subr_prof.c revision 82717
11541Srgrimes/*- 21541Srgrimes * Copyright (c) 1982, 1986, 1993 31541Srgrimes * The Regents of the University of California. All rights reserved. 41541Srgrimes * 51541Srgrimes * Redistribution and use in source and binary forms, with or without 61541Srgrimes * modification, are permitted provided that the following conditions 71541Srgrimes * are met: 81541Srgrimes * 1. Redistributions of source code must retain the above copyright 91541Srgrimes * notice, this list of conditions and the following disclaimer. 101541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111541Srgrimes * notice, this list of conditions and the following disclaimer in the 121541Srgrimes * documentation and/or other materials provided with the distribution. 131541Srgrimes * 3. All advertising materials mentioning features or use of this software 141541Srgrimes * must display the following acknowledgement: 151541Srgrimes * This product includes software developed by the University of 161541Srgrimes * California, Berkeley and its contributors. 171541Srgrimes * 4. Neither the name of the University nor the names of its contributors 181541Srgrimes * may be used to endorse or promote products derived from this software 191541Srgrimes * without specific prior written permission. 201541Srgrimes * 211541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311541Srgrimes * SUCH DAMAGE. 321541Srgrimes * 331541Srgrimes * @(#)subr_prof.c 8.3 (Berkeley) 9/23/93 3450477Speter * $FreeBSD: head/sys/kern/subr_prof.c 82717 2001-09-01 05:47:58Z dillon $ 351541Srgrimes */ 361541Srgrimes 371541Srgrimes#include <sys/param.h> 381541Srgrimes#include <sys/systm.h> 3912221Sbde#include <sys/sysproto.h> 4052147Sbde#include <sys/kernel.h> 4176166Smarkm#include <sys/lock.h> 4276166Smarkm#include <sys/mutex.h> 431541Srgrimes#include <sys/proc.h> 4412657Sbde#include <sys/resourcevar.h> 4552147Sbde#include <sys/sysctl.h> 467090Sbde 471541Srgrimes#include <machine/cpu.h> 481541Srgrimes 491541Srgrimes#ifdef GPROF 501541Srgrimes#include <sys/malloc.h> 511541Srgrimes#include <sys/gmon.h> 5246548Sbde#undef MCOUNT 531541Srgrimes 5430354Sphkstatic MALLOC_DEFINE(M_GPROF, "gprof", "kernel profiling buffer"); 5530309Sphk 5610653Sdgstatic void kmstartup __P((void *)); 5710358SjulianSYSINIT(kmem, SI_SUB_KPROF, SI_ORDER_FIRST, kmstartup, NULL) 5810358Sjulian 591541Srgrimesstruct gmonparam _gmonparam = { GMON_PROF_OFF }; 601541Srgrimes 6119000Sbde#ifdef GUPROF 6246548Sbde#include <machine/asmacros.h> 6346548Sbde 6419000Sbdevoid 6519000Sbdenullfunc_loop_profiled() 6619000Sbde{ 6719000Sbde int i; 6819000Sbde 6919000Sbde for (i = 0; i < CALIB_SCALE; i++) 7019000Sbde nullfunc_profiled(); 7119000Sbde} 7219000Sbde 7320396Sbde#define nullfunc_loop_profiled_end nullfunc_profiled /* XXX */ 7420396Sbde 7519000Sbdevoid 7619000Sbdenullfunc_profiled() 7719000Sbde{ 7819000Sbde} 7919000Sbde#endif /* GUPROF */ 8019000Sbde 8110407Sbdestatic void 8212569Sbdekmstartup(dummy) 8312569Sbde void *dummy; 841541Srgrimes{ 851541Srgrimes char *cp; 861541Srgrimes struct gmonparam *p = &_gmonparam; 8713107Sbde#ifdef GUPROF 8819000Sbde int cputime_overhead; 8919000Sbde int empty_loop_time; 9019000Sbde int i; 9119000Sbde