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Commit 9f2fa466 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

Merge branch 'master' of /home/trondmy/kernel/linux-2.6/

parents 607f31e8 0a6047ee
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+10 −0
Original line number Diff line number Diff line
@@ -177,6 +177,16 @@ Who: Jean Delvare <khali@linux-fr.org>

---------------------------

What:	Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
	(temporary transition config option provided until then)
	The transition config option will also be removed at the same time.
When:	before 2.6.19
Why:	Unused symbols are both increasing the size of the kernel binary
	and are often a sign of "wrong API"
Who:	Arjan van de Ven <arjan@linux.intel.com>

---------------------------

What:	remove EXPORT_SYMBOL(tasklist_lock)
When:	August 2006
Files:	kernel/fork.c
+3 −72
Original line number Diff line number Diff line
@@ -22,78 +22,9 @@
 to run the program with an "&" to run it in the background!)

 If you want to write a program to be compatible with the PC Watchdog
 driver, simply do the following:

-- Snippet of code --
/*
 * Watchdog Driver Test Program
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <linux/watchdog.h>

int fd;

/*
 * This function simply sends an IOCTL to the driver, which in turn ticks
 * the PC Watchdog card to reset its internal timer so it doesn't trigger
 * a computer reset.
 */
void keep_alive(void)
{
    int dummy;

    ioctl(fd, WDIOC_KEEPALIVE, &dummy);
}

/*
 * The main program.  Run the program with "-d" to disable the card,
 * or "-e" to enable the card.
 */
int main(int argc, char *argv[])
{
    fd = open("/dev/watchdog", O_WRONLY);

    if (fd == -1) {
	fprintf(stderr, "Watchdog device not enabled.\n");
	fflush(stderr);
	exit(-1);
    }

    if (argc > 1) {
	if (!strncasecmp(argv[1], "-d", 2)) {
	    ioctl(fd, WDIOC_SETOPTIONS, WDIOS_DISABLECARD);
	    fprintf(stderr, "Watchdog card disabled.\n");
	    fflush(stderr);
	    exit(0);
	} else if (!strncasecmp(argv[1], "-e", 2)) {
	    ioctl(fd, WDIOC_SETOPTIONS, WDIOS_ENABLECARD);
	    fprintf(stderr, "Watchdog card enabled.\n");
	    fflush(stderr);
	    exit(0);
	} else {
	    fprintf(stderr, "-d to disable, -e to enable.\n");
	    fprintf(stderr, "run by itself to tick the card.\n");
	    fflush(stderr);
	    exit(0);
	}
    } else {
	fprintf(stderr, "Watchdog Ticking Away!\n");
	fflush(stderr);
    }

    while(1) {
	keep_alive();
	sleep(1);
    }
}
-- End snippet --
 driver, simply use of modify the watchdog test program:
 Documentation/watchdog/src/watchdog-test.c


 Other IOCTL functions include:

+15 −0
Original line number Diff line number Diff line
#include <stdlib.h>
#include <fcntl.h>

int main(int argc, const char *argv[]) {
	int fd = open("/dev/watchdog", O_WRONLY);
	if (fd == -1) {
		perror("watchdog");
		exit(1);
	}
	while (1) {
		write(fd, "\0", 1);
		fsync(fd);
		sleep(10);
	}
}
+68 −0
Original line number Diff line number Diff line
/*
 * Watchdog Driver Test Program
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <linux/watchdog.h>

int fd;

