February 20, 2019

Linux 2.6.37 Kernel Promises to Unlock OS

First Linux Kernel of 2011 Arrives

  • January 5, 2011
  • By Sean Michael Kerner

Linus Torvalds is starting 2011 off with a bang with the release of the 2.6.37 Linux kernel. The new kernel is the first release since 2.6.36 debuted in October.

The goal of the new 2.6.37 kernel is to provide developers with improved Linux performance, security and scalability.

From a performance perspective the 2.6.37 kernel removes the Big Kernel Lock (BKL). The BKL is a legacy part of the Linux kernel that has now been fully supplanted by more modern and efficient locking mechanisms for kernel processes.

Memory management also gets a boost with a new retry page fault when blocking on disk transfer patch, which was authored by Google developer Michel Lespinasse. According to Lespinasse, with the patch, a read access that used to perform at 55 iterations per second will now perform at 15,000 iterations per second, with the patch installed.

Lespinasse isn't the only one that sees promise in the new patch.

"This looks like a nice improvement for some multi-threaded programs, specifically those where many threads perform mmap or other operations related to memory layout and heavy concurrent I/O takes place through such memory areas." Novell Linux kernel developer Michal Hocko told InternetNews.com.

The actual impact that the new memory management patch will have on real-world workloads remains to be seen, Gerald Pfeifer, director product management, SUSE Linux Enterprise told InternetNews.com.

"It is generally hard to predict how such changes are going to affect real-life workloads, so we closely work with customers and ISVs to tune both their applications and SUSE Linux Enterprise for optimum performance," Pfeifer said. "In the course of that, we also backport changes from the mainline kernel, and we develop new changes and submit those upstream."

Linux performance is also set to get a boost with improved I/O throttling support including in the 2.6.37 kernel. The improved I/O throttling includes group support for READ and WRITE bytes per second throttling rules.

Improvements have also been made to the EXT4 and Btrfs filesystems that enhance scalability and performance. EXT4 is now often used by Linux distribution as the default Linux filesystem and in 2.6.37, SMP scalability is improved. In contrast, Btrfs is a next generation Linux filesystem effort that is led by Oracle and is still in the process of maturation.

Security gets a usability boost in 2.6.37 with a number of updates to SELinux (Security Enhanced Linux). One of the new SELinux features is a fast status update interface that was authored by NEC.

Red Hat developer Eric Paris authored a separate SELinux patch that will allow userspace to read policy back out of the Linux kernel.

"There is interest in being able to see what the actual policy is that was loaded into the kernel," the Linux commit file for the patch states. "The patch creates a new selinuxfs file /selinux/policy that can be read by userspace. The actual policy that is loaded into the kernel will be written back out to userspace."

There is also some new IPv6 support in the 2.6.37 kernel as well. Linux 2.6.37 adds support for IPv tunnel mode, as well as something known as 'Any-IP' support.

"AnyIP is the capability to receive packets and establish incoming connections on IPs we have not explicitly configured on the machine," the kernel commit file states.

Sean Michael Kerner is a senior editor at InternetNews.com, the news service of Internet.com, the network for technology professionals.

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