int mcount_overhead; 9219000Sbde int mexitcount_overhead; 9319000Sbde int nullfunc_loop_overhead; 9419000Sbde int nullfunc_loop_profiled_time; 9537629Sbde uintfptr_t tmp_addr; 9674903Sjhb critical_t savecrit; 9713107Sbde#endif 9813107Sbde 991541Srgrimes /* 1001541Srgrimes * Round lowpc and highpc to multiples of the density we're using 1011541Srgrimes * so the rest of the scaling (here and in gprof) stays in ints. 1021541Srgrimes */ 1036009Sbde p->lowpc = ROUNDDOWN((u_long)btext, HISTFRACTION * sizeof(HISTCOUNTER)); 1041541Srgrimes p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER)); 1051541Srgrimes p->textsize = p->highpc - p->lowpc; 10619000Sbde printf("Profiling kernel, textsize=%lu [%x..%x]\n", 1071541Srgrimes p->textsize, p->lowpc, p->highpc); 1081541Srgrimes p->kcountsize = p->textsize / HISTFRACTION; 1091541Srgrimes p->hashfraction = HASHFRACTION; 1101541Srgrimes p->fromssize = p->textsize / HASHFRACTION; 1111541Srgrimes p->tolimit = p->textsize * ARCDENSITY / 100; 1121541Srgrimes if (p->tolimit < MINARCS) 1131541Srgrimes p->tolimit = MINARCS; 1141541Srgrimes else if (p->tolimit > MAXARCS) 1151541Srgrimes p->tolimit = MAXARCS; 1161541Srgrimes p->tossize = p->tolimit * sizeof(struct tostruct); 1171541Srgrimes cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize, 11869781Sdwmalone M_GPROF, M_NOWAIT | M_ZERO); 1191541Srgrimes if (cp == 0) { 1201541Srgrimes printf("No memory for profiling.\n"); 1211541Srgrimes return; 1221541Srgrimes } 1231541Srgrimes p->tos = (struct tostruct *)cp; 1241541Srgrimes cp += p->tossize; 12513107Sbde p->kcount = (HISTCOUNTER *)cp; 1261541Srgrimes cp += p->kcountsize; 1271541Srgrimes p->froms = (u_short *)cp; 12813107Sbde 12913107Sbde#ifdef GUPROF 13019000Sbde /* Initialize pointers to overhead counters. */ 13113107Sbde p->cputime_count = &KCOUNT(p, PC_TO_I(p, cputime)); 13213107Sbde p->mcount_count = &KCOUNT(p, PC_TO_I(p, mcount)); 13313107Sbde p->mexitcount_count = &KCOUNT(p, PC_TO_I(p, mexitcount)); 13413107Sbde 13513107Sbde /* 13619000Sbde * Disable interrupts to avoid interference while we calibrate 13719000Sbde * things. 13813107Sbde */ 13974903Sjhb savecrit = critical_enter(); 14013107Sbde 14119000Sbde /* 14219000Sbde * Determine overheads. 14319000Sbde * XXX this needs to be repeated for each useful timer/counter. 14419000Sbde */ 14519000Sbde cputime_overhead = 0; 14619000Sbde startguprof(p); 14713107Sbde for (i = 0; i < CALIB_SCALE; i++) 14819000Sbde cputime_overhead += cputime(); 14913107Sbde 15019000Sbde empty_loop(); 15119000Sbde startguprof(p); 15219000Sbde empty_loop(); 15319000Sbde empty_loop_time = cputime(); 15419000Sbde 15519000Sbde nullfunc_loop_profiled(); 15619000Sbde 15719000Sbde /* 15819000Sbde * Start profiling. There won't be any normal function calls since 15919000Sbde * interrupts are disabled, but we will call the profiling routines 16019000Sbde * directly to determine their overheads. 