What is TSC clocksource?

The TSC is the preferred clocksource between the two counters, as it is the fastest one, however it can only be used if it is stable. Currently there are 4 types of TSC present: Constant. Constant TSC means that the TSC does not change with CPU frequency changes, however it does change on C state transitions.

What is Linux TSC?

This is a counter implemented in every x86 microprocessor by means of a 64-bit register called TSC the register. It counts the number of clock signals arriving on the CLK pin of the processor. The current counter value can be read by accessing the TSC register.

What is HPET Linux?

The High Precision Event Timer (HPET) hardware follows a specification by Intel and Microsoft, revision 1. Each HPET has one fixed-rate counter (at 10+ MHz, hence “High Precision”) and up to 32 comparators. HPET devices can support two interrupt routing modes. …

What is invariant TSC?

The invariant TSC means that the TSC continues at a fixed rate regardless of the C-state or frequency of the processor (as long as the processor remains in the ACPI S0 state).

What is Jiffies in Linux kernel?

The global variable “jiffies” holds the number of ticks that have occurred since the system booted. On boot, the kernel initializes the variable to zero, and it is incremented by one during each timer interrupt. Thus, because there are HZ timer interrupts in a second, there are HZ jiffies in a second.

What is TSC sync?

Basically, it’s the OS’ job, at boot time, to synchronize the TSC counters between all the different processors and/or cores on an SMP machine, within a certain margin of error.

What is Dev HPET?

HPET, or High Precision Event Timer, is a piece of hardware designed by Intel and Microsoft to replace older PIT and RTC. It consists of (usually 64-bit) main counter (which counts up), as well as from 3 to 32 32-bit or 64-bit wide comparators.

What is HPET mode?

The HPET Mode BIOS option is linked to the HPET Support BIOS option. The HPET, short for High Precision Event Timer, is a new system timer developed by Intel and Microsoft to replace the four system timers currently in use. Some HPETs have 64-bits wide registers which can also run in the 32-bit mode.

What is kernel and advantages and disadvantages?

It provides CPU scheduling, memory management, file management and other operating system functions through system calls. The other one is that it is a single large process running entirely in a single address space. It is a single static binary file.

What of the following is one of the disadvantages of having a monolithic kernel like Linux?

Disadvantages of Monolithic Kernel –

• One of the major disadvantages of a monolithic kernel is that if anyone service fails it leads to an entire system failure.
• If the user has to add any new service. The user needs to modify the entire operating system.

What is Clflush?

CLFLUSH m8. Flushes cache line containing m8. Description. Invalidates the cache line that contains the linear address specified with the source operand from all levels of the processor cache hierarchy (data and instruction).