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Add a new routine kvm_getcptime(3) for fetching the equivalent of

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'kern.cp_time'.  For a live kernel it uses the sysctl.  For a crashdump,
it first checks to see if the kernel has a 'cp_time' global symbol.  If
it does, it uses that.  If that doesn't work, when it uses the recently
added kvm_getmaxcpu(3) and kvm_getpcpu(3) routines to walk all the CPUs
and sum up their counters.

MFC after:	1 week
This commit is contained in:
jhb 2008-08-19 21:30:36 +00:00
parent 10e058a3a2
commit 67b02c52de
4 changed files with 214 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
lib/libkvm/Makefile
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@ -9,15 +9,16 @@ CFLAGS+=-DLIBC_SCCS -I${.CURDIR}
CFLAGS+=-DSUN4V
.endif
SRCS= kvm.c kvm_${MACHINE_ARCH}.c kvm_file.c kvm_getloadavg.c \
SRCS= kvm.c kvm_${MACHINE_ARCH}.c kvm_cptime.c kvm_file.c kvm_getloadavg.c \
kvm_getswapinfo.c kvm_pcpu.c kvm_proc.c
.if ${MACHINE_ARCH} == "amd64" || ${MACHINE_ARCH} == "i386"
SRCS+= kvm_minidump_${MACHINE_ARCH}.c
.endif
INCS= kvm.h
MAN= kvm.3 kvm_geterr.3 kvm_getfiles.3 kvm_getloadavg.3 kvm_getpcpu.3 \
kvm_getprocs.3 kvm_getswapinfo.3 kvm_nlist.3 kvm_open.3
MAN= kvm.3 kvm_getcptime.3 kvm_geterr.3 kvm_getfiles.3 kvm_getloadavg.3 \
kvm_getpcpu.3 kvm_getprocs.3 kvm_getswapinfo.3 kvm_nlist.3 kvm_open.3 \
kvm_read.3
MLINKS+=kvm_getpcpu.3 kvm_getmaxcpu.3
MLINKS+=kvm_getprocs.3 kvm_getargv.3 kvm_getprocs.3 kvm_getenvv.3

1
lib/libkvm/kvm.h
View File

@ -70,6 +70,7 @@ struct kvm_swap {
__BEGIN_DECLS
int kvm_close(kvm_t *);
char **kvm_getargv(kvm_t *, const struct kinfo_proc *, int);
int kvm_getcptime(kvm_t *, long *);
char **kvm_getenvv(kvm_t *, const struct kinfo_proc *, int);
char *kvm_geterr(kvm_t *);
char *kvm_getfiles(kvm_t *, int, int, int *);

132
lib/libkvm/kvm_cptime.c Normal file
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@ -0,0 +1,132 @@
/*-
* Copyright (c) 2008 Yahoo!, Inc.
* All rights reserved.
* Written by: John Baldwin <jhb@FreeBSD.org>
*
* 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 author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/pcpu.h>
#include <sys/resource.h>
#include <sys/sysctl.h>
#include <errno.h>
#include <kvm.h>
#include <limits.h>
#include <stdlib.h>
#include "kvm_private.h"
static struct nlist kvm_cp_time_nl[] = {
{ "_cp_time" }, /* (deprecated) */
{ NULL },
};
#define NL_CP_TIME 0
static int kvm_cp_time_cached;
static int
_kvm_cp_time_init(kvm_t *kd)
{
if (kvm_nlist(kd, kvm_cp_time_nl) < 0)
return (-1);
kvm_cp_time_cached = 1;
}
static int
getsysctl(kvm_t *kd, const char *name, void *buf, size_t len)
{
size_t nlen;
nlen = len;
if (sysctlbyname(name, buf, &nlen, NULL, 0) < 0) {
_kvm_err(kd, kd->program, "cannot read sysctl %s:%s", name,
strerror(errno));
return (-1);
}
if (nlen != len) {
_kvm_err(kd, kd->program, "sysctl %s has unexpected size",
name);
return (-1);
}
return (0);
}
int
kvm_getcptime(kvm_t *kd, long *cp_time)
{
struct pcpu *pc;
int i, j, maxcpu;
if (kd == NULL) {
kvm_cp_time_cached = 0;
return (0);
}
if (ISALIVE(kd))
return (getsysctl(kd, "kern.cp_time", cp_time, sizeof(long) *
CPUSTATES));
if (kvm_cp_time_cached == 0) {
if (_kvm_cp_time_init(kd) < 0)
return (-1);
}
/* If this kernel has a "cp_time[]" symbol, then just read that. */
if (kvm_cp_time_nl[NL_CP_TIME].n_value != 0) {
if (kvm_read(kd, kvm_cp_time_nl[NL_CP_TIME].n_value, cp_time,
sizeof(long) * CPUSTATES) != sizeof(long) * CPUSTATES) {
_kvm_err(kd, kd->program, "cannot read cp_time array");
return (-1);
}
return (0);
}
/*
* If we don't have that symbol, then we have to simulate
* "cp_time[]" by adding up the individual times for each CPU.
*/
maxcpu = kvm_getmaxcpu(kd);
if (maxcpu < 0)
return (-1);
for (i = 0; i < CPUSTATES; i++)
cp_time[i] = 0;
for (i = 0; i < maxcpu; i++) {
pc = kvm_getpcpu(kd, i);
if (pc == NULL)
continue;
if (pc == (void *)-1)
return (-1);
for (j = 0; j < CPUSTATES; j++)
cp_time[j] += pc->pc_cp_time[j];
free(pc);
}
return (0);
}

77
lib/libkvm/kvm_getcptime.3 Normal file
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@ -0,0 +1,77 @@
.\" Copyright (c) 2008 Yahoo!, Inc.
.\" All rights reserved.
.\" Written by: John Baldwin <jhb@FreeBSD.org>
.\"
.\" 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 author nor the names of any co-contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
.\"
.\" $FreeBSD$
.\"
.Dd August 19, 2008
.Dt KVM_GETCPTIME 3
.Os
.Sh NAME
.Nm kvm_getcptime
.Nd fetch global CPU time statistics
.Sh LIBRARY
.Lb libkvm
.Sh SYNOPSIS
.In sys/param.h
.In sys/resource.h
.In sys/sysctl.h
.In kvm.h
.Ft int
.Fn kvm_getcptime "kvm_t *kd" "long *cp_time"
.Sh DESCRIPTION
The
.Fn kvm_getcptime
function stores the global CPU time statistics from the kernel
.Fa kd
in the array of counters pointed to by
.Fa cp_time .
Note that
.Fa cp_time
should point to an array of
.Dv CPUSTATES
long integers.
The format of the counters is identical to that output by the
.Va kern.cp_time
sysctl.
.Sh CACHING
This function caches the nlist values for various kernel variables which it
reuses in successive calls.
You may call the function with
.Fa kd
set to
.Dv NULL
to clear this cache.
.Sh RETURN VALUES
The
.Nm kvm_getcptime
function returns 0 on success and -1 on failure.
If an error occurs,
then an error message may be retrieved via
.Xr kvm_geterr 3 .
.Sh SEE ALSO
.Xr kvm 3