16119000Sbde */ 16219000Sbde p->state = GMON_PROF_HIRES; 16319000Sbde 16419000Sbde startguprof(p); 16519000Sbde nullfunc_loop_profiled(); 16619000Sbde 16719000Sbde startguprof(p); 16813107Sbde for (i = 0; i < CALIB_SCALE; i++) 16935596Sbde#if defined(__i386__) && __GNUC__ >= 2 17035210Sbde __asm("pushl %0; call __mcount; popl %%ecx" 17135210Sbde : 17235210Sbde : "i" (profil) 17335210Sbde : "ax", "bx", "cx", "dx", "memory"); 17413107Sbde#else 17513107Sbde#error 17613107Sbde#endif 17719000Sbde mcount_overhead = KCOUNT(p, PC_TO_I(p, profil)); 17813107Sbde 17919000Sbde startguprof(p); 18013107Sbde for (i = 0; i < CALIB_SCALE; i++) 18135596Sbde#if defined(__i386__) && __GNUC__ >= 2 18246548Sbde __asm("call " __XSTRING(HIDENAME(mexitcount)) "; 1:" 18335210Sbde : : : "ax", "bx", "cx", "dx", "memory"); 18435210Sbde __asm("movl $1b,%0" : "=rm" (tmp_addr)); 18513107Sbde#else 18613107Sbde#error 18713107Sbde#endif 18820396Sbde mexitcount_overhead = KCOUNT(p, PC_TO_I(p, tmp_addr)); 18913107Sbde 19013107Sbde p->state = GMON_PROF_OFF; 19119000Sbde stopguprof(p); 19219000Sbde 19374903Sjhb critical_exit(savecrit); 19413107Sbde 19519000Sbde nullfunc_loop_profiled_time = 0; 19637629Sbde for (tmp_addr = (uintfptr_t)nullfunc_loop_profiled; 19737629Sbde tmp_addr < (uintfptr_t)nullfunc_loop_profiled_end; 19820396Sbde tmp_addr += HISTFRACTION * sizeof(HISTCOUNTER)) 19920396Sbde nullfunc_loop_profiled_time += KCOUNT(p, PC_TO_I(p, tmp_addr)); 20019000Sbde#define CALIB_DOSCALE(count) (((count) + CALIB_SCALE / 3) / CALIB_SCALE) 20119000Sbde#define c2n(count, freq) ((int)((count) * 1000000000LL / freq)) 20219000Sbde printf("cputime %d, empty_loop %d, nullfunc_loop_profiled %d, mcount %d, mexitcount %d\n", 20319000Sbde CALIB_DOSCALE(c2n(cputime_overhead, p->profrate)), 20419000Sbde CALIB_DOSCALE(c2n(empty_loop_time, p->profrate)), 20519000Sbde CALIB_DOSCALE(c2n(nullfunc_loop_profiled_time, p->profrate)), 20619000Sbde CALIB_DOSCALE(c2n(mcount_overhead, p->profrate)), 20719000Sbde CALIB_DOSCALE(c2n(mexitcount_overhead, p->profrate))); 20819000Sbde cputime_overhead -= empty_loop_time; 20919000Sbde mcount_overhead -= empty_loop_time; 21019000Sbde mexitcount_overhead -= empty_loop_time; 21119000Sbde 21219000Sbde /*- 21319000Sbde * Profiling overheads are determined by the times between the 21419000Sbde * following events: 21519000Sbde * MC1: mcount() is called 21619000Sbde * MC2: cputime() (called from mcount()) latches the timer 21719000Sbde * MC3: mcount() completes 21819000Sbde * ME1: mexitcount() is called 21919000Sbde * ME2: cputime() (called from mexitcount()) latches the timer 22019000Sbde * ME3: mexitcount() completes. 22119000Sbde * The times between the events vary slightly depending on instruction 22219000Sbde * combination and cache misses, etc. Attempt to determine the 22319000Sbde * minimum times. These can be subtracted from the profiling times 22419000Sbde * without much risk of reducing the profiling times below what they 22519000Sbde * would be when profiling is not configured. Abbreviate: 22619000Sbde * ab = minimum time between MC1 and MC3 22719000Sbde * a = minumum time between MC1 and MC2 22819000Sbde * b = minimum time between MC2 and MC3 22919000Sbde * cd = minimum time between ME1 and ME3 23019000Sbde * c = minimum time between ME1 and ME2 23119000Sbde * d = minimum time between ME2 and ME3. 