/* _mcount; may be static, inline, etc */
_MCOUNT_DECL(uintfptr_t frompc, uintfptr_t selfpc)
{
#ifdef GUPROF
int delta;
#endif
fptrdiff_t frompci;
u_short *frompcindex;
struct tostruct *top, *prevtop;
struct gmonparam *p;
long toindex;
#if defined(_KERNEL) && !defined(_KERNEL_VIRTUAL)
MCOUNT_DECL(s)
#endif
p = &_gmonparam;
#ifndef GUPROF /* XXX */
/*
* check that we are profiling
* and that we aren't recursively invoked.
*/
if (p->state != GMON_PROF_ON)
return;
#endif
#if defined(_KERNEL) && !defined(_KERNEL_VIRTUAL)
MCOUNT_ENTER(s);
#else
p->state = GMON_PROF_BUSY;
#endif
frompci = frompc - p->lowpc;
#if defined(_KERNEL) && !defined(_KERNEL_VIRTUAL)
/*
* When we are called from an exception handler, frompci may be
* for a user address. Convert such frompci's to the index of
* user() to merge all user counts.
*
* XXX doesn't work properly with vkernel
*/
if (frompci >= p->textsize) {
if (frompci + p->lowpc
>= (uintfptr_t)(VM_MAX_USER_ADDRESS + UPAGES * PAGE_SIZE))
goto done;
frompci = (uintfptr_t)user - p->lowpc;
if (frompci >= p->textsize)
goto done;
}
#endif
#ifdef GUPROF
if (p->state == GMON_PROF_HIRES) {
/*
* Count the time since cputime() was previously called
* against `frompc'. Compensate for overheads.
*
* cputime() sets its prev_count variable to the count when
* it is called. This in effect starts a counter for
* the next period of execution (normally from now until
* the next call to mcount() or mexitcount()). We set
* cputime_bias to compensate for our own overhead.
*
* We use the usual sampling counters since they can be
* located efficiently. 4-byte counters are usually
* necessary. gprof will add up the scattered counts
* just like it does for statistical profiling. All
* counts are signed so that underflow in the subtractions
* doesn't matter much (negative counts are normally
* compensated for by larger counts elsewhere). Underflow
* shouldn't occur, but may be caused by slightly wrong
* calibrations or from not clearing cputime_bias.
*/
delta = cputime() - cputime_bias - p->mcount_pre_overhead;
cputime_bias = p->mcount_post_overhead;
KCOUNT(p, frompci) += delta;
*p->cputime_count += p->cputime_overhead;
*p->mcount_count += p->mcount_overhead;
}
#endif /* GUPROF */
#if defined(_KERNEL) && !defined(_KERNEL_VIRTUAL)
/*
* When we are called from an exception handler, frompc is faked
* to be for where the exception occurred. We've just solidified
* the count for there. Now convert frompci to the index of btrap()
* for trap handlers and bintr() for interrupt handlers to make
* exceptions appear in the call graph as calls from btrap() and
* bintr() instead of calls from all over.
*/
if ((uintfptr_t)selfpc >= (uintfptr_t)btrap
&& (uintfptr_t)selfpc < (uintfptr_t)eintr) {
if ((uintfptr_t)selfpc >= (uintfptr_t)bintr)
frompci = (uintfptr_t)bintr - p->lowpc;
else
frompci = (uintfptr_t)btrap - p->lowpc;
}
#endif
/*
* check that frompc is a reasonable pc value.
* for example: signal catchers get called from the stack,
* not from text space. too bad.
*/
if (frompci >= p->textsize)
goto done;
frompcindex = &p->froms[frompci / (p->hashfraction * sizeof(*p->froms))];
toindex = *frompcindex;
if (toindex == 0) {
/*
* first time traversing this arc
*/
toindex = ++p->tos[0].link;
if (toindex >= p->tolimit)
/* halt further profiling */
goto overflow;
*frompcindex = toindex;
top = &p->tos[toindex];
top->selfpc = selfpc;
top->count = 1;
top->link = 0;
goto done;
}
top = &p->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 = ++p->tos[0].link;
if (toindex >= p->tolimit)
goto overflow;
top = &p->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 = &p->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:
#if defined(_KERNEL) && !defined(_KERNEL_VIRTUAL)
MCOUNT_EXIT(s);
#else
p->state = GMON_PROF_ON;
#endif
return;
overflow:
p->state = GMON_PROF_ERROR;
#if defined(_KERNEL) && !defined(_KERNEL_VIRTUAL)
MCOUNT_EXIT(s);
#endif
return;
}
/* _mcount; may be static, inline, etc */
_MCOUNT_DECL(uintfptr_t frompc, uintfptr_t selfpc)
{
#ifdef GUPROF
u_int delta;
#endif
fptrdiff_t frompci;
u_short *frompcindex;
struct tostruct *top, *prevtop;
struct gmonparam *p;
long toindex;
#ifdef _KERNEL
MCOUNT_DECL(s)
#endif
p = &_gmonparam;
#ifndef GUPROF /* XXX */
/*
* check that we are profiling
* and that we aren't recursively invoked.
