NetBSD/sys/kern/subr_prof.c

330 lines
9.3 KiB
C

/* $NetBSD: subr_prof.c,v 1.31 2004/04/08 06:20:30 atatat Exp $ */
/*-
* 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. 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 8.4 (Berkeley) 2/14/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: subr_prof.c,v 1.31 2004/04/08 06:20:30 atatat Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/mount.h>
#include <sys/sa.h>
#include <sys/syscallargs.h>
#include <sys/sysctl.h>
#include <machine/cpu.h>
#ifdef GPROF
#include <sys/malloc.h>
#include <sys/gmon.h>
MALLOC_DEFINE(M_GPROF, "gprof", "kernel profiling buffer");
/*
* Froms is actually a bunch of unsigned shorts indexing tos
*/
struct gmonparam _gmonparam = { GMON_PROF_OFF };
/* Actual start of the kernel text segment. */
extern char kernel_text[];
extern char etext[];
void
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(((u_long)kernel_text),
HISTFRACTION * sizeof(HISTCOUNTER));
p->highpc = ROUNDUP((u_long)etext,
HISTFRACTION * sizeof(HISTCOUNTER));
p->textsize = p->highpc - p->lowpc;
printf("Profiling kernel, textsize=%ld [%lx..%lx]\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;
}
memset(cp, 0, 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 helper routine for kern.profiling subtree. enables/disables
* kernel profiling and gives out copies of the profiling data.
*/
static int
sysctl_kern_profiling(SYSCTLFN_ARGS)
{
struct gmonparam *gp = &_gmonparam;
int error;
struct sysctlnode node;
node = *rnode;
switch (node.sysctl_num) {
case GPROF_STATE:
node.sysctl_data = &gp->state;
break;
case GPROF_COUNT:
node.sysctl_data = gp->kcount;
node.sysctl_size = gp->kcountsize;
break;
case GPROF_FROMS:
node.sysctl_data = gp->froms;
node.sysctl_size = gp->fromssize;
break;
case GPROF_TOS:
node.sysctl_data = gp->tos;
node.sysctl_size = gp->tossize;
break;
case GPROF_GMONPARAM:
node.sysctl_data = gp;
node.sysctl_size = sizeof(*gp);
break;
default:
return (EOPNOTSUPP);
}
error = sysctl_lookup(SYSCTLFN_CALL(&node));
if (error || newp == NULL)
return (error);
if (node.sysctl_num == GPROF_STATE) {
if (gp->state == GMON_PROF_OFF)
stopprofclock(&proc0);
else
startprofclock(&proc0);
}
return (0);
}
SYSCTL_SETUP(sysctl_kern_gprof_setup, "sysctl kern.profiling subtree setup")
{
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "kern", NULL,
NULL, 0, NULL, 0,
CTL_KERN, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "profiling",
SYSCTL_DESCR("Profiling information (available)"),
NULL, 0, NULL, 0,
CTL_KERN, KERN_PROF, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_INT, "state",
SYSCTL_DESCR("Profiling state"),
sysctl_kern_profiling, 0, NULL, 0,
CTL_KERN, KERN_PROF, GPROF_STATE, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_STRUCT, "count",
SYSCTL_DESCR("Array of statistical program counters"),
sysctl_kern_profiling, 0, NULL, 0,
CTL_KERN, KERN_PROF, GPROF_COUNT, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_STRUCT, "froms",
SYSCTL_DESCR("Array indexed by program counter of "
"call-from points"),
sysctl_kern_profiling, 0, NULL, 0,
CTL_KERN, KERN_PROF, GPROF_FROMS, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_STRUCT, "tos",
SYSCTL_DESCR("Array of structures describing "
"destination of calls and their counts"),
sysctl_kern_profiling, 0, NULL, 0,
CTL_KERN, KERN_PROF, GPROF_TOS, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_STRUCT, "gmonparam",
SYSCTL_DESCR("Structure giving the sizes of the above "
"arrays"),
sysctl_kern_profiling, 0, NULL, 0,
CTL_KERN, KERN_PROF, GPROF_GMONPARAM, CTL_EOL);
}
#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.
*/
/* ARGSUSED */
int
sys_profil(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct sys_profil_args /* {
syscallarg(caddr_t) samples;
syscallarg(u_int) size;
syscallarg(u_int) offset;
syscallarg(u_int) scale;
} */ *uap = v;
struct proc *p = l->l_proc;
struct uprof *upp;
int s;
if (SCARG(uap, scale) > (1 << 16))
return (EINVAL);
if (SCARG(uap, scale) == 0) {
stopprofclock(p);
return (0);
}
upp = &p->p_stats->p_prof;
/* Block profile interrupts while changing state. */
s = splstatclock();
upp->pr_off = SCARG(uap, offset);
upp->pr_scale = SCARG(uap, scale);
upp->pr_base = SCARG(uap, samples);
upp->pr_size = SCARG(uap, size);
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)
struct proc *p;
u_long pc;
{
struct uprof *prof;
caddr_t addr;
u_int i;
int v;
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 + 1) == -1) {
prof->pr_addr = pc;
prof->pr_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)
struct proc *p;
u_long pc;
u_int ticks;
{
struct uprof *prof;
caddr_t addr;
u_int i;
u_short v;
/* Testing P_PROFIL may be unnecessary, but is certainly safe. */
if ((p->p_flag & P_PROFIL) == 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);
}