1 /*- 2 * Copyright (c) 1982, 1986 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)subr_prof.c 7.18 (Berkeley) 04/27/93 8 */ 9 10 #include <sys/param.h> 11 #include <sys/systm.h> 12 #include <sys/kernel.h> 13 #include <sys/proc.h> 14 #include <sys/user.h> 15 #include <machine/cpu.h> 16 17 #ifdef GPROF 18 #include <sys/malloc.h> 19 #include <sys/gmon.h> 20 21 /* 22 * Froms is actually a bunch of unsigned shorts indexing tos 23 */ 24 struct gmonparam _gmonparam = { GMON_PROF_OFF }; 25 26 extern char etext[]; 27 28 kmstartup() 29 { 30 char *cp; 31 struct gmonparam *p = &_gmonparam; 32 /* 33 * Round lowpc and highpc to multiples of the density we're using 34 * so the rest of the scaling (here and in gprof) stays in ints. 35 */ 36 p->lowpc = ROUNDDOWN(KERNBASE, HISTFRACTION * sizeof(HISTCOUNTER)); 37 p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER)); 38 p->textsize = p->highpc - p->lowpc; 39 printf("Profiling kernel, textsize=%d [%x..%x]\n", 40 p->textsize, p->lowpc, p->highpc); 41 p->kcountsize = p->textsize / HISTFRACTION; 42 p->fromssize = p->textsize / HASHFRACTION; 43 p->tolimit = p->textsize * ARCDENSITY / 100; 44 if (p->tolimit < MINARCS) 45 p->tolimit = MINARCS; 46 else if (p->tolimit > MAXARCS) 47 p->tolimit = MAXARCS; 48 p->tossize = p->tolimit * sizeof(struct tostruct); 49 cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize, 50 M_GPROF, M_NOWAIT); 51 if (cp == 0) { 52 printf("No memory for profiling.\n"); 53 return; 54 } 55 bzero(cp, p->kcountsize + p->tossize + p->fromssize); 56 p->tos = (struct tostruct *)cp; 57 cp += p->tossize; 58 p->kcount = (u_short *)cp; 59 cp += p->kcountsize; 60 p->froms = (u_short *)cp; 61 startprofclock(&proc0); 62 } 63 64 /* 65 * Return kernel profiling information. 66 */ 67 sysctl_doprof(name, namelen, oldp, oldlenp, newp, newlen, p) 68 int *name; 69 u_int namelen; 70 void *oldp; 71 size_t *oldlenp; 72 void *newp; 73 size_t newlen; 74 { 75 struct gmonparam *gp = &_gmonparam; 76 77 /* all sysctl names at this level are terminal */ 78 if (namelen != 1) 79 return (ENOTDIR); /* overloaded */ 80 81 switch (name[0]) { 82 case GPROF_STATE: 83 return (sysctl_int(oldp, oldlenp, newp, newlen, &gp->state)); 84 case GPROF_COUNT: 85 return (sysctl_struct(oldp, oldlenp, newp, newlen, 86 gp->kcount, gp->kcountsize)); 87 case GPROF_FROMS: 88 return (sysctl_struct(oldp, oldlenp, newp, newlen, 89 gp->froms, gp->fromssize)); 90 case GPROF_TOS: 91 return (sysctl_struct(oldp, oldlenp, newp, newlen, 92 gp->tos, gp->tossize)); 93 default: 94 return (EOPNOTSUPP); 95 } 96 /* NOTREACHED */ 97 } 98 #endif /* GPROF */ 99 100 /* 101 * Profiling system call. 102 * 103 * The scale factor is a fixed point number with 16 bits of fraction, so that 104 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 105 */ 106 struct profil_args { 107 caddr_t buf; 108 u_int bufsize; 109 u_int offset; 110 u_int scale; 111 }; 112 /* ARGSUSED */ 113 profil(p, uap, retval) 114 struct proc *p; 115 register struct profil_args *uap; 116 int *retval; 117 { 118 register struct uprof *upp; 119 int s; 120 121 if (uap->scale > (1 << 16)) 122 return (EINVAL); 123 if (uap->scale == 0) { 124 stopprofclock(p); 125 return (0); 126 } 127 upp = &p->p_stats->p_prof; 128 s = splstatclock(); /* block profile interrupts while changing state */ 129 upp->pr_base = uap->buf; 130 upp->pr_size = uap->bufsize; 131 upp->pr_off = uap->offset; 132 upp->pr_scale = uap->scale; 133 startprofclock(p); 134 splx(s); 135 return (0); 136 } 137 138 /* 139 * Scale is a fixed-point number with the binary point 16 bits 140 * into the value, and is <= 1.0. pc is at most 32 bits, so the 141 * intermediate result is at most 48 bits. 142 */ 143 #define PC_TO_INDEX(pc, prof) \ 144 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 145 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 146 147 /* 148 * Collect user-level profiling statistics; called on a profiling tick, 149 * when a process is running in user-mode. This routine may be called 150 * from an interrupt context. We try to update the user profiling buffers 151 * cheaply with fuswintr() and suswintr(). If that fails, we revert to 152 * an AST that will vector us to trap() with a context in which copyin 153 * and copyout will work. Trap will then call addupc_task(). 154 * 155 * Note that we may (rarely) not get around to the AST soon enough, and 156 * lose profile ticks when the next tick overwrites this one, but in this 157 * case the system is overloaded and the profile is probably already 158 * inaccurate. 159 */ 160 void 161 addupc_intr(p, pc, ticks) 162 register struct proc *p; 163 register u_long pc; 164 u_int ticks; 165 { 166 register struct uprof *prof; 167 register caddr_t addr; 168 register u_int i; 169 register int v; 170 171 if (ticks == 0) 172 return; 173 prof = &p->p_stats->p_prof; 174 if (pc < prof->pr_off || 175 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 176 return; /* out of range; ignore */ 177 178 addr = prof->pr_base + i; 179 if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + ticks) == -1) { 180 prof->pr_addr = pc; 181 prof->pr_ticks = ticks; 182 need_proftick(p); 183 } 184 } 185 186 /* 187 * Much like before, but we can afford to take faults here. If the 188 * update fails, we simply turn off profiling. 189 */ 190 void 191 addupc_task(p, pc, ticks) 192 register struct proc *p; 193 register u_long pc; 194 u_int ticks; 195 { 196 register struct uprof *prof; 197 register caddr_t addr; 198 register u_int i; 199 u_short v; 200 201 /* testing SPROFIL may be unnecessary, but is certainly safe */ 202 if ((p->p_flag & SPROFIL) == 0 || ticks == 0) 203 return; 204 205 prof = &p->p_stats->p_prof; 206 if (pc < prof->pr_off || 207 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 208 return; 209 210 addr = prof->pr_base + i; 211 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) { 212 v += ticks; 213 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0) 214 return; 215 } 216 stopprofclock(p); 217 } 218