Imported from util-linux-2.10m tarball.

1 files changed, 143 insertions, 0 deletions

diff --git a/disk-utils/elvtune.c b/disk-utils/elvtune.c
new file mode 100644
index 000000000..00640fede
--- /dev/null
+++ b/disk-utils/elvtune.c
@@ -0,0 +1,143 @@
+/*
+ *  elvtune.c - I/O elevator tuner
+ *
+ *  Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
+ *
+ *  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 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.
+ *  This file may be redistributed under the terms of the GNU General
+ *  Public License, version 2.
+ */
+
+#include <getopt.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+#define BLKELVGET   _IO(0x12,106)/* elevator get */
+#define BLKELVSET   _IO(0x12,107)/* elevator set */
+
+/* this has to match with the kernel structure */
+typedef struct blkelv_ioctl_arg_s {
+	void * queue_ID;
+	int read_latency;
+	int write_latency;
+	int max_bomb_segments;
+} blkelv_ioctl_arg_t;
+
+static void
+usage(void) {
+	fprintf(stderr, "usage:\n\telvtune [-r r_lat] [-w w_lat] [-b b_lat] /dev/blkdev1 [/dev/blkdev2...]\n");
+	fprintf(stderr, "\telvtune -h\n");
+	fprintf(stderr, "\telvtune -v\n");
+}
+
+static void
+version(void) {
+	fprintf(stderr, "elvtune: version 1.0\n");
+}
+
+int
+main(int argc, char * argv[]) {
+	int read_value = 0xbeefbeef, write_value = 0xbeefbeef, bomb_value = 0xbeefbeef;
+	int read_set, write_set, bomb_set, set;
+	char * devname;
+	int fd;
+	blkelv_ioctl_arg_t elevator;
+
+	read_set = write_set = bomb_set = set = 0;
+
+	for (;;) {
+		int opt;
+
+		opt = getopt(argc, argv, "r:w:b:hv");
+		if (opt < 0)
+			break;
+		switch (opt) {
+		case 'r':
+			read_value = atoi(optarg);
+			read_set = set = 1;
+			break;
+		case 'w':
+			write_value = atoi(optarg);
+			write_set = set = 1;
+			break;
+		case 'b':
+			bomb_value = atoi(optarg);
+			bomb_set = set = 1;
+			break;
+
+		case 'h':
+			usage(), exit(0);
+		case 'v':
+			version(), exit(0);
+
+		case '?':
+		default:
+		case ':':
+			fprintf(stderr, "parse error\n");
+			exit(1);
+		}
+	}
+
+	if (optind >= argc)
+		fprintf(stderr, "missing blockdevice, use -h for help\n"), exit(1);
+		
+	while (optind < argc) {
+		devname = argv[optind++];
+
+		fd = open(devname, O_RDONLY|O_NONBLOCK);
+		if (fd < 0) {
+			perror("open");
+			break;
+		}
+
+		if (ioctl(fd, BLKELVGET, &elevator) < 0) {
+			perror("ioctl get");
+			break;
+		}
+
+		if (set) {
+			if (read_set)
+				elevator.read_latency = read_value;
+			if (write_set)
+				elevator.write_latency = write_value;
+			if (bomb_set)
+				elevator.max_bomb_segments = bomb_value;
+
+			if (ioctl(fd, BLKELVSET, &elevator) < 0) {
+				perror("ioctl set");
+				break;
+			}
+			if (ioctl(fd, BLKELVGET, &elevator) < 0) {
+				perror("ioctl reget");
+				break;
+			}
+		}
+
+		printf("\n%s elevator ID %p\n", devname, elevator.queue_ID);
+		printf("\tread_latency:\t\t%d\n", elevator.read_latency);
+		printf("\twrite_latency:\t\t%d\n", elevator.write_latency);
+		printf("\tmax_bomb_segments:\t%d\n\n", elevator.max_bomb_segments);
+
+		if (close(fd) < 0) {
+			perror("close");
+			break;
+		}
+	}
+
+	return 0;
+}