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. A Walkthrough Of The New 32 System Open-Source Linux Benchmarking Test Farm
  2. Habey MITX-6771: Mini-ITX Board With Quad-Core J1900 Bay Trail
  3. OCZ Vector 150 SSD On Linux
  4. Noctua i4 CPU Cooler: Great For Cooling High-End LGA-2011v3 CPUs
Latest Linux Articles
  1. AMD Kaveri: Open-Source Radeon Gallium3D vs. Catalyst 14.12 Omega Driver
  2. 12-Way AMD Catalyst 14.12 vs. NVIDIA 346 Series Linux GPU Comparison
  3. AMD Catalyst 14.12 Omega Driver Brings Mixed Results For Linux Users
  4. 6-Way Winter 2014 Linux Distribution Comparison
Latest Linux News
  1. Linux 3.19 Merge Window Closes Ahead Of Schedule
  2. MIPS R6 Architecture Now Supported By GCC
  3. LowRISC To Feature Tagged Memory & Minion Cores
  4. Intel Skylake Audio Support For Linux 3.19
  5. After 10+ Years, NetworkManager Reaches v1.0
  6. VDPAU Updated To v0.9
  7. An Open Hardware Random Number Generator Proposed
  8. LLVM 3.6 Will Be Branched Next Month
  9. Opera Browser Puts Out Linux Updates For The Holidays
  10. GNOME Shell 3.15.3 Adds Support For High-Contrast Themes
Latest Forum Discussions
  1. The New SuperTuxKart Looks Better, But Can Cause GPU/Driver Problems
  2. XLennart: A Game For Systemd Haters With Nothing Better To Do
  3. Need some hand holding with upgrading xserver
  4. Updated and Optimized Ubuntu Free Graphics Drivers
  5. Debian init discussion in Phoenix Wright format
  6. FPS capped on Linux (AMD fglrx drivers)
  7. Are there an app using HSA ?
  8. Bench specific mount point