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

Zswap Merged Into The Linux 3.11 Kernel

Free Software

Published on 11 July 2013 01:31 AM EDT
Written by Michael Larabel in Free Software
10 Comments

Zswap is a feature for the Linux kernel that provides compressed swap caching. It's been in development for a long time and was finally merged into the mainline Linux kernel for the 3.11 release.

Making the Linux 3.11 kernel an even more exciting release was the merger on Wednesday of the Zswap support. Per the Linux kernel documentation, "Zswap is a lightweight compressed cache for swap pages. It takes pages that are in the process of being swapped out and attempts to compress them into a dynamically allocated RAM-based memory pool. zswap basically trades CPU cycles for potentially reduced swap I/O. This trade-off can also result in a significant performance improvement if reads from the compressed cache are faster than reads from a swap device."

Among potentially beneficial scenarios are desktop/laptops with limited RAM, overcommitted virtualization guests sharing common I/O resources, and users with SSDs as swap devices can extend their devices life by shortening writes. With the Kconfig ZSWAP support for Zswap enabled, it's just a matter of setting zswap.enabled=1 as a kernel module parameter.

As part of the Zswap work, Zbud was also added to the kernel tree for 3.11. Zbud is a special purpose memory allocator for storing compressed pages. This allocator is a rewrite of the Zbud code found in Zcache.

The merge to mainline of Zswap happened with this commit. "Zswap is a thin backend for frontswap that takes pages that are in the process of being swapped out and attempts to compress them and store them in a RAM-based memory pool."

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. Scythe Mugen MAX
  2. Intel Core i7 5960X Haswell-E On Linux
  3. Intel 80GB 530 Series M.2 SSD On Linux
  4. With A New Motherboard, The Core i7 5960X Haswell-E Lights Up
Latest Linux Articles
  1. RadeonSI Gallium3D vs. Catalyst At 4K UHD On Linux
  2. MSAA RadeonSI Gallium3D Performance Preview
  3. Intel Core i7 5960X CPU Core Scaling Under Linux
  4. AMD RadeonSI Gallium3D Performance For 4K Linux Gaming
Latest Linux News
  1. Tropico 5 Being Released For Linux Gamers This Week
  2. Eclipse IDE Starts Firing Up On Wayland's Weston
  3. OpenSUSE Announcement On SUSE's Recent Merger
  4. Valve Begins Publicly Tracking AMD Catalyst Linux Issues
  5. Digia Qt Spinoff Is Called "The Qt Company"
  6. GNOME 3.14 Makes More Progress In Running Natively On Wayland
  7. Minix 3.3 Released With Cortex-A8 ARM Support, NetBSD Userland Compatibility
  8. More Intel DRM Changes Queued For Linux 3.18, Including Old i830M Fixes
  9. New Code Starts Lining Up For X.Org Server 1.17
  10. Rust Developers Planning For The Rust 1.0 Language
Latest Forum Discussions
  1. Hd 6850
  2. New stress testing utility for GPU's
  3. New Group Calls For Boycotting Systemd
  4. Best Radeon for a Power Mac G5?
  5. Updated and Optimized Ubuntu Free Graphics Drivers
  6. support for first generation UVD blocks (RV6xx, RS780, RS880 and RV790)
  7. Nvidia joins the ranks of Apple and Microsoft
  8. nv and xorg.conf under Debian PPC