; 161 register struct profil_args *uap; 162 int *retval; 163 { 164 register struct uprof *upp; 165 int s; 166 167 if (uap->scale > (1 << 16)) 168 return (EINVAL); 169 if (uap->scale == 0) { 170 stopprofclock(p); 171 return (0); 172 } 173 upp = &p->p_stats->p_prof; 174 175 /* Block profile interrupts while changing state. */ 176 s = splstatclock(); 177 upp->pr_off = uap->offset; 178 upp->pr_scale = uap->scale; 179 upp->pr_base = uap->samples; 180 upp->pr_size = uap->size; 181 startprofclock(p); 182 splx(s); 183 184 return (0); 185 } 186 187 /* 188 * Scale is a fixed-point number with the binary point 16 bits 189 * into the value, and is <= 1.0. pc is at most 32 bits, so the 190 * intermediate result is at most 48 bits. 191 */ 192 #define PC_TO_INDEX(pc, prof) \ 193 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 194 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 195 196 /* 197 * Collect user-level profiling statistics; called on a profiling tick, 198 * when a process is running in user-mode. This routine may be called 199 * from an interrupt context. We try to update the user profiling buffers 200 * cheaply with fuswintr() and suswintr(). If that fails, we revert to 201 * an AST that will vector us to trap() with a context in which copyin 202 * and copyout will work. Trap will then call addupc_task(). 203 * 204 * Note that we may (rarely) not get around to the AST soon enough, and 205 * lose profile ticks when the next tick overwrites this one, but in this 206 * case the system is overloaded and the profile is probably already 207 * inaccurate. 208 */ 209 void 210 addupc_intr(p, pc, ticks) 211 register struct proc *p; 212 register u_long pc; 213 u_int ticks; 214 { 215 register struct uprof *prof; 216 register caddr_t addr; 217 register u_int i; 218 register int v; 219 220 if (ticks == 0) 221 return; 222 prof = &p->p_stats->p_prof; 223 if (pc < prof->pr_off || 224 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 225 return; /* out of range; ignore */ 226 227 addr = prof->pr_base + i; 228 if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + ticks) == -1) { 229 prof->pr_addr = pc; 230 prof->pr_ticks = ticks; 231 need_proftick(p); 232 } 233 } 234 235 /* 236 * Much like before, but we can afford to take faults here. If the 237 * update fails, we simply turn off profiling. 238 */ 239 void 240 addupc_task(p, pc, ticks) 241 register struct proc *p; 242 register u_long pc; 243 u_int ticks; 244 { 245 register struct uprof *prof; 246 register caddr_t addr; 247 register u_int i; 248 u_short v; 249 250 /* Testing P_PROFIL may be unnecessary, but is certainly safe. */ 251 if ((p->p_flag & P_PROFIL) == 0 || ticks == 0) 252 return; 253 254 prof = &p->p_stats->p_prof; 255 if (pc < prof->pr_off || 256 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 257 return; 258 259 addr = prof->pr_base + i; 260 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) { 261 v += ticks; 262 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0) 263 return; 264 } 265 stopprofclock(p); 266 } 267