23219000Sbde * These satisfy the relations: 23319000Sbde * ab <= mcount_overhead (just measured) 23419000Sbde * a + b <= ab 23519000Sbde * cd <= mexitcount_overhead (just measured) 23619000Sbde * c + d <= cd 23719000Sbde * a + d <= nullfunc_loop_profiled_time (just measured) 23819000Sbde * a >= 0, b >= 0, c >= 0, d >= 0. 23919000Sbde * Assume that ab and cd are equal to the minimums. 24019000Sbde */ 24119000Sbde p->cputime_overhead = CALIB_DOSCALE(cputime_overhead); 24219000Sbde p->mcount_overhead = CALIB_DOSCALE(mcount_overhead - cputime_overhead); 24319000Sbde p->mexitcount_overhead = CALIB_DOSCALE(mexitcount_overhead 24419000Sbde - cputime_overhead); 24519000Sbde nullfunc_loop_overhead = nullfunc_loop_profiled_time - empty_loop_time; 24619000Sbde p->mexitcount_post_overhead = CALIB_DOSCALE((mcount_overhead 24719000Sbde - nullfunc_loop_overhead) 24819000Sbde / 4); 24919000Sbde p->mexitcount_pre_overhead = p->mexitcount_overhead 25019000Sbde + p->cputime_overhead 25119000Sbde - p->mexitcount_post_overhead; 25219000Sbde p->mcount_pre_overhead = CALIB_DOSCALE(nullfunc_loop_overhead) 25319000Sbde - p->mexitcount_post_overhead; 25419000Sbde p->mcount_post_overhead = p->mcount_overhead 25519000Sbde + p->cputime_overhead 25619000Sbde - p->mcount_pre_overhead; 25719000Sbde printf( 25819000Sbde"Profiling overheads: mcount: %d+%d, %d+%d; mexitcount: %d+%d, %d+%d nsec\n", 25919000Sbde c2n(p->cputime_overhead, p->profrate), 26019000Sbde c2n(p->mcount_overhead, p->profrate), 26119000Sbde c2n(p->mcount_pre_overhead, p->profrate), 26219000Sbde c2n(p->mcount_post_overhead, p->profrate), 26319000Sbde c2n(p->cputime_overhead, p->profrate), 26419000Sbde c2n(p->mexitcount_overhead, p->profrate), 26519000Sbde c2n(p->mexitcount_pre_overhead, p->profrate), 26619000Sbde c2n(p->mexitcount_post_overhead, p->profrate)); 26719000Sbde printf( 26819000Sbde"Profiling overheads: mcount: %d+%d, %d+%d; mexitcount: %d+%d, %d+%d cycles\n", 26919000Sbde p->cputime_overhead, p->mcount_overhead, 27019000Sbde p->mcount_pre_overhead, p->mcount_post_overhead, 27119000Sbde p->cputime_overhead, p->mexitcount_overhead, 27219000Sbde p->mexitcount_pre_overhead, p->mexitcount_post_overhead); 27313107Sbde#endif /* GUPROF */ 2741541Srgrimes} 2751541Srgrimes 2761541Srgrimes/* 2771541Srgrimes * Return kernel profiling information. 2781541Srgrimes */ 27912429Sphkstatic int 28062573Sphksysctl_kern_prof(SYSCTL_HANDLER_ARGS) 2811541Srgrimes{ 28212429Sphk int *name = (int *) arg1; 28312429Sphk u_int namelen = arg2; 2841541Srgrimes struct gmonparam *gp = &_gmonparam; 2851541Srgrimes int error; 28613107Sbde int state; 2871541Srgrimes 2881541Srgrimes /* all sysctl names at this level are terminal */ 2891541Srgrimes if (namelen != 1) 2901541Srgrimes return (ENOTDIR); /* overloaded */ 2911541Srgrimes 2921541Srgrimes switch (name[0]) { 2931541Srgrimes case GPROF_STATE: 29413107Sbde state = gp->state; 29513107Sbde error = sysctl_handle_int(oidp, &state, 0, req); 2961541Srgrimes if (error) 2971541Srgrimes return (error); 29813107Sbde if (!req->newptr) 29913107Sbde return (0); 30013107Sbde if (state == GMON_PROF_OFF) { 30119000Sbde gp->state = state; 3021541Srgrimes stopprofclock(&proc0); 30319000Sbde stopguprof(gp); 30413107Sbde } else if (state == GMON_PROF_ON) { 30519000Sbde gp->state = GMON_PROF_OFF; 30619000Sbde stopguprof(gp); 30713107Sbde