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. Acer B286HK: A 28-inch UHD LED 4K Monitor For As Low As $350
  2. Intel Xeon E5-1680 v3 & E5-2687W v3 Compared To The Core i7 5960X On Linux
  3. Intel 120GB 530 Series SSD Linux Performance
  4. Btrfs/EXT4/XFS/F2FS RAID 0/1/5/6/10 Linux Benchmarks On Four SSDs
Latest Linux Articles
  1. Mesa Git Yields Performance Improvements For Newer AMD GPUs
  2. Apple OS X 10.10 vs. Ubuntu 14.10 Performance
  3. Mesa 10.5-devel Brings Some Intel Haswell HD Graphics Changes Over Mesa 10.3
  4. NVIDIA vs. Nouveau Drivers With Linux 3.18 + Mesa 10.4-devel
Latest Linux News
  1. Wine 1.7.32 Updates Its Mono Engine
  2. Mesa 10.4 Release Candidate 3 Is Here For Weekend Testing
  3. GenodeOS 14.11 Now Supports Intel's Wireless Hardware
  4. Jolla Tablet Could Have Upgrades For MicroSDHC, Split Screen, 3.5G
  5. Intel Has Last Round Of DRM Changes For Linux 3.19, Starts Dropping DRI1/UMS
  6. Fedora 21 Release Candidate 1 Awaits Your Testing
  7. GCC 5 Adds Support For ARM's Cortex-A17
  8. KWayland Server Component Coming For KDE Plasma 5.2
  9. NVIDIA Posts Tegra Gallium3D Patch For K1+ Support
  10. Ubuntu 14.10 MacBook Air Tests With Linux 3.18, Mesa 10.5
Latest Forum Discussions
  1. Aliens vs predator for Linux
  2. Updated and Optimized Ubuntu Free Graphics Drivers
  3. Hurrican SDL Port
  4. Roadmap to Catalyst 14.10 ?
  5. how to configure module phoromatic ?
  6. PulseAudio 6.0 Is Coming & Other Linux Audio Plans For The Future
  7. Debian Developer Resigns From The Systemd Maintainership Team
  8. Cant get working Kaveri APU - A10-7850k