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Linux Kernel 2.6.11 Supports InfiniBand

The Linux world is bracing for the final release of the new Linux 2.6.11 kernel, which will include a long list of driver updates and patches, with InfiniBand support perhaps being one of most interesting new additions.

Late last night, Linux creator Linus Torvalds issued the fifth release candidate for the 2.6.11 kernel. The first 2.6.11 RC was issued on Jan. 12; the second on Jan 21; the third on Feb. 2; and the fourth on Feb. 12.

In the RC5 posting, Torvalds indicated that it was likely the last RC before the final release.

"Hey, I hoped -- rc4 was the last one, but we had some laptop resource conflicts, various ppc TLB flush issues, some possible stack overflows in networking and a number of other details warranting a quick -- rc5 before the final 2.6.11," Torvalds wrote.

"This time it's really supposed to be a quickie, so people who can, please check it out, and we'll make the real 2.6.11 asap."

The long list of updates in the 2.6.11 kernel includes architecture updates for x86-64, ia64, ppc, arm and mips, as well as updates to ACPI , DRI (Direct Rendering Infrastructure, which permits direct access to graphics hardware for X Window System users), ALSA (Advanced Linux Sound Architecture, which provides MIDI and audio functionality to the Linux), SCSI and the XFS high-performance journaling filesystem.

The 2.6.11 kernel will also be significant in that it includes driver support for the InfiniBand interconnect architecture. InfiniBand, which is derived from its underlying concept of "infinite bandwidth," is a switched fabric interconnect technology for high-performance network devices that is common in a number of supercomputer clusters.

The upcoming inclusion of InfiniBand support in the Linux kernel is a major step according to the InfiniBand Trade Association.

"The inclusion of InfiniBand drivers in the upstream Linux kernel is a significant milestone," Ross Schibler, CTO of InfiniBand vendor Topspin Communications, told internetnews.com.

InfiniBand support was available previously in various Linux distributions, but it wasn't part of the mainstream kernel.org Linux.

"This now means that anyone that downloads a kernel will have automatic access to the software," explained Schibler. "It also means that any upcoming distributions (Red Hat, SUSE, etc.) will have the software included on their CDs. Previously SUSE had it on a distribution, but only in the 'unsupported' directory."

Schibler sees the inclusion of InfiniBand as a testament to the maturation of the technology.

"Now that the technology has matured to such a point that Linus has accepted it into the kernel, the way is paved for greater distribution of the code and accelerated deployment of the technology," Schibler said.

The previous Linux kernel.org release, version 2.6.10 was issued on Dec. 24 after two release candidates. Linux distribution began including the 2.6.10 thereafter with Red Hat's Fedora Project being one of the first.

Fedora Core 3 initially shipped with the 2.6.9 kernel and then upgraded to the 2.6.10 kernel on Jan 13. Mandrakelinux's 10.2 Beta 3 also includes the 2.6.10 release. SUSE Linux 9.2 currently includes the 2.6.8 kernel.

Including the most recent kernel into a distribution is not a particularly easy task. The upcoming Debian, code-named Sarge, will only ship with the 2.6.8 kernel. In a release update e-mail, Debian Sarge release manager Andreas Barth related that a meeting was recently held to review the status of which kernel they would include.

"The team leads involved eventually decided to stay with kernel 2.6.8 and 2.4.27, rather than bumping the 2.6 kernel to 2.6.10," Barth wrote. "This decision was made upon review of the known bugs in each of the 2.6 kernel versions; despite some significant bugs in the Debian 2.6.8 kernel tree, these bugs were weighed against the additional delays that a kernel version bump would introduce in the schedule for debian-installer RC3."

"As it happens, preparing 2.4 and 2.6 kernels with the security fixes for all architectures took roughly two months from start to finish, during which time preparation of the next debian-installer release candidate has been entirely stalled," he added.