What is NMI watchdog bug soft lockup?

A ‘soft lockup’ is defined as a bug that causes the kernel to loop in kernel mode for more than 20 seconds without giving other tasks a chance to run. The watchdog daemon will send an non-maskable interrupt (NMI) to all CPUs in the system who, in turn, print the stack traces of their currently running tasks.

What causes soft lockup?

A soft lockup is the symptom of a task or kernel thread using and not releasing a CPU for a longer period of time than allowed. The technical reason behind a soft lock involves CPU interrupts and nmi-watchdog. For each online CPU on the system, a watchdog process gets created.

What is Watchdog_thresh?

watchdog_thresh. This value is used to set the frequency of hrtimer and NMI events and the soft and hard lockup thresholds. The default threshold is 10 seconds.

What is hard lockup on CPU?

A ‘hard lockup’ is defined as a bug that causes the CPU to loop in kernel mode for more than 10 seconds […], without letting other interrupts have a chance to run. In other words, during a soft lockup a kernel task won’t unlock the CPU, like in the good old DOS days.

How do I turn off NMI watchdog?

Disable NMI: You can only run this command which kernel version is 2.6. 18–238 and later. Otherwise you have to edit grub. conf then reboot server to disable NMI watchdog.

Where is Sysctl?

/proc/sys/
DESCRIPTION top. sysctl is used to modify kernel parameters at runtime. The parameters available are those listed under /proc/sys/.

What is soft lockup hedge fund?

A soft lock-up works much like a hard lock-up, but with one key difference: an investor can redeem during the soft lock-up period by paying a redemption penalty to the fund.

How do I block watchdog?

Disable the Linux kernel watchdog

1. Add nowatchdog and/or nmi_watchdog=0 to your kernel command line (info).
2. Additionally blacklist these modules by creating a /etc/modprobe.d/*.conf file: blacklist iTCO_wdt blacklist iTCO_vendor_support.
3. Additionally edit/create a file like this: echo ‘kernel.

What is NMI panic Linux?

Non-Maskable Interrupt(NMI) is the highest priority interrupt that can not be masked by any software. Basically, this is the scenario when you press CTRL+ALT+DELETE on Windows computer.

What does sysctl stand for?

sysctl is a software utility of some Unix-like operating systems that reads and modifies the attributes of the system kernel such as its version number, maximum limits, and security settings. It is available both as a system call for compiled programs, and an administrator command for interactive use and scripting.

What happens when a stock lockup expires?

When IPO lockups expire, insiders tend to sell a portion of their shares. Because of the increase in supply, the share price may drop. In anticipation of this event, many investors will sell their shares in the days leading up to the expiration date to get ahead of the drop.