From: Heiko Carstens <heiko.carstens@xxxxxxxxxx> The chcpu lets a user configure CPUs. In this first version all that is possible is to enable or disable CPUs (set them online of offline). This is quite useful if you work a lot with virtual servers, since enabling and disabling cpus via sysfs becomes tiring. Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx> --- sys-utils/.gitignore | 1 + sys-utils/Makefile.am | 3 + sys-utils/chcpu.1 | 56 ++++++++++++ sys-utils/chcpu.c | 222 +++++++++++++++++++++++++++++++++++++++++++++++++ sys-utils/lscpu.1 | 2 + 5 files changed, 284 insertions(+), 0 deletions(-) create mode 100644 sys-utils/chcpu.1 create mode 100644 sys-utils/chcpu.c diff --git a/sys-utils/.gitignore b/sys-utils/.gitignore index 3ae7e4a..febeb38 100644 --- a/sys-utils/.gitignore +++ b/sys-utils/.gitignore @@ -41,3 +41,4 @@ switch_root tunelp unshare x86_64.8 +chcpu diff --git a/sys-utils/Makefile.am b/sys-utils/Makefile.am index feb5888..da05dac 100644 --- a/sys-utils/Makefile.am +++ b/sys-utils/Makefile.am @@ -21,6 +21,9 @@ if HAVE_CPU_SET_T usrbin_exec_PROGRAMS += lscpu lscpu_SOURCES = lscpu.c $(top_srcdir)/lib/cpuset.c $(top_srcdir)/lib/strutils.c dist_man_MANS += lscpu.1 +sbin_PROGRAMS += chcpu +chcpu_SOURCES = chcpu.c $(top_srcdir)/lib/cpuset.c +dist_man_MANS += chcpu.1 endif endif diff --git a/sys-utils/chcpu.1 b/sys-utils/chcpu.1 new file mode 100644 index 0000000..0b9e98a --- /dev/null +++ b/sys-utils/chcpu.1 @@ -0,0 +1,56 @@ +.TH CHCPU 1 "August 2011" Linux "User Manuals" +.SH NAME +chcpu \- CPU configuration utility +.SH SYNOPSIS +.B chcpu +.RB [ \-hvV ] +.RB [ \-d +.IR cpulist ] +.RB [ \-e +.IR cpulist ] +.SH DESCRIPTION +.B chcpu +is used to configure CPUs. It can enable and disable CPUs by writing to the +per CPU sysfs file attributes. +Some options have a \fIcpu-list\fP argument. A \fIcpu-list\fP may specify +multiple CPUs, separated by comma, and ranges. For example, +.BR 0,5,7,9-11 . +.SH OPTIONS +The --disable and --enable options are mutually exclusive. +.TP +.BR \-d , " \-\-disable " \fIcpu-list\fP +disable all CPUs specified with \fIcpu-list\fP. If +.BR chcpu +fails to disable a CPU specified in the \fIcpu-list\fP it will skip that +CPU and continue with the next one until all specified CPUs have been +processed. +.TP +.BR \-e , " \-\-enable " \fIcpu-list\fP +enable all CPUs specified with \fIcpu-list\fP. If +.BR chcpu +fails to enable a CPU specified in the \fIcpu-list\fP it will skip that +CPU and continue with the next one until all specified CPUs have been +processed. +.TP +.BR \-h , " \-\-help" +Print a help text and exit. +.TP +.BR \-v , " \-\-verbose" +Verbose execution. When specified +.B chcpu +will output the result of the configuration changes for each CPU. +.TP +.BR \-V , " \-\-version" +Output version information and exit. +.SH AUTHOR +.nf +Heiko Carstens <heiko.carstens@xxxxxxxxxx> +.fi +.SH COPYRIGHT +Copyright IBM Corp. 2011 +.br +.SH "SEE ALSO" +.BR lscpu (1) +.SH AVAILABILITY +The chcpu command is part of the util-linux package and is available from +ftp://ftp.kernel.org/pub/linux/utils/util-linux/. diff --git a/sys-utils/chcpu.c b/sys-utils/chcpu.c new file mode 100644 index 0000000..6e4392d --- /dev/null +++ b/sys-utils/chcpu.c @@ -0,0 +1,222 @@ +/* + * chcpu - CPU configuration tool + * + * Copyright IBM Corp. 2011 + * Author(s): Heiko Carstens <heiko.carstens@xxxxxxxxxx>, + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <ctype.h> +#include <dirent.h> +#include <errno.h> +#include <fcntl.h> +#include <getopt.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/utsname.h> +#include <unistd.h> +#include <stdarg.h> +#include <sys/types.h> +#include <sys/stat.h> + +#include "cpuset.h" +#include "nls.h" +#include "xalloc.h" +#include "c.h" +#include "strutils.h" +#include "bitops.h" + +#define _PATH_SYS_CPU "/sys/devices/system/cpu" + +static char pathbuf[PATH_MAX]; +static int verbose; + +enum { + CMD_CPU_ENABLE = 0, + CMD_CPU_DISABLE, +}; + +static int path_open(mode_t mode, const char *path, ...) +{ + va_list ap; + int fd; + + va_start(ap, path); + vsnprintf(pathbuf, sizeof(pathbuf), path, ap); + va_end(ap); + fd = open(pathbuf, mode); + if (fd == -1) + err(EXIT_FAILURE, "error: cannot open %s", pathbuf); + return fd; +} + +static int path_exist(const char *path, ...) +{ + va_list ap; + + va_start(ap, path); + vsnprintf(pathbuf, sizeof(pathbuf), path, ap); + va_end(ap); + return access(pathbuf, F_OK) == 0; +} + +static void print_v(const char *str, ...) +{ + va_list ap; + + if (!verbose) + return; + va_start(ap, str); + vprintf(str, ap); + va_end(ap); +} + +static int cpu_enable(cpu_set_t *cpu_set, size_t setsize, int enable) +{ + unsigned int cpu; + int fd, rc; + char c; + + for (cpu = 0; cpu < setsize; cpu++) { + if (!CPU_ISSET(cpu, cpu_set)) + continue; + if (!path_exist(_PATH_SYS_CPU "/cpu%d", cpu)) { + print_v(_("CPU %d does not exist\n"), cpu); + continue; + } + if (!path_exist(_PATH_SYS_CPU "/cpu%d/online", cpu)) { + print_v(_("CPU %d is not hot pluggable\n"), cpu); + continue; + } + fd = path_open(O_RDWR, _PATH_SYS_CPU "/cpu%d/online", cpu); + if (read(fd, &c, 1) == -1) + err(EXIT_FAILURE, "error: cannot read from %s", pathbuf); + if ((c == '1') && (enable == 1)) { + print_v(_("CPU %d already enabled\n"), cpu); + continue; + } + if ((c == '0') && (enable == 0)) { + print_v(_("CPU %d already disabled\n"), cpu); + continue; + } + if (enable) { + rc = write(fd, "1", 1); + if (rc == -1) + print_v(_("CPU %d enable failed (%s)\n"), cpu, + strerror(errno)); + else + print_v(_("CPU %d enabled\n"), cpu); + } else { + rc = write(fd, "0", 1); + if (rc == -1) + print_v(_("CPU %d disable failed (%s)\n"), cpu, + strerror(errno)); + else + print_v(_("CPU %d disabled\n"), cpu); + } + close(fd); + } + return EXIT_SUCCESS; +} + +static void __attribute__((__noreturn__)) usage(FILE *out) +{ + fprintf(out, _( + "\nUsage:\n" + " %s [options] [cpu-list]\n"), program_invocation_short_name); + + puts(_( "\nOptions:\n" + " -h, --help print this help\n" + " -e, --enable enable cpus\n" + " -d, --disable disable cpus\n" + " -v, --verbose explain what is being done\n" + " -V, --version output version information and exit\n")); + + exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS); +} + +int main(int argc, char *argv[]) +{ + cpu_set_t *cpu_set; + unsigned int ncpus; + size_t setsize; + int cmd = -1; + int c; + + static const struct option longopts[] = { + { "disable", required_argument, 0, 'd' }, + { "enable", required_argument, 0, 'e' }, + { "help", no_argument, 0, 'h' }, + { "verbose", no_argument, 0, 'v' }, + { "version", no_argument, 0, 'V' }, + { NULL, 0, 0, 0 } + }; + + setlocale(LC_ALL, ""); + bindtextdomain(PACKAGE, LOCALEDIR); + textdomain(PACKAGE); + + ncpus = get_max_number_of_cpus(); + if (ncpus <= 0) + errx(EXIT_FAILURE, _("cannot determine NR_CPUS; aborting")); + setsize = CPU_ALLOC_SIZE(ncpus); + cpu_set = CPU_ALLOC(ncpus); + if (!cpu_set) + err(EXIT_FAILURE, _("cpuset_alloc failed")); + + while ((c = getopt_long(argc, argv, "he:d:vV", longopts, NULL)) != -1) { + if (cmd != -1 && strchr("de", c)) + errx(EXIT_FAILURE, + _("disable and enable are mutually exclusive")); + switch (c) { + case 'h': + usage(stdout); + case 'e': + cmd = CMD_CPU_ENABLE; + if (cpulist_parse(argv[optind - 1], cpu_set, setsize, 1)) + errx(EXIT_FAILURE, _("failed to parse CPU list: %s"), + argv[optind -1 ]); + break; + case 'd': + cmd = CMD_CPU_DISABLE; + if (cpulist_parse(argv[optind - 1], cpu_set, setsize, 1)) + errx(EXIT_FAILURE, _("failed to parse CPU list: %s"), + argv[optind -1 ]); + break; + case 'v': + verbose = 1; + break; + case 'V': + printf(_("%s from %s\n"), program_invocation_short_name, + PACKAGE_STRING); + return EXIT_SUCCESS; + default: + usage(stderr); + } + } + + if ((argc == 1) || (argc != optind)) + usage(stderr); + + switch (cmd) { + case CMD_CPU_ENABLE: + return cpu_enable(cpu_set, ncpus, 1); + case CMD_CPU_DISABLE: + return cpu_enable(cpu_set, ncpus, 0); + } + return EXIT_SUCCESS; +} diff --git a/sys-utils/lscpu.1 b/sys-utils/lscpu.1 index 4795e91..39246c9 100644 --- a/sys-utils/lscpu.1 +++ b/sys-utils/lscpu.1 @@ -56,6 +56,8 @@ Sometimes in Xen Dom0 the kernel reports wrong data. Cai Qian <qcai@xxxxxxxxxx> Karel Zak <kzak@xxxxxxxxxx> .fi +.SH "SEE ALSO" +.BR chcpu (1) .SH AVAILABILITY The lscpu command is part of the util-linux package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux/. -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
