util-linux/sys-utils/choom.c

160 lines
4.1 KiB
C

/*
* choom - Change OOM score setting
*
* Copyright (C) 2018 Karel Zak <kzak@redhat.com>
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <getopt.h>
#include <errno.h>
#include "nls.h"
#include "c.h"
#include "path.h"
#include "strutils.h"
#include "closestream.h"
static void __attribute__((__noreturn__)) usage(void)
{
FILE *out = stdout;
fputs(USAGE_HEADER, out);
fprintf(out,
_(" %1$s [options] -p pid\n"
" %1$s [options] -n number -p pid\n"
" %1$s [options] -n number [--] command [args...]]\n"),
program_invocation_short_name);
fputs(USAGE_SEPARATOR, out);
fputs(_("Display and adjust OOM-killer score.\n"), out);
fputs(USAGE_OPTIONS, out);
fputs(_(" -n, --adjust <num> specify the adjust score value\n"), out);
fputs(_(" -p, --pid <num> process ID\n"), out);
fputs(USAGE_SEPARATOR, out);
printf(USAGE_HELP_OPTIONS(24));
printf(USAGE_MAN_TAIL("choom(1)"));
exit(EXIT_SUCCESS);
}
static int get_score(struct path_cxt *pc)
{
int ret;
if (ul_path_read_s32(pc, &ret, "oom_score") != 0)
err(EXIT_FAILURE, _("failed to read OOM score value"));
return ret;
}
static int get_score_adj(struct path_cxt *pc)
{
int ret;
if (ul_path_read_s32(pc, &ret, "oom_score_adj") != 0)
err(EXIT_FAILURE, _("failed to read OOM score adjust value"));
return ret;
}
static int set_score_adj(struct path_cxt *pc, int adj)
{
return ul_path_write_s64(pc, adj, "oom_score_adj");
}
int main(int argc, char **argv)
{
pid_t pid = 0;
int c, adj = 0, has_adj = 0;
struct path_cxt *pc = NULL;
static const struct option longopts[] = {
{ "adjust", required_argument, NULL, 'n' },
{ "pid", required_argument, NULL, 'p' },
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
{ NULL, 0, NULL, 0 }
};
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
close_stdout_atexit();
while ((c = getopt_long(argc, argv, "hn:p:V", longopts, NULL)) != -1) {
switch (c) {
case 'p':
pid = strtos32_or_err(optarg, _("invalid PID argument"));
break;
case 'n':
adj = strtos32_or_err(optarg, _("invalid adjust argument"));
has_adj = 1;
break;
case 'V':
print_version(EXIT_SUCCESS);
case 'h':
usage();
default:
errtryhelp(EXIT_FAILURE);
}
}
if (optind < argc && pid) {
warnx(_("invalid argument: %s"), argv[optind]);
errtryhelp(EXIT_FAILURE);
}
if (!pid && argc - optind < 1) {
warnx(_("no PID or COMMAND specified"));
errtryhelp(EXIT_FAILURE);
}
if (optind < argc && !has_adj) {
warnx(_("no OOM score adjust value specified"));
errtryhelp(EXIT_FAILURE);
}
pc = ul_new_path("/proc/%d", (int) (pid ? pid : getpid()));
/* Show */
if (!has_adj) {
printf(_("pid %d's current OOM score: %d\n"), pid, get_score(pc));
printf(_("pid %d's current OOM score adjust value: %d\n"), pid, get_score_adj(pc));
/* Change */
} else if (pid) {
int old = get_score_adj(pc);
if (set_score_adj(pc, adj))
err(EXIT_FAILURE, _("failed to set score adjust value"));
printf(_("pid %d's OOM score adjust value changed from %d to %d\n"), pid, old, adj);
/* Start new process */
} else {
if (set_score_adj(pc, adj))
err(EXIT_FAILURE, _("failed to set score adjust value"));
ul_unref_path(pc);
argv += optind;
execvp(argv[0], argv);
errexec(argv[0]);
}
ul_unref_path(pc);
return EXIT_SUCCESS;
}