Imported from util-linux-2.13-pre1 tarball.

1 files changed, 223 insertions, 0 deletions

diff --git a/schedutils/chrt.c b/schedutils/chrt.c
new file mode 100644
index 000000000..b61ed52ad
--- /dev/null
+++ b/schedutils/chrt.c
@@ -0,0 +1,223 @@
+/*
+ * chrt.c - chrt
+ * Command-line utility for manipulating a task's real-time attributes 
+ *
+ * Robert Love <rml@tech9.net>
+ * 27-Apr-2002: initial version
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, v2, as
+ * published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Copyright (C) 2004 Robert Love
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sched.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <errno.h>
+
+static void show_usage(const char *cmd)
+{
+	fprintf(stderr, "chrt version " VERSION "\n");
+	fprintf(stderr, "usage: %s [options] [prio] [pid | cmd [args...]]\n",
+			cmd);
+	fprintf(stderr, "manipulate real-time attributes of a process\n");
+	fprintf(stderr, "  -f, --fifo                         "
+			"set policy to SCHED_FF\n");
+	fprintf(stderr, "  -p, --pid                          "
+			"operate on existing given pid\n");
+	fprintf(stderr, "  -m, --max                          "
+			"show min and max valid priorities\n");
+	fprintf(stderr, "  -o, --other                        "
+			"set policy to SCHED_OTHER\n");
+	fprintf(stderr, "  -r, --rr                           "
+			"set policy to SCHED_RR (default)\n");
+	fprintf(stderr, "  -h, --help                         "
+			"display this help\n");
+	fprintf(stderr, "  -v, --verbose                      "
+			"display status information\n");
+	fprintf(stderr, "  -V, --version                      "
+			"output version information\n\n");
+	fprintf(stderr, "You must give a priority if changing policy.\n\n");
+	fprintf(stderr, "Report bugs and send patches to <rml@tech9.net>\n");
+}
+
+static void show_rt_info(const char *what, pid_t pid)
+{
+	struct sched_param sp;
+	int policy;
+
+	/* don't display "pid 0" as that is confusing */
+	if (!pid)
+		pid = getpid();
+
+	policy = sched_getscheduler(pid);
+	if (policy == -1) {
+		perror("sched_getscheduler");
+		fprintf(stderr, "failed to get pid %d's policy\n", pid);
+		exit(1);
+	}
+
+	printf("pid %d's %s scheduling policy: ", pid, what);
+	switch (policy) {
+	case SCHED_OTHER:
+		printf("SCHED_OTHER\n");
+		break;
+	case SCHED_FIFO:
+		printf("SCHED_FIFO\n");
+		break;
+	case SCHED_RR:
+		printf("SCHED_RR\n");
+		break;
+	default:
+		printf("unknown\n");
+	}
+
+	if (sched_getparam(pid, &sp)) {
+		perror("sched_getparam");
+		fprintf(stderr, "failed to get pid %d's attributes\n", pid);
+		exit(1);
+	}
+
+	printf("pid %d's %s scheduling priority: %d\n",
+		pid, what, sp.sched_priority);
+}
+
+static void show_min_max(void)
+{
+	int max, min;
+
+	max = sched_get_priority_max(SCHED_FIFO);
+	min = sched_get_priority_min(SCHED_FIFO);
+	if (max >= 0 && min >= 0)
+		printf("SCHED_FIFO min/max priority\t: %d/%d\n", min, max);
+	else
+		printf("SCHED_FIFO not supported?\n");
+
+	max = sched_get_priority_max(SCHED_RR);
+	min = sched_get_priority_min(SCHED_RR);
+	if (max >= 0 && min >= 0)
+		printf("SCHED_RR min/max priority\t: %d/%d\n", min, max);
+	else
+		printf("SCHED_RR not supported?\n");
+
+	max = sched_get_priority_max(SCHED_OTHER);
+	min = sched_get_priority_min(SCHED_OTHER);
+	if (max >= 0 && min >= 0)
+		printf("SCHED_OTHER min/max priority\t: %d/%d\n", min, max);
+	else
+		printf("SCHED_OTHER not supported?\n");
+}
+
+int main(int argc, char *argv[])
+{
+	int i, policy = SCHED_RR, priority = 0, verbose = 0;
+	struct sched_param sp;
+	pid_t pid = 0;
+
+	struct option longopts[] = {
+		{ "fifo",	0, NULL, 'f' },
+		{ "pid",	0, NULL, 'p' },
+		{ "help",	0, NULL, 'h' },
+		{ "max",        0, NULL, 'm' },
+		{ "other",	0, NULL, 'o' },
+		{ "rr",		0, NULL, 'r' },
+		{ "verbose",	0, NULL, 'v' },
+		{ "version",	0, NULL, 'V' },
+		{ NULL,		0, NULL, 0 }
+	};
+
+	while((i = getopt_long(argc, argv, "+fphmorvV", longopts, NULL)) != -1)
+	{
+		int ret = 1;
+
+		switch (i) {
+		case 'f':
+			policy = SCHED_FIFO;
+			break;
+		case 'm':
+			show_min_max();
+			return 0;
+		case 'o':
+			policy = SCHED_OTHER;
+			break;
+		case 'p':
+			errno = 0;
+			pid = strtol(argv[argc - 1], NULL, 10);
+			if (errno) {
+				perror("strtol");
+				fprintf(stderr, "failed to parse pid!\n");
+				return 1;
+			}
+			break;
+		case 'r':
+			policy = SCHED_RR;
+			break;
+		case 'v':
+			verbose = 1;
+			break;
+		case 'V':
+			printf("chrt version " VERSION "\n");
+			return 0;
+		case 'h':
+			ret = 0;
+		default:
+			show_usage(argv[0]);
+			return ret;
+		}
+		
+	}
+
+	if ((pid && argc - optind < 1) || (!pid && argc - optind < 2)) {
+		show_usage(argv[0]);
+		return 1;
+	}
+
+	if (pid && (verbose || argc - optind == 1)) {
+		show_rt_info("current", pid);
+		if (argc - optind == 1)
+			return 0;
+	}
+
+	errno = 0;
+	priority = strtol(argv[optind], NULL, 10);
+	if (errno) {
+		perror("strtol");
+		fprintf(stderr, "failed to parse priority!\n");
+		return 1;
+	}
+
+	sp.sched_priority = priority;
+	if (sched_setscheduler(pid, policy, &sp) == -1) {
+		perror("sched_setscheduler");
+		fprintf(stderr, "failed to set pid %d's policy\n", pid);
+		return 1;
+	}
+
+	if (verbose)
+		show_rt_info("new", pid);
+
+	if (!pid) {
+		argv += optind + 1;
+		execvp(argv[0], argv);
+		perror("execvp");
+		fprintf(stderr, "failed to execute %s\n", argv[0]);
+		return 1;
+	}
+
+	return 0;
+}