cregit-Linux how code gets into the kernel

Release 4.7 Documentation/laptops/dslm.c

/*
 * dslm.c
 * Simple Disk Sleep Monitor
 *  by Bartek Kania
 * Licensed under the GPL
 */
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include <time.h>
#include <string.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <linux/hdreg.h>

#ifdef DEBUG

#define D(x) x
#else

#define D(x)
#endif


int endit = 0;

/* Check if the disk is in powersave-mode
 * Most of the code is stolen from hdparm.
 * 1 = active, 0 = standby/sleep, -1 = unknown */

static int check_powermode(int fd) { unsigned char args[4] = {WIN_CHECKPOWERMODE1,0,0,0}; int state; if (ioctl(fd, HDIO_DRIVE_CMD, &args) && (args[0] = WIN_CHECKPOWERMODE2) /* try again with 0x98 */ && ioctl(fd, HDIO_DRIVE_CMD, &args)) { if (errno != EIO || args[0] != 0 || args[1] != 0) { state = -1; /* "unknown"; */ } else state = 0; /* "sleeping"; */ } else { state = (args[2] == 255) ? 1 : 0; } D(printf(" drive state is: %d\n", state)); return state; }

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PersonTokensPropCommitsCommitProp
randy dunlaprandy dunlap128100.00%1100.00%
Total128100.00%1100.00%


static char *state_name(int i) { if (i == -1) return "unknown"; if (i == 0) return "sleeping"; if (i == 1) return "active"; return "internal error"; }

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PersonTokensPropCommitsCommitProp
randy dunlaprandy dunlap41100.00%1100.00%
Total41100.00%1100.00%


static char *myctime(time_t time) { char *ts = ctime(&time); ts[strlen(ts) - 1] = 0; return ts; }

Contributors

PersonTokensPropCommitsCommitProp
randy dunlaprandy dunlap35100.00%1100.00%
Total35100.00%1100.00%


static void measure(int fd) { time_t start_time; int last_state; time_t last_time; int curr_state; time_t curr_time = 0; time_t time_diff; time_t active_time = 0; time_t sleep_time = 0; time_t unknown_time = 0; time_t total_time = 0; int changes = 0; float tmp; printf("Starting measurements\n"); last_state = check_powermode(fd); start_time = last_time = time(0); printf(" System is in state %s\n\n", state_name(last_state)); while(!endit) { sleep(1); curr_state = check_powermode(fd); if (curr_state != last_state || endit) { changes++; curr_time = time(0); time_diff = curr_time - last_time; if (last_state == 1) active_time += time_diff; else if (last_state == 0) sleep_time += time_diff; else unknown_time += time_diff; last_state = curr_state; last_time = curr_time; printf("%s: State-change to %s\n", myctime(curr_time), state_name(curr_state)); } } changes--; /* Compensate for SIGINT */ total_time = time(0) - start_time; printf("\nTotal running time: %lus\n", curr_time - start_time); printf(" State changed %d times\n", changes); tmp = (float)sleep_time / (float)total_time * 100; printf(" Time in sleep state: %lus (%.2f%%)\n", sleep_time, tmp); tmp = (float)active_time / (float)total_time * 100; printf(" Time in active state: %lus (%.2f%%)\n", active_time, tmp); tmp = (float)unknown_time / (float)total_time * 100; printf(" Time in unknown state: %lus (%.2f%%)\n", unknown_time, tmp); }

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PersonTokensPropCommitsCommitProp
randy dunlaprandy dunlap280100.00%1100.00%
Total280100.00%1100.00%


static void ender(int s) { endit = 1; }

Contributors

PersonTokensPropCommitsCommitProp
randy dunlaprandy dunlap13100.00%1100.00%
Total13100.00%1100.00%


static void usage(void) { puts("usage: dslm [-w <time>] <disk>"); exit(0); }

Contributors

PersonTokensPropCommitsCommitProp
randy dunlaprandy dunlap18100.00%1100.00%
Total18100.00%1100.00%


int main(int argc, char **argv) { int fd; char *disk = 0; int settle_time = 60; /* Parse the simple command-line */ if (argc == 2) disk = argv[1]; else if (argc == 4) { settle_time = atoi(argv[2]); disk = argv[3]; } else usage(); if (!(fd = open(disk, O_RDONLY|O_NONBLOCK))) { printf("Can't open %s, because: %s\n", disk, strerror(errno)); exit(-1); } if (settle_time) { printf("Waiting %d seconds for the system to settle down to " "'normal'\n", settle_time); sleep(settle_time); } else puts("Not waiting for system to settle down"); signal(SIGINT, ender); measure(fd); close(fd); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
randy dunlaprandy dunlap152100.00%1100.00%
Total152100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
randy dunlaprandy dunlap72399.86%150.00%
anatol pomozovanatol pomozov10.14%150.00%
Total724100.00%2100.00%
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