freebsd-src/sys/kern/subr_param.c
Maxim Sobolev 7f03c419bc Default HZ value (1,000) on i386/amd64 is not very virtual machine friendly.
Due to the nature of the beast it causes lot of unproductive overhead. This
is especially bad when running SMP kernel on VMWare with several virtual
processors - idle FreeBSD guest with SMP kernel takes 150% host CPU time on my
dual-core MacBook Pro when I am enabling two virtual CPUs, making even host
not very usable. Detect when we are running in the sandbox and reduce HZ
to 10 (can be adjusted via VM_HZ in the kernel config) in such cases. This
brings host CPU usage of idle FreeBSD/SMP on two virtual processors down
to 10%.

Detect most popular VM platforms out there - VMWare, Parallels, VirtualBox
and VirtualPC.

MFC after:	2 weeks
2008-10-27 06:25:02 +00:00

247 lines
7 KiB
C

/*-
* Copyright (c) 1980, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* 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.
* 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.
*
* @(#)param.c 8.3 (Berkeley) 8/20/94
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_param.h"
#include "opt_maxusers.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <vm/vm_param.h>
/*
* System parameter formulae.
*/
#ifndef HZ
# if defined(__amd64__) || defined(__i386__) || defined(__ia64__) || defined(__sparc64__)
# define HZ 1000
# else
# define HZ 100
# endif
# ifndef HZ_VM
# define HZ_VM 10
# endif
#else
# ifndef HZ_VM
# define HZ_VM HZ
# endif
#endif
#define NPROC (20 + 16 * maxusers)
#ifndef NBUF
#define NBUF 0
#endif
#ifndef MAXFILES
#define MAXFILES (maxproc * 2)
#endif
int hz;
int tick;
int maxusers; /* base tunable */
int maxproc; /* maximum # of processes */
int maxprocperuid; /* max # of procs per user */
int maxfiles; /* sys. wide open files limit */
int maxfilesperproc; /* per-proc open files limit */
int ncallout; /* maximum # of timer events */
int nbuf;
int nswbuf;
int maxswzone; /* max swmeta KVA storage */
int maxbcache; /* max buffer cache KVA storage */
int maxpipekva; /* Limit on pipe KVA */
u_long maxtsiz; /* max text size */
u_long dfldsiz; /* initial data size limit */
u_long maxdsiz; /* max data size */
u_long dflssiz; /* initial stack size limit */
u_long maxssiz; /* max stack size */
u_long sgrowsiz; /* amount to grow stack */
SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN, &hz, 0, "ticks/second");
SYSCTL_INT(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN, &maxswzone, 0,
"max swmeta KVA storage");
SYSCTL_INT(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN, &maxbcache, 0,
"max buffer cache KVA storage");
SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RDTUN, &maxtsiz, 0,
"max text size");
SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RDTUN, &dfldsiz, 0,
"initial data size limit");
SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RDTUN, &maxdsiz, 0,
"max data size");
SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RDTUN, &dflssiz, 0,
"initial stack size limit");
SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RDTUN, &maxssiz, 0,
"max stack size");
SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RDTUN, &sgrowsiz, 0,
"amount to grow stack");
/*
* These have to be allocated somewhere; allocating
* them here forces loader errors if this file is omitted
* (if they've been externed everywhere else; hah!).
*/
struct buf *swbuf;
char *vm_pnames[] = {
"VMware Virtual Platform", /* VMWare VM */
"Virtual Machine", /* Microsoft VirtualPC */
"VirtualBox", /* Sun xVM VirtualBox */
"Parallels Virtual Platform", /* Parallels VM */
NULL
};
static int
detect_virtual(void)
{
char *sysenv;
int i;
sysenv = getenv("smbios.system.product");
if (sysenv != NULL) {
for (i = 0; vm_pnames[i] != NULL; i++) {
if (strcmp(sysenv, vm_pnames[i]) == 0)
return 1;
}
}
return 0;
}
/*
* Boot time overrides that are not scaled against main memory
*/
void
init_param1(void)
{
hz = -1;
TUNABLE_INT_FETCH("kern.hz", &hz);
if (hz == -1) {
if (detect_virtual()) {
hz = HZ_VM;
} else {
hz = HZ;
}
}
tick = 1000000 / hz;
#ifdef VM_SWZONE_SIZE_MAX
maxswzone = VM_SWZONE_SIZE_MAX;
#endif
TUNABLE_INT_FETCH("kern.maxswzone", &maxswzone);
#ifdef VM_BCACHE_SIZE_MAX
maxbcache = VM_BCACHE_SIZE_MAX;
#endif
TUNABLE_INT_FETCH("kern.maxbcache", &maxbcache);
maxtsiz = MAXTSIZ;
TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz);
dfldsiz = DFLDSIZ;
TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz);
maxdsiz = MAXDSIZ;
TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz);
dflssiz = DFLSSIZ;
TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz);
maxssiz = MAXSSIZ;
TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz);
sgrowsiz = SGROWSIZ;
TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz);
}
/*
* Boot time overrides that are scaled against main memory
*/
void
init_param2(long physpages)
{
/* Base parameters */
maxusers = MAXUSERS;
TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
if (maxusers == 0) {
maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE);
if (maxusers < 32)
maxusers = 32;
if (maxusers > 384)
maxusers = 384;
}
/*
* The following can be overridden after boot via sysctl. Note:
* unless overriden, these macros are ultimately based on maxusers.
*/
maxproc = NPROC;
TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
/*
* Limit maxproc so that kmap entries cannot be exhausted by
* processes.
*/
if (maxproc > (physpages / 12))
maxproc = physpages / 12;
maxfiles = MAXFILES;
TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
maxprocperuid = (maxproc * 9) / 10;
maxfilesperproc = (maxfiles * 9) / 10;
/*
* Cannot be changed after boot.
*/
nbuf = NBUF;
TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
ncallout = 16 + maxproc + maxfiles;
TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
}
/*
* Boot time overrides that are scaled against the kmem map
*/
void
init_param3(long kmempages)
{
/*
* The default for maxpipekva is max(5% of the kmem map, 512KB).
* See sys_pipe.c for more details.
*/
maxpipekva = (kmempages / 20) * PAGE_SIZE;
if (maxpipekva < 512 * 1024)
maxpipekva = 512 * 1024;
TUNABLE_INT_FETCH("kern.ipc.maxpipekva", &maxpipekva);
}