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Image of Modern Operating Systems (3rd Edition)
Image of Linux Kernel Development (3rd Edition)
Image of Operating System Concepts
Image of Advanced Programming in the UNIX Environment, Second Edition (Addison-Wesley Professional Computing Series)

Nesting RHEL7 KVM on VMware Workstation 12

In this post I discuss how to enable a Red Hat Enterprise Linux VM to use KVM when installed on top of VMware Workstation version 8 or later.

Korn Shell Launcher for Windows Subsystem for Linux

In this post, I show you how to create a Korn Shell launcher for the new Windows Subsystem for Linux.

What is /proc/config.gz?

Linux can store a gzip’ed copy of the kernel configuration file used to build the kernel in the kernel itself, and make it available to users via /proc/config.gz. This file is not always present in a Linux distribution. It is only present when /proc support is enabled and CONFIG_IKCONFIG and CONFIG_IKCONFIG_PROC are set to Y in the kernel configuration file. Most distributions do not enable it by default; instead they include the kernel configuration file under /boot. If in-kernel configuration support is built as a kernel module, then before you can use /proc/config.gz, the configs module needs to be loaded

Intel Processor Power Management

Modern Intel processor power management is based on a combination of two techniques: changing the CPU frequency (P-states) and using idling power states (C-states). A third technique, used on older processors but rarely on modern processors, is throttling of the CPU (T-states). P-states are voltage-frequency pairs that set the speed and power consumption of an Intel processor. When the operating voltage of the processor is lower, so is the power consumption. C-states are idle power saving states, in contrast to P-states, which are execution power saving states. During a P-state, the processor is still executing instructions, whereas during a C-state

On-disk File Timestamps

The Single Unix Specification, Base Definitions (XBD), Section 4.8 entitled “File Times Update” states “An implementation may update timestamps that are marked for update immediately, or it may update such timestamps periodically.” This means that, for example, that file read and write operations are free to set the appropriate flags in the in-memory structures and do the actual updating of the on-disk filesystem structures at a later time. Assuming periodically means from time to time, it implies that a POSIX-compliant operating system is free to update it’s on-disk structures when it is convenient for the operating system to do so.