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 7.17 (Berkeley) 07/10/92 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 u_short *kcount; 27 extern char etext[]; 28 29 kmstartup() 30 { 31 char *cp; 32 int fsize, tsize, ksize; 33 struct gmonparam *p = &_gmonparam; 34 /* 35 * Round lowpc and highpc to multiples of the density we're using 36 * so the rest of the scaling (here and in gprof) stays in ints. 37 */ 38 p->lowpc = ROUNDDOWN(KERNBASE, HISTFRACTION * sizeof(HISTCOUNTER)); 39 p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER)); 40 p->textsize = p->highpc - p->lowpc; 41 printf("Profiling kernel, textsize=%d [%x..%x]\n", 42 p->textsize, p->lowpc, p->highpc); 43 ksize = p->textsize / HISTFRACTION; 44 fsize = p->textsize / HASHFRACTION; 45 p->tolimit = p->textsize * ARCDENSITY / 100; 46 if (p->tolimit < MINARCS) 47 p->tolimit = MINARCS; 48 else if (p->tolimit > MAXARCS) 49 p->tolimit = MAXARCS; 50 tsize = p->tolimit * sizeof(struct tostruct); 51 cp = (char *)malloc(ksize + fsize + tsize, M_GPROF, M_NOWAIT); 52 if (cp == 0) { 53 printf("No memory for profiling.\n"); 54 return; 55 } 56 bzero(cp, ksize + tsize + fsize); 57 p->tos = (struct tostruct *)cp; 58 cp += tsize; 59 kcount = (u_short *)cp; 60 cp += ksize; 61 p->froms = (u_short *)cp; 62 startprofclock(&proc0); 63 } 64 #endif 65 66 /* 67 * Profiling system call. 68 * 69 * The scale factor is a fixed point number with 16 bits of fraction, so that 70 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 71 */ 72 struct profil_args { 73 caddr_t buf; 74 u_int bufsize; 75 u_int offset; 76 u_int scale; 77 }; 78 /* ARGSUSED */ 79 profil(p, uap, retval) 80 struct proc *p; 81 register struct profil_args *uap; 82 int *retval; 83 { 84 register struct uprof *upp; 85 int s; 86 87 if (uap->scale > (1 << 16)) 88 return (EINVAL); 89 if (uap->scale == 0) { 90 stopprofclock(p); 91 return (0); 92 } 93 upp = &p->p_stats->p_prof; 94 s = splstatclock(); /* block profile interrupts while changing state */ 95 upp->pr_base = uap->buf; 96 upp->pr_size = uap->bufsize; 97 upp->pr_off = uap->offset; 98 upp->pr_scale = uap->scale; 99 startprofclock(p); 100 splx(s); 101 return (0); 102 } 103 104 /* 105 * Scale is a fixed-point number with the binary point 16 bits 106 * into the value, and is <= 1.0. pc is at most 32 bits, so the 107 * intermediate result is at most 48 bits. 108 */ 109 #define PC_TO_INDEX(pc, prof) \ 110 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 111 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 112 113 /* 114 * Collect user-level profiling statistics; called on a profiling tick, 115 * when a process is running in user-mode. This routine may be called 116 * from an interrupt context. We try to update the user profiling buffers 117 * cheaply with fuswintr() and suswintr(). If that fails, we revert to 118 * an AST that will vector us to trap() with a context in which copyin 119 * and copyout will work. Trap will then call addupc_task(). 120 * 121 * Note that we may (rarely) not get around to the AST soon enough, and 122 * lose profile ticks when the next tick overwrites this one, but in this 123 * case the system is overloaded and the profile is probably already 124 * inaccurate. 125 */ 126 void 127 addupc_intr(p, pc, ticks) 128 register struct proc *p; 129 register u_long pc; 130 u_int ticks; 131 { 132 register struct uprof *prof; 133 register caddr_t addr; 134 register u_int i; 135 register int v; 136 137 if (ticks == 0) 138 return; 139 prof = &p->p_stats->p_prof; 140 if (pc < prof->pr_off || 141 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 142 return; /* out of range; ignore */ 143 144 addr = prof->pr_base + i; 145 if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + ticks) == -1) { 146 prof->pr_addr = pc; 147 prof->pr_ticks = ticks; 148 need_proftick(p); 149 } 150 } 151 152 /* 153 * Much like before, but we can afford to take faults here. If the 154 * update fails, we simply turn off profiling. 155 */ 156 void 157 addupc_task(p, pc, ticks) 158 register struct proc *p; 159 register u_long pc; 160 u_int ticks; 161 { 162 register struct uprof *prof; 163 register caddr_t addr; 164 register u_int i; 165 u_short v; 166 167 /* testing SPROFIL may be unnecessary, but is certainly safe */ 168 if ((p->p_flag & SPROFIL) == 0 || ticks == 0) 169 return; 170 171 prof = &p->p_stats->p_prof; 172 if (pc < prof->pr_off || 173 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 174 return; 175 176 addr = prof->pr_base + i; 177 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) { 178 v += ticks; 179 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0) 180 return; 181 } 182 stopprofclock(p); 183 } 184