threatened in rev.1.10 of usr.sbin/kgmon/kgmon.c more than 2 years ago. kgmon has been recovering from the missing initialization for too long, but the fixup there is ifdefed for i386's and shouldn't be needed for other arches.
582 lines
17 KiB
C
582 lines
17 KiB
C
/*-
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* Copyright (c) 1982, 1986, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)subr_prof.c 8.3 (Berkeley) 9/23/93
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/sysproto.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/resourcevar.h>
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#include <sys/sysctl.h>
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#include <machine/cpu.h>
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#ifdef GPROF
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#include <sys/malloc.h>
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#include <sys/gmon.h>
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#undef MCOUNT
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static MALLOC_DEFINE(M_GPROF, "gprof", "kernel profiling buffer");
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static void kmstartup(void *);
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SYSINIT(kmem, SI_SUB_KPROF, SI_ORDER_FIRST, kmstartup, NULL)
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struct gmonparam _gmonparam = { GMON_PROF_OFF };
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#ifdef GUPROF
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void
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nullfunc_loop_profiled()
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{
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int i;
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for (i = 0; i < CALIB_SCALE; i++)
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nullfunc_profiled();
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}
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#define nullfunc_loop_profiled_end nullfunc_profiled /* XXX */
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void
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nullfunc_profiled()
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{
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}
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#endif /* GUPROF */
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/*
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* Update the histograms to support extending the text region arbitrarily.
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* This is done slightly naively (no sparse regions), so will waste slight
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* amounts of memory, but will overall work nicely enough to allow profiling
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* of KLDs.
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*/
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void
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kmupetext(uintfptr_t nhighpc)
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{
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struct gmonparam np; /* slightly large */
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struct gmonparam *p = &_gmonparam;
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char *cp;
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GIANT_REQUIRED;
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bcopy(p, &np, sizeof(*p));
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np.highpc = ROUNDUP(nhighpc, HISTFRACTION * sizeof(HISTCOUNTER));
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if (np.highpc <= p->highpc)
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return;
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np.textsize = np.highpc - p->lowpc;
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np.kcountsize = np.textsize / HISTFRACTION;
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np.hashfraction = HASHFRACTION;
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np.fromssize = np.textsize / HASHFRACTION;
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np.tolimit = np.textsize * ARCDENSITY / 100;
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if (np.tolimit < MINARCS)
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np.tolimit = MINARCS;
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else if (np.tolimit > MAXARCS)
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np.tolimit = MAXARCS;
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np.tossize = np.tolimit * sizeof(struct tostruct);
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cp = malloc(np.kcountsize + np.fromssize + np.tossize,
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M_GPROF, M_WAITOK);
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/*
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* Check for something else extending highpc while we slept.
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*/
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if (np.highpc <= p->highpc) {
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free(cp, M_GPROF);
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return;
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}
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np.tos = (struct tostruct *)cp;
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cp += np.tossize;
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np.kcount = (HISTCOUNTER *)cp;
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cp += np.kcountsize;
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np.froms = (u_short *)cp;
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#ifdef GUPROF
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/* Reinitialize pointers to overhead counters. */
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np.cputime_count = &KCOUNT(&np, PC_TO_I(&np, cputime));
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np.mcount_count = &KCOUNT(&np, PC_TO_I(&np, mcount));
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np.mexitcount_count = &KCOUNT(&np, PC_TO_I(&np, mexitcount));
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#endif
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critical_enter();
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bcopy(p->tos, np.tos, p->tossize);
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bzero((char *)np.tos + p->tossize, np.tossize - p->tossize);
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bcopy(p->kcount, np.kcount, p->kcountsize);
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bzero((char *)np.kcount + p->kcountsize, np.kcountsize -
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p->kcountsize);
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bcopy(p->froms, np.froms, p->fromssize);
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bzero((char *)np.froms + p->fromssize, np.fromssize - p->fromssize);
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cp = (char *)p->tos;
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bcopy(&np, p, sizeof(*p));
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critical_exit();
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free(cp, M_GPROF);
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}
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static void
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kmstartup(dummy)
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void *dummy;
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{
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char *cp;
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struct gmonparam *p = &_gmonparam;
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#ifdef GUPROF
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int cputime_overhead;
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int empty_loop_time;
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int i;
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int mcount_overhead;
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int mexitcount_overhead;
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int nullfunc_loop_overhead;
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int nullfunc_loop_profiled_time;
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uintfptr_t tmp_addr;
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#endif
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/*
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* Round lowpc and highpc to multiples of the density we're using
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* so the rest of the scaling (here and in gprof) stays in ints.