gp->profrate = profhz; 30819000Sbde startprofclock(&proc0); 30913107Sbde gp->state = state; 31013107Sbde#ifdef GUPROF 31113107Sbde } else if (state == GMON_PROF_HIRES) { 31219000Sbde gp->state = GMON_PROF_OFF; 31313107Sbde stopprofclock(&proc0); 31419000Sbde startguprof(gp); 31513107Sbde gp->state = state; 31613107Sbde#endif 31713107Sbde } else if (state != gp->state) 31813107Sbde return (EINVAL); 3191541Srgrimes return (0); 3201541Srgrimes case GPROF_COUNT: 32112429Sphk return (sysctl_handle_opaque(oidp, 32212429Sphk gp->kcount, gp->kcountsize, req)); 3231541Srgrimes case GPROF_FROMS: 32412429Sphk return (sysctl_handle_opaque(oidp, 32512429Sphk gp->froms, gp->fromssize, req)); 3261541Srgrimes case GPROF_TOS: 32712429Sphk return (sysctl_handle_opaque(oidp, 32812429Sphk gp->tos, gp->tossize, req)); 3291541Srgrimes case GPROF_GMONPARAM: 33012429Sphk return (sysctl_handle_opaque(oidp, gp, sizeof *gp, req)); 3311541Srgrimes default: 3321541Srgrimes return (EOPNOTSUPP); 3331541Srgrimes } 3341541Srgrimes /* NOTREACHED */ 3351541Srgrimes} 33612429Sphk 33712429SphkSYSCTL_NODE(_kern, KERN_PROF, prof, CTLFLAG_RW, sysctl_kern_prof, ""); 3381541Srgrimes#endif /* GPROF */ 3391541Srgrimes 3401541Srgrimes/* 3411541Srgrimes * Profiling system call. 3421541Srgrimes * 3431541Srgrimes * The scale factor is a fixed point number with 16 bits of fraction, so that 3441541Srgrimes * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 3451541Srgrimes */ 34612221Sbde#ifndef _SYS_SYSPROTO_H_ 3471541Srgrimesstruct profil_args { 3481541Srgrimes caddr_t samples; 34938864Sbde size_t size; 35038864Sbde size_t offset; 3511541Srgrimes u_int scale; 3521541Srgrimes}; 35312221Sbde#endif 35482717Sdillon/* 35582717Sdillon * MPSAFE 35682717Sdillon */ 3571541Srgrimes/* ARGSUSED */ 3581549Srgrimesint 35930994Sphkprofil(p, uap) 3601541Srgrimes struct proc *p; 3611541Srgrimes register struct profil_args *uap; 3621541Srgrimes{ 3631541Srgrimes register struct uprof *upp; 3641541Srgrimes int s; 36582717Sdillon int error = 0; 3661541Srgrimes 36782717Sdillon mtx_lock(&Giant); 36882717Sdillon 36982717Sdillon if (uap->scale > (1 << 16)) { 37082717Sdillon error = EINVAL; 37182717Sdillon goto done2; 37282717Sdillon } 3731541Srgrimes if (uap->scale == 0) { 3741541Srgrimes stopprofclock(p); 37582717Sdillon goto done2; 3761541Srgrimes } 3771541Srgrimes upp = &p->p_stats->p_prof; 3781541Srgrimes 3791541Srgrimes /* Block profile interrupts while changing state. */ 3801541Srgrimes s = splstatclock(); 3811541Srgrimes upp->pr_off = uap->offset; 3821541Srgrimes upp->pr_scale = uap->scale; 3831541Srgrimes upp->pr_base = uap->samples; 3841541Srgrimes upp->pr_size = uap->size; 3851541Srgrimes startprofclock(p); 3861541Srgrimes splx(s); 3871541Srgrimes 38882717Sdillondone2: 38982717Sdillon mtx_unlock(&Giant); 39082717Sdillon return (error); 3911541Srgrimes} 3921541Srgrimes 3931541Srgrimes/* 3941541Srgrimes * Scale is a fixed-point number with the binary point 16 bits 3951541Srgrimes * into the value, and is <= 1.0. pc is at most 32 bits, so the 3961541Srgrimes * intermediate result is at most 48 bits. 3971541Srgrimes */ 3981541Srgrimes#define PC_TO_INDEX(pc, prof) \ 3991541Srgrimes ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 4001541Srgrimes (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 4011541Srgrimes 4021541Srgrimes/* 4031541Srgrimes * Collect user-level profiling statistics; called on a profiling tick, 4041541Srgrimes * when a process is running in user-mode. This routine may be called 4051541Srgrimes * from an interrupt context. We try to update the user profiling buffers 4061541Srgrimes * cheaply with fuswintr() and suswintr(). If that fails, we revert to 4071541Srgrimes * an AST that will vector us to trap() with a context in which copyin 4081541Srgrimes * and copyout will work. Trap will then call addupc_task(). 4091541Srgrimes * 4101541Srgrimes * Note that we may (rarely) not get around to the AST soon enough, and 4111541Srgrimes * lose profile ticks when the next tick overwrites this one, but in this 4121541Srgrimes * case the system is overloaded and the profile is probably already 4131541Srgrimes * inaccurate. 4141541Srgrimes */ 4151541Srgrimesvoid 4161541Srgrimesaddupc_intr(p, pc, ticks) 4171541Srgrimes register struct proc *p; 41872912Sjhb register uintptr_t pc; 4191541Srgrimes u_int ticks; 4201541Srgrimes{ 4211541Srgrimes register struct uprof *prof; 4221541Srgrimes register caddr_t addr; 4231541Srgrimes register u_int i; 4241541Srgrimes register int v; 4251541Srgrimes 4261541Srgrimes if (ticks == 0) 4271541Srgrimes return; 4281541Srgrimes prof = &p->p_stats->p_prof; 4291541Srgrimes if (pc < prof->pr_off || 4301541Srgrimes (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 4311541Srgrimes return; /* out of range; ignore */ 4321541Srgrimes 4331541Srgrimes addr = prof->pr_base + i; 4341541Srgrimes if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + ticks) == -1) { 43581493Sjhb mtx_lock_spin(&sched_lock); 4361541Srgrimes prof->pr_addr = pc; 4371541Srgrimes prof->pr_ticks = ticks; 43881493Sjhb p->p_sflag |= PS_OWEUPC | PS_ASTPENDING; 43981493Sjhb mtx_unlock_spin(&sched_lock); 4401541Srgrimes } 4411541Srgrimes} 4421541Srgrimes 4431541Srgrimes/* 4441541Srgrimes * Much like before, but we can afford to take faults here. If the 4451541Srgrimes * update fails, we simply turn off profiling. 4461541Srgrimes */ 44713017Sbdevoid 4481541Srgrimesaddupc_task(p, pc, ticks) 4491541Srgrimes register struct proc *p; 45072912Sjhb register uintptr_t pc; 4511541Srgrimes u_int ticks; 4521541Srgrimes{ 4531541Srgrimes register struct uprof *prof; 4541541Srgrimes register caddr_t addr; 4551541Srgrimes register u_int i; 4561541Srgrimes u_short v; 4571541Srgrimes 45871565Sjhb /* Testing PS_PROFIL may be unnecessary, but is certainly safe. */ 45977840Sjhb if ((p->p_sflag & PS_PROFIL) == 0 || ticks == 0) 4601541Srgrimes return; 4611541Srgrimes 4621541Srgrimes prof = &p->p_stats->p_prof; 4631541Srgrimes if (pc < prof->pr_off || 4641541Srgrimes (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 4651541Srgrimes return; 4661541Srgrimes 4671541Srgrimes addr = prof->pr_base + i; 4681541Srgrimes if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) { 4691541Srgrimes v += ticks; 4701541Srgrimes if (copyout((caddr_t)&v, addr, sizeof(v)) == 0) 4711541Srgrimes return; 4721541Srgrimes } 4731541Srgrimes stopprofclock(p); 4741541Srgrimes} 475