also, any limitations with experimenting with softdog on x86_64?

[Robert P. J. Day]

admittedly kind of a kernel question but in preparation for playing
with software watchdog on a powerpc target, are there any limitations
related to setting up softdog on my x86_64 laptop running fedora 23?

i just want to experiment -- would there be any significant
differences in how the software watchdog works based on the underlying
architecture?

again, thanks.

rday

[stan]

On Sat, 15 Oct 2016 05:08:31 -0400 (EDT)
"Robert P. J. Day"  wrote:
> admittedly kind of a kernel question but in preparation for playing
> with software watchdog on a powerpc target, are there any limitations
> related to setting up softdog on my x86_64 laptop running fedora 23?
>
> i just want to experiment -- would there be any significant
> differences in how the software watchdog works based on the underlying
> architecture?

caveat:  The first I heard of watchdog was your post

You are probably aware of the documentation about watchdog in the
kernel source.

$ rpmbuild/BUILD/kernel-4.8.fc25/linux-4.9.0-0.rc0.git4.1.20161010.fc25.x86_64/Documentation/watchdog
total 76
-rw-r--r--. 3 9999 9999  7632 Oct  2 16:24 convert_drivers_to_kernel_api.txt
-rw-r--r--. 3 9999 9999  3901 Oct  2 16:24 hpwdt.txt
-rw-r--r--. 3 9999 9999    16 Oct  2 16:24 Makefile
-rw-r--r--. 3 9999 9999  2266 Oct  2 16:24 pcwd-watchdog.txt
drwxr-xr-x. 2 9999 9999  4096 Oct 10 17:36 src
-rw-r--r--. 3 9999 9999  8444 Oct  2 16:24 watchdog-api.txt
-rw-r--r--. 3 9999 9999 14091 Oct  2 16:24 watchdog-kernel-api.txt
-rw-r--r--. 3 9999 9999 17712 Oct  2 16:24 watchdog-parameters.txt
-rw-r--r--. 3 9999 9999  1825 Oct  2 16:24 wdt.txt

In watchdog-parameters.txt

softdog:
soft_margin: Watchdog soft_margin in seconds.
        (0 < soft_margin < 65536, default=60)
nowayout: Watchdog cannot be stopped once started
        (default=kernel config parameter)
soft_noboot: Softdog action, set to 1 to ignore reboots, 0 to reboot
        (default=0)

As far as being compatible with PPC, there is talk about the NMI in the
above documentation, and I don't know whether PPC has this.  That is,
it might work the same at a high level, but it would have to be
different under the covers.

Because I build custom kernels, and don't enable any of the watchdog
modules, I don't have the dev/watchdog* files you mention in your other
post.  That implies to me that it is the kernel requesting the creation
of those files, based on driver modules it loads.

$ cat /boot/config-4.9.0-0.rc0.git4.1.20161010.fc25.x86_64 | grep -i watchdog
CONFIG_CLOCKSOURCE_WATCHDOG=y
# CONFIG_DPM_WATCHDOG is not set
CONFIG_ACPI_WATCHDOG=y
CONFIG_WATCHDOG=y
CONFIG_WATCHDOG_CORE=y
# CONFIG_WATCHDOG_NOWAYOUT is not set
# CONFIG_WATCHDOG_SYSFS is not set
# Watchdog Device Drivers
# CONFIG_SOFT_WATCHDOG is not set
# CONFIG_XILINX_WATCHDOG is not set
# CONFIG_ZIIRAVE_WATCHDOG is not set
# CONFIG_CADENCE_WATCHDOG is not set
# CONFIG_DW_WATCHDOG is not set
# CONFIG_MAX63XX_WATCHDOG is not set
# CONFIG_SBC_FITPC2_WATCHDOG is not set
# CONFIG_HP_WATCHDOG is not set
# CONFIG_SBC_EPX_C3_WATCHDOG is not set
# PCI-based Watchdog Cards
# CONFIG_PCIPCWATCHDOG is not set
# USB-based Watchdog Cards
# CONFIG_USBPCWATCHDOG is not set
# CONFIG_WQ_WATCHDOG is not set