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*/
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p->lowpc = ROUNDDOWN((u_long)btext, HISTFRACTION * sizeof(HISTCOUNTER));
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p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER));
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p->textsize = p->highpc - p->lowpc;
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printf("Profiling kernel, textsize=%lu [%x..%x]\n",
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p->textsize, p->lowpc, p->highpc);
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p->kcountsize = p->textsize / HISTFRACTION;
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p->hashfraction = HASHFRACTION;
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p->fromssize = p->textsize / HASHFRACTION;
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p->tolimit = p->textsize * ARCDENSITY / 100;
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if (p->tolimit < MINARCS)
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p->tolimit = MINARCS;
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else if (p->tolimit > MAXARCS)
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p->tolimit = MAXARCS;
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p->tossize = p->tolimit * sizeof(struct tostruct);
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cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize,
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M_GPROF, M_WAITOK | M_ZERO);
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p->tos = (struct tostruct *)cp;
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cp += p->tossize;
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p->kcount = (HISTCOUNTER *)cp;
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cp += p->kcountsize;
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p->froms = (u_short *)cp;
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p->histcounter_type = FUNCTION_ALIGNMENT / HISTFRACTION * NBBY;
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#ifdef GUPROF
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/* Signed counters. */
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p->histcounter_type = -p->histcounter_type;
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/* Initialize pointers to overhead counters. */
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p->cputime_count = &KCOUNT(p, PC_TO_I(p, cputime));
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p->mcount_count = &KCOUNT(p, PC_TO_I(p, mcount));
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p->mexitcount_count = &KCOUNT(p, PC_TO_I(p, mexitcount));
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/*
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* Disable interrupts to avoid interference while we calibrate
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* things.
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*/
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critical_enter();
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/*
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* Determine overheads.
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* XXX this needs to be repeated for each useful timer/counter.
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*/
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cputime_overhead = 0;
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startguprof(p);
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for (i = 0; i < CALIB_SCALE; i++)
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cputime_overhead += cputime();
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empty_loop();
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startguprof(p);
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empty_loop();
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empty_loop_time = cputime();
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nullfunc_loop_profiled();
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/*
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* Start profiling. There won't be any normal function calls since
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* interrupts are disabled, but we will call the profiling routines
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* directly to determine their overheads.
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*/
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p->state = GMON_PROF_HIRES;
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startguprof(p);
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nullfunc_loop_profiled();
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startguprof(p);
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for (i = 0; i < CALIB_SCALE; i++)
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MCOUNT_OVERHEAD(profil);
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mcount_overhead = KCOUNT(p, PC_TO_I(p, profil));
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startguprof(p);
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for (i = 0; i < CALIB_SCALE; i++)
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MEXITCOUNT_OVERHEAD();
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MEXITCOUNT_OVERHEAD_GETLABEL(tmp_addr);
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mexitcount_overhead = KCOUNT(p, PC_TO_I(p, tmp_addr));
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p->state = GMON_PROF_OFF;
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stopguprof(p);
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critical_exit();
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nullfunc_loop_profiled_time = 0;
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for (tmp_addr = (uintfptr_t)nullfunc_loop_profiled;
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tmp_addr < (uintfptr_t)nullfunc_loop_profiled_end;
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tmp_addr += HISTFRACTION * sizeof(HISTCOUNTER))
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nullfunc_loop_profiled_time += KCOUNT(p, PC_TO_I(p, tmp_addr));
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#define CALIB_DOSCALE(count) (((count) + CALIB_SCALE / 3) / CALIB_SCALE)
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#define c2n(count, freq) ((int)((count) * 1000000000LL / freq))
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printf("cputime %d, empty_loop %d, nullfunc_loop_profiled %d, mcount %d, mexitcount %d\n",
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CALIB_DOSCALE(c2n(cputime_overhead, p->profrate)),
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CALIB_DOSCALE(c2n(empty_loop_time, p->profrate)),
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CALIB_DOSCALE(c2n(nullfunc_loop_profiled_time, p->profrate)),
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CALIB_DOSCALE(c2n(mcount_overhead, p->profrate)),
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CALIB_DOSCALE(c2n(mexitcount_overhead, p->profrate)));
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cputime_overhead -= empty_loop_time;
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mcount_overhead -= empty_loop_time;
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mexitcount_overhead -= empty_loop_time;
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/*-
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* Profiling overheads are determined by the times between the
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* following events:
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* MC1: mcount() is called
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* MC2: cputime() (called from mcount()) latches the timer
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* MC3: mcount() completes
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* ME1: mexitcount() is called
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* ME2: cputime() (called from mexitcount()) latches the timer
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* ME3: mexitcount() completes.
