4.4BSD/usr/src/sys/kern/subr_prof.c
/*-
* Copyright (c) 1982, 1986, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)subr_prof.c 8.1 (Berkeley) 6/10/93
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <machine/cpu.h>
#ifdef GPROF
#include <sys/malloc.h>
#include <sys/gmon.h>
/*
* Froms is actually a bunch of unsigned shorts indexing tos
*/
struct gmonparam _gmonparam = { GMON_PROF_OFF };
extern char etext[];
kmstartup()
{
char *cp;
struct gmonparam *p = &_gmonparam;
/*
* 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(KERNBASE, HISTFRACTION * sizeof(HISTCOUNTER));
p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER));
p->textsize = p->highpc - p->lowpc;
printf("Profiling kernel, textsize=%d [%x..%x]\n",
p->textsize, p->lowpc, 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_NOWAIT);
if (cp == 0) {
printf("No memory for profiling.\n");
return;
}
bzero(cp, p->kcountsize + p->tossize + p->fromssize);
p->tos = (struct tostruct *)cp;
cp += p->tossize;
p->kcount = (u_short *)cp;
cp += p->kcountsize;
p->froms = (u_short *)cp;
}
/*
* Return kernel profiling information.
*/
sysctl_doprof(name, namelen, oldp, oldlenp, newp, newlen, p)
int *name;
u_int namelen;
void *oldp;
size_t *oldlenp;
void *newp;
size_t newlen;
{
struct gmonparam *gp = &_gmonparam;
int error;
/* all sysctl names at this level are terminal */
if (namelen != 1)
return (ENOTDIR); /* overloaded */
switch (name[0]) {
case GPROF_STATE:
error = sysctl_int(oldp, oldlenp, newp, newlen, &gp->state);
if (error)
return (error);
if (gp->state == GMON_PROF_OFF)
stopprofclock(&proc0);
else
startprofclock(&proc0);
return (0);
case GPROF_COUNT:
return (sysctl_struct(oldp, oldlenp, newp, newlen,
gp->kcount, gp->kcountsize));
case GPROF_FROMS:
return (sysctl_struct(oldp, oldlenp, newp, newlen,
gp->froms, gp->fromssize));
case GPROF_TOS:
return (sysctl_struct(oldp, oldlenp, newp, newlen,
gp->tos, gp->tossize));
case GPROF_GMONPARAM:
return (sysctl_rdstruct(oldp, oldlenp, newp, gp, sizeof *gp));
default:
return (EOPNOTSUPP);
}
/* NOTREACHED */
}
#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.
*/
struct profil_args {
caddr_t buf;
u_int bufsize;
u_int offset;
u_int scale;
};
/* ARGSUSED */
profil(p, uap, retval)
struct proc *p;
register struct profil_args *uap;
int *retval;
{
register struct uprof *upp;
int s;
if (uap->scale > (1 << 16))
return (EINVAL);
if (uap->scale == 0) {
stopprofclock(p);
return (0);
}
upp = &p->p_stats->p_prof;
s = splstatclock(); /* block profile interrupts while changing state */
upp->pr_base = uap->buf;
upp->pr_size = uap->bufsize;
upp->pr_off = uap->offset;
upp->pr_scale = uap->scale;
startprofclock(p);
splx(s);
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(p, pc, ticks)
register struct proc *p;
register u_long pc;
u_int ticks;
{
register struct uprof *prof;
register caddr_t addr;
register u_int i;
register int v;
if (ticks == 0)
return;
prof = &p->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) {
prof->pr_addr = pc;
prof->pr_ticks = ticks;
need_proftick(p);
}
}
/*
* Much like before, but we can afford to take faults here. If the
* update fails, we simply turn off profiling.
*/
void
addupc_task(p, pc, ticks)
register struct proc *p;
register u_long pc;
u_int ticks;
{
register struct uprof *prof;
register caddr_t addr;
register u_int i;
u_short v;
/* testing SPROFIL may be unnecessary, but is certainly safe */
if ((p->p_flag & SPROFIL) == 0 || ticks == 0)
return;
prof = &p->p_stats->p_prof;
if (pc < prof->pr_off ||
(i = PC_TO_INDEX(pc, prof)) >= prof->pr_size)
return;
addr = prof->pr_base + i;
if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) {
v += ticks;
if (copyout((caddr_t)&v, addr, sizeof(v)) == 0)
return;
}
stopprofclock(p);
}