A computer processor is described as idle when it is not being used by any program. Every program or task that runs on a computer system occupies a certain amount of processing time on the CPU. If the CPU has completed all tasks it is idle. Modern processors use idle time to save power. Common methods are reducing the clock speed along with the CPU voltage and sending parts of the processor into a sleep state. On processors that have a halt instruction that stops the CPU until an interrupt occurs, such as x86's HLT instruction, it may save significant amounts of power and heat if the idle task consists of a loop which repeatedly executes HLT instructions. Many operating systems, for example Windows, Linux, and macOS will run an idle task, which is a special task loaded by the OS scheduler on a CPU when there is nothing for the CPU to do. The idle task can be hard-coded into the scheduler, or it can be implemented as a separate task with the lowest possible priority. An advantage of the latter approach is that programs monitoring the system status can see the idle task along with all other tasks; an example is Windows NT's System Idle Process. Some programs are designed to appear to make use of CPU idle time, meaning that they run at a low priority (but slightly higher than idle priority) so as not to impact programs that run at normal priority. This allows non-crucial background programs to only run when it would not affect the performance of other applications. (Wikipedia).
Kernel Recipes 2018 - CPU Idle Loop Rework - Rafael J. Wysocki
The CPU idle loop is the piece of code executed by logical CPUs if they have no tasks to run. If the CPU supports idle states allowing it to draw less power while not executing any instructions, the idle loop invokes a CPU idle governor to select the most suitable idle state for the CPU an
From playlist Kernel Recipes 2018
Operating system for beginners || Operating system basics
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing #operating_systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation o
From playlist Operating System
The role of the hard drive buffer and interrupts when a file is transferred from primary memory (RAM) to a secondary storage device.
From playlist Computer Hardware and Architecture
Computer Basics: What Is a Computer?
Computers are all around us, and they play an important role in our lives. But what exactly is a computer? We're going to answer that question and give you an overview of some of the different types of computers you might use. 0:00 Intro 0:22 Ones and zeros 0:39 Hardware and software 1:0
From playlist Starting out with Technology
An general explanation of the underactive thyroid.
From playlist For Patients
An intro to the core protocols of the Internet, including IPv4, TCP, UDP, and HTTP. Part of a larger series teaching programming. See codeschool.org
From playlist The Internet
A short animation from me. Pretending to dock in some sort of other-worldly space station, forgetting I left the oven on, then warping back. Careless, I know!
From playlist AI Animations
Kernel Recipes 2015 - Introduction to Kernel Power Management - by Kevin Hilman
In order to keep up with the complexities of SoCs, the Linux kernel has an ever-growing set of features for power management. For the uninitiated, it can be confusing how each of these features work and even more confusing how they should work together. This talk will be a high-level intro
From playlist Kernel Recipes 2015
Kernel Recipes 2017 - Overview of Generic PM Domains (genpd) - Kevin Hilman
The generic PM domains (genpd) framework in the kernel provides a way of grouping devices together that have common power management (PM) operations. It is commonly used to represent hardware power domains (a.k.a power islands) that share a common voltage rail, but can also be used more ge
From playlist Kernel Recipes 2017
Liquid VS Air cooling for Ryzen 9 5950x in NCase M1
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From playlist Product Reviews
Stanford Seminar - KUtrace 2020
Dick Sites February 5, 2020 Observation tools for understanding occasionally-slow performance in large-scale distributed transaction systems are not keeping up with the complexity of the environment. The same applies to large database systems, to real-time control systems in cars and airp
From playlist Stanford EE380-Colloquium on Computer Systems - Seminar Series
Embedded Recipes 2019 - RT is about to make it to mainline. Now what?
The PREEMPT_RT (aka real-time patch) started back in 2004. Since then, a lot of it has made it into the kernel. The only part left is the change of turning spinning locks into mutexes, then the merge of the PREEMPT_RT patch will be complete. This is expected to happen no later than the Q1
From playlist Embedded Recipes 2019
AMD 5950x Cooling: Noctua NH-D15 is better than NZXT Kraken Z53
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From playlist Vlogs & Updates
What I use, and why (Computer, IDLE, OS...etc) - Q&A #4
In this fourth Q&A, I discuss the things I use, such as my computer, Windows, IDLE, microphone, camera, filming software...etc, and why!
From playlist Questions and Answers
Kernel Recipes 2022 - The complete story of the in-kernel sloppy GPIO logic analyzer
You know the rules, right? You should not implement a logic analyzer in software because equidistant sampling points cannot be guaranteed. You should also not disable interrupts in your kernel code, and if you really need to, it should be as short as possible. And surely you should not all
From playlist Kernel Recipes 2022
A Simple Programming Language - (part 1 of 13)
An introduction to programming with a reductively simple programming language. Part of a larger series teaching programming. Visit http://codeschool.org Please link to the playlist (http://www.youtube.com/playlist?list=PL2F1485C69B311408) rather than this video as individual videos may g
From playlist A Simple Programming Language
Writing an OS in Rust - Part 12e - A Better Executor
This is my version of Philipp Oppermann's "BlogOS". It's a baremetal operating system that can boot off of a USB stick on any BIOS-compatible machine, which is pretty amazing. I'm going to be following the whole blog, one video at a time, and running the OS using QEMU instead of booting a
From playlist Rust OS