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* The times between the events vary slightly depending on instruction
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* combination and cache misses, etc. Attempt to determine the
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* minimum times. These can be subtracted from the profiling times
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* without much risk of reducing the profiling times below what they
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* would be when profiling is not configured. Abbreviate:
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* ab = minimum time between MC1 and MC3
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* a = minumum time between MC1 and MC2
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* b = minimum time between MC2 and MC3
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* cd = minimum time between ME1 and ME3
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* c = minimum time between ME1 and ME2
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* d = minimum time between ME2 and ME3.
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* These satisfy the relations:
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* ab <= mcount_overhead (just measured)
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* a + b <= ab
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* cd <= mexitcount_overhead (just measured)
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* c + d <= cd
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* a + d <= nullfunc_loop_profiled_time (just measured)
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* a >= 0, b >= 0, c >= 0, d >= 0.
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* Assume that ab and cd are equal to the minimums.
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*/
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p->cputime_overhead = CALIB_DOSCALE(cputime_overhead);
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p->mcount_overhead = CALIB_DOSCALE(mcount_overhead - cputime_overhead);
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p->mexitcount_overhead = CALIB_DOSCALE(mexitcount_overhead
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- cputime_overhead);
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nullfunc_loop_overhead = nullfunc_loop_profiled_time - empty_loop_time;
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p->mexitcount_post_overhead = CALIB_DOSCALE((mcount_overhead
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- nullfunc_loop_overhead)
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/ 4);
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p->mexitcount_pre_overhead = p->mexitcount_overhead
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+ p->cputime_overhead
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- p->mexitcount_post_overhead;
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p->mcount_pre_overhead = CALIB_DOSCALE(nullfunc_loop_overhead)
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- p->mexitcount_post_overhead;
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p->mcount_post_overhead = p->mcount_overhead
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+ p->cputime_overhead
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- p->mcount_pre_overhead;
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printf(
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"Profiling overheads: mcount: %d+%d, %d+%d; mexitcount: %d+%d, %d+%d nsec\n",
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c2n(p->cputime_overhead, p->profrate),
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c2n(p->mcount_overhead, p->profrate),
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c2n(p->mcount_pre_overhead, p->profrate),
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c2n(p->mcount_post_overhead, p->profrate),
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c2n(p->cputime_overhead, p->profrate),
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c2n(p->mexitcount_overhead, p->profrate),
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c2n(p->mexitcount_pre_overhead, p->profrate),
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c2n(p->mexitcount_post_overhead, p->profrate));
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printf(
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"Profiling overheads: mcount: %d+%d, %d+%d; mexitcount: %d+%d, %d+%d cycles\n",
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p->cputime_overhead, p->mcount_overhead,
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p->mcount_pre_overhead, p->mcount_post_overhead,
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p->cputime_overhead, p->mexitcount_overhead,
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p->mexitcount_pre_overhead, p->mexitcount_post_overhead);
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#endif /* GUPROF */
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}
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/*
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* Return kernel profiling information.