/*
 * This function simply sends an IOCTL to the driver, which in turn ticks
 * the PC Watchdog card to reset its internal timer so it doesn't trigger
 * a computer reset.
 */
void keep_alive(void)
{
    int dummy;

    ioctl(fd, WDIOC_KEEPALIVE, &dummy);
}

/*
 * The main program.  Run the program with "-d" to disable the card,
 * or "-e" to enable the card.
 */
int main(int argc, char *argv[])
{
    fd = open("/dev/watchdog", O_WRONLY);

    if (fd == -1) {
	fprintf(stderr, "Watchdog device not enabled.\n");
	fflush(stderr);
	exit(-1);
    }

    if (argc > 1) {
	if (!strncasecmp(argv[1], "-d", 2)) {
	    ioctl(fd, WDIOC_SETOPTIONS, WDIOS_DISABLECARD);
	    fprintf(stderr, "Watchdog card disabled.\n");
	    fflush(stderr);
	    exit(0);
	} else if (!strncasecmp(argv[1], "-e", 2)) {
	    ioctl(fd, WDIOC_SETOPTIONS, WDIOS_ENABLECARD);
	    fprintf(stderr, "Watchdog card enabled.\n");
	    fflush(stderr);
	    exit(0);
	} else {
	    fprintf(stderr, "-d to disable, -e to enable.\n");
	    fprintf(stderr, "run by itself to tick the card.\n");
	    fflush(stderr);
	    exit(0);
	}
    } else {
	fprintf(stderr, "Watchdog Ticking Away!\n");
	fflush(stderr);
    }

    while(1) {
	keep_alive();
	sleep(1);
    }
}
+39 −17
Original line number Diff line number Diff line
@@ -34,22 +34,7 @@ activates as soon as /dev/watchdog is opened and will reboot unless
the watchdog is pinged within a certain time, this time is called the
timeout or margin.  The simplest way to ping the watchdog is to write
some data to the device.  So a very simple watchdog daemon would look
like this:

#include <stdlib.h>
#include <fcntl.h>

int main(int argc, const char *argv[]) {
	int fd=open("/dev/watchdog",O_WRONLY);
	if (fd==-1) {
		perror("watchdog");
		exit(1);
	}
	while(1) {
		write(fd, "\0", 1);
		sleep(10);
	}
}
like this source file:  see Documentation/watchdog/src/watchdog-simple.c

A more advanced driver could for example check that a HTTP server is
still responding before doing the write call to ping the watchdog.
@@ -110,7 +95,40 @@ current timeout using the GETTIMEOUT ioctl.
    ioctl(fd, WDIOC_GETTIMEOUT, &timeout);
    printf("The timeout was is %d seconds\n", timeout);

Envinronmental monitoring:
Pretimeouts:

Some watchdog timers can be set to have a trigger go off before the
actual time they will reset the system.  This can be done with an NMI,
interrupt, or other mechanism.  This allows Linux to record useful
information (like panic information and kernel coredumps) before it
resets.

    pretimeout = 10;
    ioctl(fd, WDIOC_SETPRETIMEOUT, &pretimeout);

Note that the pretimeout is the number of seconds before the time
when the timeout will go off.  It is not the number of seconds until
the pretimeout.  So, for instance, if you set the timeout to 60 seconds
and the pretimeout to 10 seconds, the pretimout will go of in 50
seconds.  Setting a pretimeout to zero disables it.

There is also a get function for getting the pretimeout:

    ioctl(fd, WDIOC_GETPRETIMEOUT, &timeout);
    printf("The pretimeout was is %d seconds\n", timeout);

Not all watchdog drivers will support a pretimeout.

Get the number of seconds before reboot:

Some watchdog drivers have the ability to report the remaining time
before the system will reboot. The WDIOC_GETTIMELEFT is the ioctl
that returns the number of seconds before reboot.

    ioctl(fd, WDIOC_GETTIMELEFT, &timeleft);
    printf("The timeout was is %d seconds\n", timeleft);

Environmental monitoring:

All watchdog drivers are required return more information about the system,
some do temperature, fan and power level monitoring, some can tell you
@@ -169,6 +187,10 @@ The watchdog saw a keepalive ping since it was last queried.

	WDIOF_SETTIMEOUT	Can set/get the timeout

The watchdog can do pretimeouts.

	WDIOF_PRETIMEOUT	Pretimeout (in seconds), get/set


For those drivers that return any bits set in the option field, the
GETSTATUS and GETBOOTSTATUS ioctls can be used to ask for the current
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