Function kmstartup

freebsd/kern/subr_prof.c:141–320

}

static void
kmstartup(void *dummy)
{
	char *cp;
	struct gmonparam *p = &_gmonparam;
#ifdef GUPROF
	int cputime_overhead;
	int empty_loop_time;
	int i;
	int mcount_overhead;
	int mexitcount_overhead;
	int nullfunc_loop_overhead;
	int nullfunc_loop_profiled_time;
	uintfptr_t tmp_addr;
#endif

	/*
	 * Round lowpc and highpc to multiples of the density we're using
	 * so the rest of the scaling (here and in gprof) stays in ints.
	 */
	p->lowpc = ROUNDDOWN((u_long)btext, HISTFRACTION * sizeof(HISTCOUNTER));
	p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER));
	p->textsize = p->highpc - p->lowpc;
	printf("Profiling kernel, textsize=%lu [%jx..%jx]\n",
	    p->textsize, (uintmax_t)p->lowpc, (uintmax_t)p->highpc);
	p->kcountsize = p->textsize / HISTFRACTION;
	p->hashfraction = HASHFRACTION;
	p->fromssize = p->textsize / HASHFRACTION;
	p->tolimit = p->textsize * ARCDENSITY / 100;
	if (p->tolimit < MINARCS)
		p->tolimit = MINARCS;
	else if (p->tolimit > MAXARCS)
		p->tolimit = MAXARCS;
	p->tossize = p->tolimit * sizeof(struct tostruct);
	cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize,
	    M_GPROF, M_WAITOK | M_ZERO);
	p->tos = (struct tostruct *)cp;
	cp += p->tossize;
	p->kcount = (HISTCOUNTER *)cp;
	cp += p->kcountsize;
	p->froms = (u_short *)cp;
	p->histcounter_type = FUNCTION_ALIGNMENT / HISTFRACTION * NBBY;

#ifdef GUPROF
	/* Signed counters. */
	p->histcounter_type = -p->histcounter_type;

	/* Initialize pointers to overhead counters. */
	p->cputime_count = &KCOUNT(p, PC_TO_I(p, cputime));
	p->mcount_count = &KCOUNT(p, PC_TO_I(p, mcount));
	p->mexitcount_count = &KCOUNT(p, PC_TO_I(p, mexitcount));

	/*
	 * Disable interrupts to avoid interference while we calibrate
	 * things.
	 */
	critical_enter();