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

LTO Support Coming To Linux 3.15, Making For A Faster Kernel

Linux Kernel

Published on 07 April 2014 04:49 PM EDT
Written by Michael Larabel in Linux Kernel
13 Comments

As a potentially significant performance win for the Linux kernel, when compiling the Linux kernel support for link-time optimizations (LTO) are now supported.

Earlier in April I wrote about link-time optimization support for the kernel nearing reality. LTO support for the Linux kernel has been in the works since 2012 but only with Linux 3.15 will it become a mainline possibility. Link-Time Optimizations via GCC and other compilers allow for various compile-time optimizations to be applied across the binary as a whole. Enabling link-time optimizations can yield some significant performance improvements but results in much slower compile times and with large programs can cause problems due to the size of optimizing the complete binary at once.

As explained in the earlier article, the work back in 2012 by Intel developers showed the kernel compile time increased by two to four times and needed 4~9GB of memory to complete the task. However, it was found the resulting Linux kernel image was faster in various benchmarks.

Sent in today by Michal Marek was LTO Kbuild support for Linux 3.15. "It is a separate branch, because it depends on other patches by Andi which were merged through other trees. The link-time-optimization build is an experimental feature, so there one kconfig option to enable it and another kconfig option to disable it (behind a door with a sign 'Beware of the Leopard'...), so that it is not enabled by allmodconfig/allyesconfig."

So it's still a very experimental feature, but it will land for the Linux 3.15 kernel. There's been no recent benchmark results shared of Linux 3.15 with LTO support, but as soon as the release candidates start coming out, we'll proceed to benchmark it at Phoronix. Generating a link-time optimized kernel also requires a new version of binutils and with the GCC 4.9 compiler are many LTO improvements. Stay tuned for benchmarks!

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. openSUSE Factory & Tumbleweed Are Merging
  2. More Fedora Delays: Fedora 21 Beta Slips
  3. Mono Brings C# To The Unreal Engine 4
  4. Coreboot Now Has Support For Intel Broadwell Hardware
  5. Enlightenment's EFL 1.12 Alpha Has Evas GL-DRM Engine, OpenGL ES 1.1 Support
  6. GTK+ Lands Experimental Backend For Mir Display Server
  7. Ubuntu 14.10 Officially Released
  8. Mesa 10.4 Might Re-Enable HyperZ For R600g/RadeonSI
  9. Intel GVT-g GPU Virtualization Moves Closer
  10. GTK+ 3.16 To Bring Several New Features
Latest Forum Discussions
  1. Updated and Optimized Ubuntu Free Graphics Drivers
  2. Ubuntu 16.04 Might Be The Distribution's Last 32-Bit Release
  3. Linux hacker compares Solaris kernel code:
  4. HOPE: The Ease Of Python With The Speed Of C++
  5. Advertisements On Phoronix
  6. Users/Developers Threatening Fork Of Debian GNU/Linux
  7. AMD Releases UVD Video Decode Support For R600 GPUs
  8. Proof that strlcpy is un-needed