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

BCache For The Linux Kernel Still Being Tackled

Linux Kernel

Published on 10 May 2012 09:33 PM EDT
Written by Michael Larabel in Linux Kernel
6 Comments

BCache for the Linux kernel is still being worked on and is now up to its thirteenth revision prior to being merged into the mainline Linux kernel. BCache provides write-through and write-back caching as a new block device.

From the latest BCache patches that hit the Linux kernel mailing list on Wednesday, here's the description of this new kernel caching mechanism for Linux:
Bcache does both writethrough and writeback caching. It presents itself as a new block device, a bit like say md. You can cache an arbitrary number of block devices with a single cache device, and attach and detach things at runtime - it's quite flexible.

It's very fast. It uses a b+ tree for the index, along with a journal to coalesce index updates, and a bunch of other cool tricks like auxiliary binary search trees with software floating point keys for searching within btreenodes.

Bcache is solid, production ready code. There are still bugs being found that affect specific configurations, but there haven't been any major issues found in awhile - it's well past time I started working on getting it into mainline.

It's a lot of code - I tried to split it out so that it'd make some sort of sense for reviewing. Let me know if there's anything else I can do to make review easier.
The work is fairly in-depth and spread across 16 patches now up to their 13th revision prior to mainline inclusion. Will the 13th time be the charm and be set for inclusion into the Linux 3.5 kernel? Only time will tell, but from their TODO list: "The userspace interface is going to change before it goes in. The general consensus at LSF was that we don't want yet another interface for probing/managing block devices, and dm exists so we may as well use that. I don't think anyone's started on that yet, though." With user-space breakage, BCache might still be a ways off from hitting the mainline tree.

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. MSI X99S SLI PLUS On Linux
  2. NVIDIA GeForce GTX 970 Offers Great Linux Performance
  3. CompuLab Intense-PC2: An Excellent, Fanless, Mini PC Powered By Intel's i7 Haswell
  4. From The Atom 330 To Haswell ULT: Intel Linux Performance Benchmarks
Latest Linux Articles
  1. RunAbove: A POWER8 Compute Cloud With Offerings Up To 176 Threads
  2. 6-Way Ubuntu 14.10 Linux Desktop Benchmarks
  3. Ubuntu 14.10 XMir System Compositor Benchmarks
  4. Btrfs RAID HDD Testing On Ubuntu Linux 14.10
Latest Linux News
  1. Fedora 21 Beta & Final Release Slip Further
  2. Mesa 10.3.2 Has A Couple Bug-Fixes
  3. RadeonSI/R600g HyperZ Support Gets Turned Back On
  4. openSUSE Factory & Tumbleweed Are Merging
  5. More Fedora Delays: Fedora 21 Beta Slips
  6. Mono Brings C# To The Unreal Engine 4
  7. Coreboot Now Has Support For Intel Broadwell Hardware
  8. Enlightenment's EFL 1.12 Alpha Has Evas GL-DRM Engine, OpenGL ES 1.1 Support
  9. GTK+ Lands Experimental Backend For Mir Display Server
  10. Ubuntu 14.10 Officially Released
Latest Forum Discussions
  1. AMD Radeon VDPAU Video Performance With Gallium3D
  2. HOPE: The Ease Of Python With The Speed Of C++
  3. Updated and Optimized Ubuntu Free Graphics Drivers
  4. Ubuntu 16.04 Might Be The Distribution's Last 32-Bit Release
  5. Linux hacker compares Solaris kernel code:
  6. Advertisements On Phoronix
  7. Users/Developers Threatening Fork Of Debian GNU/Linux
  8. AMD Releases UVD Video Decode Support For R600 GPUs