On 11/18/19 7:09 AM, Muni Sekhar wrote:
On Mon, Nov 18, 2019 at 8:08 PM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
[-cc linux-pci (nothing here is PCI-specific)]
On Sat, Nov 16, 2019 at 06:05:05AM +0530, Muni Sekhar wrote:
My kernel is built with the following options:
$ cat /boot/config-5.0.1 | grep NO_HZ
CONFIG_NO_HZ_COMMON=y
CONFIG_NO_HZ_IDLE=y
# CONFIG_NO_HZ_FULL is not set
CONFIG_NO_HZ=y
CONFIG_RCU_FAST_NO_HZ=y
I booted with watchdog enabled(nmi_watchdog=1) as given below:
BOOT_IMAGE=/boot/vmlinuz-5.0.1
root=UUID=f65454ae-3f1d-4b9e-b4be-74a29becbe1e ro debug
ignore_loglevel console=ttyUSB0,115200 console=tty0 console=tty1
console=ttyS2,115200 memmap=1M!1023M nmi_watchdog=1
crashkernel=384M-:128M
When the system is frozen or the kernel is locked up(I noticed that in
this state kernel is not responding for ALT-SysRq-<command key>) but
watchdog is not triggered. So I want to understand how to enable the
watchdog timer and how to verify the basic watchdog functionality
behavior?
I don't know much about the watchdog, but I assume you've found these
already?
Documentation/admin-guide/lockup-watchdogs.rst
Documentation/admin-guide/sysctl/kernel.rst
Do you have CONFIG_HAVE_NMI_WATCHDOG=y? (See arch/Kconfig)
I don’t have CONFIG_HAVE_NMI_WATCHDOG in kernel .config file.
That would mean you don't have NMI in the first place. What is your
architecture ?
Guenter
$cat /boot/config-5.0.1 | grep CONFIG_HAVE_NMI_WATCHDOG
But tried to enable CONFIG_HAVE_NMI_WATCHDOG via menuconfig, but could
not able to find it. What is the role of CONFIG_HAVE_NMI_WATCHDOG?
Symbol: HAVE_NMI_WATCHDOG [=n]
│
│ Type : bool
│
│ Defined at arch/Kconfig:339
│
│ Depends on: HAVE_NMI [=y]
│
│ Selected by [n]:
│
│ - HAVE_HARDLOCKUP_DETECTOR_ARCH [=n]
│ Symbol: HAVE_HARDLOCKUP_DETECTOR_ARCH [=n]
│
│ Type : bool
│
│ Defined at arch/Kconfig:346
│
│ Selects: HAVE_NMI_WATCHDOG [=n]