*/
if (p->state != GMON_PROF_ON)
return;
#endif
#ifdef _KERNEL
MCOUNT_ENTER(s);
#else
if (!atomic_cmpset_acq_int(&p->state, GMON_PROF_ON, GMON_PROF_BUSY))
return;
#endif
frompci = frompc - p->lowpc;
#ifdef _KERNEL
/*
* When we are called from an exception handler, frompci may be
* for a user address. Convert such frompci's to the index of
* user() to merge all user counts.
*/
if (frompci >= p->textsize) {
if (frompci + p->lowpc
>= (uintfptr_t)(VM_MAXUSER_ADDRESS + UPAGES * PAGE_SIZE))
goto done;
frompci = (uintfptr_t)user - p->lowpc;
if (frompci >= p->textsize)
goto done;
}
#endif
#ifdef GUPROF
if (p->state != GMON_PROF_HIRES)
goto skip_guprof_stuff;
/*
* Look at the clock and add the count of clock cycles since the
* clock was last looked at to a counter for frompc. This
* solidifies the count for the function containing frompc and
* effectively starts another clock for the current function.
* The count for the new clock will be solidified when another
* function call is made or the function returns.
*
* We use the usual sampling counters since they can be located
* efficiently. 4-byte counters are usually necessary.
*
* There are many complications for subtracting the profiling
* overheads from the counts for normal functions and adding
* them to the counts for mcount(), mexitcount() and cputime().
* We attempt to handle fractional cycles, but the overheads
* are usually underestimated because they are calibrated for
* a simpler than usual setup.
*/
delta = cputime() - p->mcount_overhead;
p->cputime_overhead_resid += p->cputime_overhead_frac;
p->mcount_overhead_resid += p->mcount_overhead_frac;
if ((int)delta < 0)
*p->mcount_count += delta + p->mcount_overhead
- p->cputime_overhead;
else if (delta != 0) {
if (p->cputime_overhead_resid >= CALIB_SCALE) {
p->cputime_overhead_resid -= CALIB_SCALE;
++*p->cputime_count;
--delta;
}
if (delta != 0) {
if (p->mcount_overhead_resid >= CALIB_SCALE) {
p->mcount_overhead_resid -= CALIB_SCALE;
++*p->mcount_count;
--delta;
}
KCOUNT(p, frompci) += delta;
}
*p->mcount_count += p->mcount_overhead_sub;
}
*p->cputime_count += p->cputime_overhead;
skip_guprof_stuff:
#endif /* GUPROF */
#ifdef _KERNEL
/*
* When we are called from an exception handler, frompc is faked
* to be for where the exception occurred. We've just solidified
* the count for there. Now convert frompci to the index of btrap()
* for trap handlers and bintr() for interrupt handlers to make
* exceptions appear in the call graph as calls from btrap() and
* bintr() instead of calls from all over.
*/
if ((uintfptr_t)selfpc >= (uintfptr_t)btrap
&& (uintfptr_t)selfpc < (uintfptr_t)eintr) {
if ((uintfptr_t)selfpc >= (uintfptr_t)bintr)
frompci = (uintfptr_t)bintr - p->lowpc;
else
frompci = (uintfptr_t)btrap - p->lowpc;
}
#endif
/*
* check that frompc is a reasonable pc value.
* for example: signal catchers get called from the stack,
* not from text space. too bad.
*/
if (frompci >= p->textsize)
goto done;
frompcindex = &p->froms[frompci / (p->hashfraction * sizeof(*p->froms))];
toindex = *frompcindex;
if (toindex == 0) {
/*
* first time traversing this arc
*/
toindex = ++p->tos[0].link;
if (toindex >= p->tolimit)
/* halt further profiling */
goto overflow;
*frompcindex = toindex;
top = &p->tos[toindex];
top->selfpc = selfpc;
top->count = 1;
top->link = 0;
goto done;
}
top = &p->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 = ++p->tos[0].link;
if (toindex >= p->tolimit)
goto overflow;
top = &p->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 = &p->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:
#ifdef _KERNEL
MCOUNT_EXIT(s);
#else
atomic_store_rel_int(&p->state, GMON_PROF_ON);
#endif
return;
overflow:
atomic_store_rel_int(&p->state, GMON_PROF_ERROR);
#ifdef _KERNEL
MCOUNT_EXIT(s);
#endif
return;
}