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. 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 GLAMOR Benchmarks With X.Org Server 1.16
  2. RadeonSI Gallium3D vs. Catalyst At 4K UHD On Linux
  3. MSAA RadeonSI Gallium3D Performance Preview
  4. Intel Core i7 5960X CPU Core Scaling Under Linux
Latest Linux News
  1. SNA & UXA Intel Benchmarks With X.Org Server 1.16
  2. Graphics Driver Changes Coming In The Linux 3.18 Kernel
  3. Tropico 5 Being Released For Linux Gamers This Week
  4. Eclipse IDE Starts Firing Up On Wayland's Weston
  5. OpenSUSE Announcement On SUSE's Recent Merger
  6. Valve Begins Publicly Tracking AMD Catalyst Linux Issues
  7. Digia Qt Spinoff Is Called "The Qt Company"
  8. GNOME 3.14 Makes More Progress In Running Natively On Wayland
  9. Minix 3.3 Released With Cortex-A8 ARM Support, NetBSD Userland Compatibility
  10. More Intel DRM Changes Queued For Linux 3.18, Including Old i830M Fixes
Latest Forum Discussions
  1. Stop grabbing my keyboard :(
  2. New Group Calls For Boycotting Systemd
  3. Best Radeon for a Power Mac G5?
  4. Updated and Optimized Ubuntu Free Graphics Drivers
  5. New stress testing utility for GPU's
  6. Hd 6850
  7. support for first generation UVD blocks (RV6xx, RS780, RS880 and RV790)
  8. Nvidia joins the ranks of Apple and Microsoft