dslm.c

  1/*
  2 * dslm.c
  3 * Simple Disk Sleep Monitor
  4 *  by Bartek Kania
  5 * Licensed under the GPL
  6 */
  7#include <unistd.h>
  8#include <stdlib.h>
  9#include <stdio.h>
 10#include <fcntl.h>
 11#include <errno.h>
 12#include <time.h>
 13#include <string.h>
 14#include <signal.h>
 15#include <sys/ioctl.h>
 16#include <linux/hdreg.h>
 17
 18#ifdef DEBUG
 19#define D(x) x
 20#else
 21#define D(x)
 22#endif
 23
 24int endit = 0;
 25
 26/* Check if the disk is in powersave-mode
 27 * Most of the code is stolen from hdparm.
 28 * 1 = active, 0 = standby/sleep, -1 = unknown */
 29static int check_powermode(int fd)
 30{
 31    unsigned char args[4] = {WIN_CHECKPOWERMODE1,0,0,0};
 32    int state;
 33
 34    if (ioctl(fd, HDIO_DRIVE_CMD, &args)
 35	&& (args[0] = WIN_CHECKPOWERMODE2) /* try again with 0x98 */
 36	&& ioctl(fd, HDIO_DRIVE_CMD, &args)) {
 37	if (errno != EIO || args[0] != 0 || args[1] != 0) {
 38	    state = -1; /* "unknown"; */
 39	} else
 40	    state = 0; /* "sleeping"; */
 41    } else {
 42	state = (args[2] == 255) ? 1 : 0;
 43    }
 44    D(printf(" drive state is:  %d\n", state));
 45
 46    return state;
 47}
 48
 49static char *state_name(int i)
 50{
 51    if (i == -1) return "unknown";
 52    if (i == 0) return "sleeping";
 53    if (i == 1) return "active";
 54
 55    return "internal error";
 56}
 57
 58static char *myctime(time_t time)
 59{
 60    char *ts = ctime(&time);
 61    ts[strlen(ts) - 1] = 0;
 62
 63    return ts;
 64}
 65
 66static void measure(int fd)
 67{
 68    time_t start_time;
 69    int last_state;
 70    time_t last_time;
 71    int curr_state;
 72    time_t curr_time = 0;
 73    time_t time_diff;
 74    time_t active_time = 0;
 75    time_t sleep_time = 0;
 76    time_t unknown_time = 0;
 77    time_t total_time = 0;
 78    int changes = 0;
 79    float tmp;
 80
 81    printf("Starting measurements\n");
 82
 83    last_state = check_powermode(fd);
 84    start_time = last_time = time(0);
 85    printf("  System is in state %s\n\n", state_name(last_state));
 86
 87    while(!endit) {
 88	sleep(1);
 89	curr_state = check_powermode(fd);
 90
 91	if (curr_state != last_state || endit) {
 92	    changes++;
 93	    curr_time = time(0);
 94	    time_diff = curr_time - last_time;
 95
 96	    if (last_state == 1) active_time += time_diff;
 97	    else if (last_state == 0) sleep_time += time_diff;
 98	    else unknown_time += time_diff;
 99
100	    last_state = curr_state;
101	    last_time = curr_time;
102
103	    printf("%s: State-change to %s\n", myctime(curr_time),
104		   state_name(curr_state));
105	}
106    }
107    changes--; /* Compensate for SIGINT */
108
109    total_time = time(0) - start_time;
110    printf("\nTotal running time:  %lus\n", curr_time - start_time);
111    printf(" State changed %d times\n", changes);
112
113    tmp = (float)sleep_time / (float)total_time * 100;
114    printf(" Time in sleep state:   %lus (%.2f%%)\n", sleep_time, tmp);
115    tmp = (float)active_time / (float)total_time * 100;
116    printf(" Time in active state:  %lus (%.2f%%)\n", active_time, tmp);
117    tmp = (float)unknown_time / (float)total_time * 100;
118    printf(" Time in unknown state: %lus (%.2f%%)\n", unknown_time, tmp);
119}
120
121static void ender(int s)
122{
123    endit = 1;
124}
125
126static void usage(void)
127{
128    puts("usage: dslm [-w <time>] <disk>");
129    exit(0);
130}
131
132int main(int argc, char **argv)
133{
134    int fd;
135    char *disk = 0;
136    int settle_time = 60;
137
138    /* Parse the simple command-line */
139    if (argc == 2)
140	disk = argv[1];
141    else if (argc == 4) {
142	settle_time = atoi(argv[2]);
143	disk = argv[3];
144    } else
145	usage();
146
147    if (!(fd = open(disk, O_RDONLY|O_NONBLOCK))) {
148	printf("Can't open %s, because: %s\n", disk, strerror(errno));
149	exit(-1);
150    }
151
152    if (settle_time) {
153	printf("Waiting %d seconds for the system to settle down to "
154	       "'normal'\n", settle_time);
155	sleep(settle_time);
156    } else
157	puts("Not waiting for system to settle down");
158
159    signal(SIGINT, ender);
160
161    measure(fd);
162
163    close(fd);
164
165    return 0;
166}