1. Computers
  2. Display Drivers
  3. Graphics Cards
  4. Memory
  5. Motherboards
  6. Processors
  7. Software
  8. Storage
  9. Operating Systems


Facebook RSS Twitter Twitter Google Plus


Phoronix Test Suite

OpenBenchmarking.org

Speed Boost: The Linux Kernel Can Run On Zero CPU Cores

Linux Kernel

Published on 02 April 2012 10:04 AM EDT
Written by Michael Larabel in Linux Kernel
9 Comments

A patch emerged out of IBM yesterday so that the Linux kernel can now has optimal SMP efficiency by being able to support running off zero CPU cores.

From Paul E. McKenney's mailing list message, "Although there have been numerous complaints about the complexity of parallel programming (especially over the past 5-10 years), the plain truth is that the incremental complexity of parallel programming over that of sequential programming is not as large as is commonly believed. Despite that you might have heard, the mind-numbing complexity of modern computer systems is not due so much to there being multiple CPUs, but rather to there being any CPUs at all. In short, for the ultimate in computer-system simplicity, the optimal choice is NR_CPUS=0. This commit therefore limits kernel builds to zero CPUs. This change has the beneficial side effect of rendering all kernel bugs harmless. Furthermore, this commit enables additional beneficial changes, for example, the removal of those parts of the kernel that are not needed when there are zero CPUs."

It's only about a 100 line article and covers Alpha, ARM, Blackfin, Hexagon, IA64, M32R, MIPS, MN10300, Parisc, PowerPC, S390, SPARC, TILE, and x86 architectures. The kernel config for the option now mentions zero CPUs will give you "ultimate reliability" and "minimize both memory footprint and bugs" and "Debloating is the way, NR_CPUS to zero today!!!"

Among the kernel developers commenting was AMD's Borislav Petkov who has confirmed this will work with AMD's upcoming CPU having zero CPU cores.

Before getting too worked up... Yes, this was an April Fools' Day kernel joke, unlike the Valve Linux stuff actually going down.

About The Author
Michael Larabel is the principal author of Phoronix.com and founded the web-site in 2004 with a focus on enriching the Linux hardware experience and being the largest web-site devoted to Linux hardware reviews, particularly for products relevant to Linux gamers and enthusiasts but also commonly reviewing servers/workstations and embedded Linux devices. Michael has written more than 10,000 articles covering the state of Linux hardware support, Linux performance, graphics hardware drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated testing software. He can be followed via and or contacted via .
Latest Linux Hardware Reviews
  1. AMD Launches New FX CPUs, Cuts Prices On Existing Processors
  2. Preview: AMD's FX-9590 Eight-Core At Up To 5.0GHz On Linux
  3. Intel Launches The Core i7 5960X, Mighty Powerful Haswell-E CPUs
  4. AMD Radeon R9 290: Gallium3D vs. Catalyst Drivers
Latest Linux Articles
  1. Ondemand vs. Performance CPU Governing For AMD FX CPUs On Linux 3.17
  2. How Intel Graphics On Linux Compare To Open-Source AMD/NVIDIA Drivers
  3. The Fastest NVIDIA GPUs For Open-Source Nouveau With Steam Linux Gaming
  4. Testing For The Latest Linux Kernel Power Regression
Latest Linux News
  1. The Witcher 2 Ups The Performance More & Works Around Catalyst Bug
  2. Running Gallium3D's LLVMpipe On The Eight-Core 5GHz CPU
  3. Trying Intel OpenCL On Linux For Video Encoding
  4. GSoC 2014 Yielded Some Improvements For Mesa/X.Org This Year
  5. webOS Lives On As LuneOS With New Release
  6. Marek Lands Radeon Gallium3D HyperZ Improvements
  7. Mozilla Firefox 32 Surfaces With HTML5, Developer Changes
  8. Nouveau X.Org Driver Released With DRI3+Present, Maxwell, GLAMOR
  9. Microsoft & AMD Release C++ AMP Compiler With Linux Support
  10. AMD, Wine & Valve Dominated August For Linux Users
Latest Forum Discussions
  1. Lennart Poettering Talks Up His New Linux Vision That Involves Btrfs
  2. nv and xorg.conf under Debian PPC
  3. AMD graphics doesn't work with AMD Catalyst drivers
  4. Best Radeon for a Power Mac G5?
  5. The dangers of Linux kernel development
  6. Updated and Optimized Ubuntu Free Graphics Drivers
  7. AMD Releases UVD Video Decode Support For R600 GPUs
  8. SSD seems slow