Under the hood JVM: Safepoints

• A safepoint is a range of execution where the state of the executing thread is well described. Safepoints…

Under the hood definitions: Memory model and memory barriers

What is a memory model

Under the hood CPU Utilization, CPI and Load Averages

What really is CPU Utilization?

The metric we call CPU utilization is really “non-idle time”: the time the CPU was not running the idle thread. Your operating system kernel (whatever it is)…

Under the hood OS: Demand Paging, Page Faults and Working Set

Linux is an on demand memory system. The malloc() call immediately returns virtual memory, which is only promoted to real memory later when it is used via a page fault.

Demand Paging

Under the hood system calls : Debugging, INT, SIGTRAP

Ever wondered how debuggers work?? Gdb, strace, …etc…Here is more about them and why you should not use them in production facing systems!

SIGTRAP

Signal         Value   Action…

Under the hood CPU: Know your CPU

know the mechanics of your race car, part 1: CPU

Terminology used

Under the hood memory: Know your memory(and caches!)

Random Access Memory(RAM)

Under the hood attacks: Spectre and Meltdown

taken with permission of the author from…