xref: /csrg-svn/sys/kern/subr_prof.c (revision 17094)

/*	subr_prof.c	6.4	84/08/29	*/

/* last integrated from: gmon.c	4.10 (Berkeley) 1/14/83 */

#ifdef GPROF
#include "gprof.h"
#include "param.h"
#include "systm.h"

/*
 * Froms is actually a bunch of unsigned shorts indexing tos
 */
int profiling = 3;
u_short *froms;
struct tostruct *tos = 0;
long tolimit = 0;
#ifdef vax
char	*s_lowpc = (char *)0x80000000;
#endif
extern char etext;
char *s_highpc = &etext;
u_long	s_textsize = 0;
int ssiz;
u_short	*sbuf;
u_short	*kcount;

kmstartup()
{
	u_long	fromssize, tossize;

	/*
	 *	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.
	 */
	s_lowpc = (char *)
	    ROUNDDOWN((unsigned)s_lowpc, HISTFRACTION*sizeof(HISTCOUNTER));
	s_highpc = (char *)
	    ROUNDUP((unsigned)s_highpc, HISTFRACTION*sizeof(HISTCOUNTER));
	s_textsize = s_highpc - s_lowpc;
	printf("Profiling kernel, s_textsize=%d [%x..%x]\n",
		s_textsize, s_lowpc, s_highpc);
	ssiz = (s_textsize / HISTFRACTION) + sizeof(struct phdr);
	sbuf = (u_short *)calloc(ssiz);
	if (sbuf == 0) {
		printf("No space for monitor buffer(s)\n");
		return;
	}
	blkclr((caddr_t)sbuf, ssiz);
	fromssize = s_textsize / HASHFRACTION;
	froms = (u_short *)calloc(fromssize);
	if (froms == 0) {
		printf("No space for monitor buffer(s)\n");
		cfreemem(sbuf, ssiz);
		sbuf = 0;
		return;
	}
	blkclr((caddr_t)froms, fromssize);
	tolimit = s_textsize * ARCDENSITY / 100;
	if (tolimit < MINARCS) {
		tolimit = MINARCS;
	} else if (tolimit > 65534) {
		tolimit = 65534;
	}
	tossize = tolimit * sizeof(struct tostruct);
	tos = (struct tostruct *)calloc(tossize);
	if (tos == 0) {
		printf("No space for monitor buffer(s)\n");
		cfreemem(sbuf, ssiz);
		sbuf = 0;
		cfreemem(froms, fromssize);
		froms = 0;
		return;
	}
	blkclr((caddr_t)tos, tossize);
	tos[0].link = 0;
	((struct phdr *)sbuf)->lpc = s_lowpc;
	((struct phdr *)sbuf)->hpc = s_highpc;
	((struct phdr *)sbuf)->ncnt = ssiz;
	kcount = (u_short *)(((int)sbuf) + sizeof(struct phdr));
#ifdef notdef
	/*
	 *	profiling is what mcount checks to see if
	 *	all the data structures are ready!!!
	 */
	profiling = 0;		/* patch by hand when you're ready */
#endif
}

#ifdef vax
/*
 * This routine is massaged so that it may be jsb'ed to
 */
asm(".text");
asm("#the beginning of mcount()");
asm(".data");
mcount()
{
	register char			*selfpc;	/* r11 => r5 */
	register unsigned short		*frompcindex;	/* r10 => r4 */
	register struct tostruct	*top;		/* r9  => r3 */
	register struct tostruct	*prevtop;	/* r8  => r2 */
	register long			toindex;	/* r7  => r1 */
	static int s;

#ifdef lint
	selfpc = (char *)0;
	frompcindex = 0;
#else not lint
	/*
	 *	find the return address for mcount,
	 *	and the return address for mcount's caller.
	 */
	asm("	.text");		/* make sure we're in text space */
	asm("	movl (sp), r11");	/* selfpc = ... (jsb frame) */
	asm("	movl 16(fp), r10");	/* frompcindex =     (calls frame) */
#endif not lint
	/*
	 *	check that we are profiling
	 */
	if (profiling) {
		goto out;
	}
	/*
	 *	insure that we cannot be recursively invoked.
	 *	this requires that splhigh() and splx() below
	 *	do NOT call mcount!
	 */
	s = splhigh();
	/*
	 *	check that frompcindex is a reasonable pc value.
	 *	for example:	signal catchers get called from the stack,
	 *			not from text space.  too bad.
	 */
	frompcindex = (unsigned short *)((long)frompcindex - (long)s_lowpc);
	if ((unsigned long)frompcindex > s_textsize) {
		goto done;
	}
	frompcindex =
	    &froms[((long)frompcindex) / (HASHFRACTION * sizeof(*froms))];
	toindex = *frompcindex;
	if (toindex == 0) {
		/*
		 *	first time traversing this arc
		 */
		toindex = ++tos[0].link;
		if (toindex >= tolimit) {
			goto overflow;
		}
		*frompcindex = toindex;
		top = &tos[toindex];
		top->selfpc = selfpc;
		top->count = 1;
		top->link = 0;
		goto done;
	}
	top = &tos[toindex];
	if (top->selfpc == selfpc) {
		/*
		 *	arc at front of chain; usual case.
		 */
		top->count++;
		goto done;
	}
	/*
	 *	have to go looking down chain for it.
	 *	top points to what we are looking at,
	 *	prevtop points to previous top.
	 *	we know it is not at the head of the chain.
	 */
	for (; /* goto done */; ) {
		if (top->link == 0) {
			/*
			 *	top is end of the chain and none of the chain
			 *	had top->selfpc == selfpc.
			 *	so we allocate a new tostruct
			 *	and link it to the head of the chain.
			 */
			toindex = ++tos[0].link;
			if (toindex >= tolimit) {
				goto overflow;
			}
			top = &tos[toindex];
			top->selfpc = selfpc;
			top->count = 1;
			top->link = *frompcindex;
			*frompcindex = toindex;
			goto done;
		}
		/*
		 *	otherwise, check the next arc on the chain.
		 */
		prevtop = top;
		top = &tos[top->link];
		if (top->selfpc == selfpc) {
			/*
			 *	there it is.
			 *	increment its count
			 *	move it to the head of the chain.
			 */
			top->count++;
			toindex = prevtop->link;
			prevtop->link = top->link;
			top->link = *frompcindex;
			*frompcindex = toindex;
			goto done;
		}

	}
done:
	splx(s);
	/* and fall through */
out:
	asm("	rsb");

overflow:
	profiling = 3;
	printf("mcount: tos overflow\n");
	goto out;
}
asm(".text");
asm("#the end of mcount()");
asm(".data");
#endif vax
#endif GPROF