The Past 12 Linux Kernels Benchmarked

After another two months went by, the Linux 2.6.14 kernel was introduced with the numa-aware slab allocator, SELinux memory improvements, FUSE file-system, ipw2100/ipw2200 drivers for Intel Centrino Wireless chipsets, and initial open-source support for the Radeon R300 graphics cards. Coming out just after the New Year in January of 2006 was the Linux 2.6.15 kernel. Changes this time around affected VFS, page table scalability, hot-plug CPU support of new physical processors, NTFS file-system write support, PCI Express support for the R300 commit in the Linux 2.6.14 kernel, and kernel frame-buffer support for NVIDIA's GeForce 7 series.

Warming things up in March of 2006 was the Linux 2.6.16 kernel, which had a horde of changes. Among the many changes in Linux 2.6.16 was support for the Cell processor, configfs file-system, and support for a lot of new hardware. Some of the detailed changes in the Linux 2.6.16 kernel include the introduction of high-resolution timers, SWAP migration, adding the SLOB allocator, Intel ICH8 support, and XFS support with SELinux.

Running off the energy of the Linux 2.6.16 kernel, hitting the web in June of 2006 was the next 2.6.17 kernel. Major highlights for this release included the Broadcom bcm43xx driver, user-space software suspend interface, generic RTC sub-system, and various file-system updates. The Linux 2.6.18 kernel that met the world in September of 2006 featured light-weight user-space priority inheritance, a new power saving policy for multi-core machines, libata improvements (NCQ, hot-plug, warm-plug, boot-plug support), the default CFQ scheduler, and a generic IRQ layer.

The Linux 2.6.19 kernel, which arrived in late November, featured an experimental version of the EXT4 file-system, CPU hot-plug and memory hot-add for x86_64, removal of some OSS audio drivers, and other driver changes. In February of this year, the Linux 2.6.20 kernel introduced support for the Sony PlayStation 3, integration of KVM virtualization, and i386 para-virtualization support were among the many changes.

Continuing in the virtualization fun, the Linux 2.6.21 kernel that was introduced in April featured the VMWare-developed VMI (Virtual Machine Interface), KVM updates, tickless kernel support, and various other core changes.

Coming out just a few weeks after the Linux Foundation Summit was the Linux 2.6.22 kernel. The highlights for this kernel was the new SLUB allocator, a new wireless stack, a new Firewire stack, Blackfin architecture support, and a host of driver and file-system updates.

Finally, onto the Linux 2.6.23 kernel that was released earlier this month. Linux 2.6.23 introduced the much talked about CFS process scheduler, on-demand read-ahead, lguest and Xen virtualization support, stable user-space driver API, and improvements to the XFS and EXT4 file-systems.

Without further ado, the benchmarks used consisted of LAME encoding, Ogg encoding, Gzip compression, Gzip un-compression, network HTTP timed file transfers, ImageMagick JPEG resizing, timed disk reads (hdparm), and RAMspeed. On the following pages are the benchmarks.