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*/
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static int
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sysctl_kern_prof(SYSCTL_HANDLER_ARGS)
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{
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int *name = (int *) arg1;
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u_int namelen = arg2;
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struct gmonparam *gp = &_gmonparam;
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int error;
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int state;
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/* all sysctl names at this level are terminal */
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if (namelen != 1)
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return (ENOTDIR); /* overloaded */
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switch (name[0]) {
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case GPROF_STATE:
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state = gp->state;
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error = sysctl_handle_int(oidp, &state, 0, req);
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if (error)
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return (error);
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if (!req->newptr)
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return (0);
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if (state == GMON_PROF_OFF) {
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gp->state = state;
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PROC_LOCK(&proc0);
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stopprofclock(&proc0);
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PROC_UNLOCK(&proc0);
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stopguprof(gp);
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} else if (state == GMON_PROF_ON) {
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gp->state = GMON_PROF_OFF;
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stopguprof(gp);
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gp->profrate = profhz;
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PROC_LOCK(&proc0);
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startprofclock(&proc0);
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PROC_UNLOCK(&proc0);
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gp->state = state;
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#ifdef GUPROF
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} else if (state == GMON_PROF_HIRES) {
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gp->state = GMON_PROF_OFF;
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PROC_LOCK(&proc0);
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stopprofclock(&proc0);
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PROC_UNLOCK(&proc0);
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startguprof(gp);
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gp->state = state;
|
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#endif
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} else if (state != gp->state)
|
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return (EINVAL);
|
|
return (0);
|
|
case GPROF_COUNT:
|
|
return (sysctl_handle_opaque(oidp,
|
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gp->kcount, gp->kcountsize, req));
|
|
case GPROF_FROMS:
|
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return (sysctl_handle_opaque(oidp,
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|
gp->froms, gp->fromssize, req));
|
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case GPROF_TOS:
|
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return (sysctl_handle_opaque(oidp,
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gp->tos, gp->tossize, req));
|
|
case GPROF_GMONPARAM:
|
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return (sysctl_handle_opaque(oidp, gp, sizeof *gp, req));
|
|
default:
|
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return (EOPNOTSUPP);
|
|
}
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
SYSCTL_NODE(_kern, KERN_PROF, prof, CTLFLAG_RW, sysctl_kern_prof, "");
|
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#endif /* GPROF */
|
|
|
|
/*
|
|
* Profiling system call.
|
|
*
|
|
* The scale factor is a fixed point number with 16 bits of fraction, so that
|
|
* 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling.
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct profil_args {
|
|
caddr_t samples;
|
|
size_t size;
|
|
size_t offset;
|
|
u_int scale;
|
|
};
|
|
#endif
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
/* ARGSUSED */
|
|
int
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|
profil(td, uap)
|
|
struct thread *td;
|
|
register struct profil_args *uap;
|
|
{
|
|
struct uprof *upp;
|
|
struct proc *p;
|
|
|
|
if (uap->scale > (1 << 16))
|
|
return (EINVAL);
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|
|
|
p = td->td_proc;
|
|
if (uap->scale == 0) {
|
|
PROC_LOCK(td->td_proc);
|
|
stopprofclock(td->td_proc);
|
|
PROC_UNLOCK(td->td_proc);
|
|
return (0);
|
|
}
|
|
upp = &td->td_proc->p_stats->p_prof;
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upp->pr_off = uap->offset;
|
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upp->pr_scale = uap->scale;
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upp->pr_base = uap->samples;
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upp->pr_size = uap->size;
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PROC_LOCK(p);
|
|
startprofclock(p);
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|
PROC_UNLOCK(p);
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Scale is a fixed-point number with the binary point 16 bits
|
|
* into the value, and is <= 1.0. pc is at most 32 bits, so the
|
|
* intermediate result is at most 48 bits.
|
|
*/
|
|
#define PC_TO_INDEX(pc, prof) \
|
|
((int)(((u_quad_t)((pc) - (prof)->pr_off) * \
|
|
(u_quad_t)((prof)->pr_scale)) >> 16) & ~1)
|
|
|
|
/*
|
|
* Collect user-level profiling statistics; called on a profiling tick,
|
|
* when a process is running in user-mode. This routine may be called
|
|
* from an interrupt context. We try to update the user profiling buffers
|
|
* cheaply with fuswintr() and suswintr(). If that fails, we revert to
|
|
* an AST that will vector us to trap() with a context in which copyin
|
|
* and copyout will work. Trap will then call addupc_task().
|
|
*
|
|
* Note that we may (rarely) not get around to the AST soon enough, and
|
|
* lose profile ticks when the next tick overwrites this one, but in this
|
|
* case the system is overloaded and the profile is probably already
|
|
* inaccurate.
|
|
*/
|
|
void
|
|
addupc_intr(struct thread *td, uintptr_t pc, u_int ticks)
|
|
{
|
|
struct uprof *prof;
|
|
caddr_t addr;
|
|
u_int i;
|
|
int v;
|
|
|
|
if (ticks == 0)
|
|
return;
|
|
prof = &td->td_proc->p_stats->p_prof;
|
|
if (pc < prof->pr_off ||
|
|
(i = PC_TO_INDEX(pc, prof)) >= prof->pr_size)
|
|
return; /* out of range; ignore */
|
|
|
|
addr = prof->pr_base + i;
|
|
if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + ticks) == -1) {
|
|
mtx_lock_spin(&sched_lock);
|
|
prof->pr_addr = pc;
|
|
prof->pr_ticks = ticks;
|
|
td->td_flags |= TDF_OWEUPC | TDF_ASTPENDING ;
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Much like before, but we can afford to take faults here. If the
|
|
* update fails, we simply turn off profiling.
|
|
*/
|
|
void
|
|
addupc_task(struct thread *td, uintptr_t pc, u_int ticks)
|
|
{
|
|
struct proc *p = td->td_proc;
|
|
struct uprof *prof;
|
|
caddr_t addr;
|
|
u_int i;
|
|
u_short v;
|
|
int stop = 0;
|
|
|
|
if (ticks == 0)
|
|
return;
|
|
|
|
PROC_LOCK(p);
|
|
if (!(p->p_flag & P_PROFIL)) {
|
|
PROC_UNLOCK(p);
|
|
return;
|
|
}
|
|
p->p_profthreads++;
|
|
PROC_UNLOCK(p);
|
|
prof = &p->p_stats->p_prof;
|
|
if (pc < prof->pr_off ||
|
|
(i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) {
|
|
goto out;
|
|
}
|
|
|
|
addr = prof->pr_base + i;
|
|
if (copyin(addr, &v, sizeof(v)) == 0) {
|
|
v += ticks;
|
|
if (copyout(&v, addr, sizeof(v)) == 0)
|
|
goto out;
|
|
}
|
|
stop = 1;
|
|
|
|
out:
|
|
PROC_LOCK(p);
|
|
if (--p->p_profthreads == 0) {
|
|
if (p->p_flag & P_STOPPROF) {
|
|
wakeup(&p->p_profthreads);
|
|
stop = 0;
|
|
}
|
|
}
|
|
if (stop)
|
|
stopprofclock(p);
|
|
PROC_UNLOCK(p);
|
|
}
|
|
|
|
#if defined(__i386__) && __GNUC__ >= 2 && !defined(__INTEL_COMPILER)
|
|
/*
|
|
* Support for "--test-coverage --profile-arcs" in GCC.
|
|
*
|
|
* We need to call all the functions in the .ctor section, in order
|
|
* to get all the counter-arrays strung into a list.
|
|
*
|
|
* XXX: the .ctors call __bb_init_func which is located in over in
|
|
* XXX: i386/i386/support.s for historical reasons. There is probably
|
|
* XXX: no reason for that to be assembler anymore, but doing it right
|
|
* XXX: in MI C code requires one to reverse-engineer the type-selection
|
|
* XXX: inside GCC. Have fun.
|
|
*
|
|
* XXX: Worrisome perspective: Calling the .ctors may make C++ in the
|
|
* XXX: kernel feasible. Don't.
|
|
*/
|
|
typedef void (*ctor_t)(void);
|
|
extern ctor_t _start_ctors, _stop_ctors;
|
|
|
|
static void
|
|
tcov_init(void *foo __unused)
|
|
{
|
|
ctor_t *p, q;
|
|
|
|
for (p = &_start_ctors; p < &_stop_ctors; p++) {
|
|
q = *p;
|
|
q();
|
|
}
|
|
}
|
|
|
|
SYSINIT(tcov_init, SI_SUB_KPROF, SI_ORDER_SECOND, tcov_init, NULL)
|
|
|
|
/*
|
|
* GCC contains magic to recognize calls to for instance execve() and
|
|
* puts in calls to this function to preserve the profile counters.
|
|
* XXX: Put zinging punchline here.
|
|
*/
|
|
void __bb_fork_func(void);
|
|
void
|
|
__bb_fork_func(void)
|
|
{
|
|
}
|
|
|
|
#endif
|
|
|