See also: last week's Kernel page.

Kernel development

2.3.99-pre6 turned up some problems with memory management that cause poor performance under some types of loads. Memory management hacker Rik van Riel has put out a patch to fix some of the problems; pre7 should presumably work better.

The current stable kernel release is still 2.2.14. Alan Cox tells us that the current 2.2.15pre20 patch, with a "one-line change" will be the real release, once Linus recovers from moving to a new house and has the cats and children settled down. It may well be out by the time you read this.

Update: 2.2.15 was released just as LWN went to "press." As soon as release notes become available, we'll post a note on the LWN daily updates page.

2.0.39pre4 has been released by David Weinehall. No word on when the real update for this ancient kernel will come out.

Resizing of ext2 filesystems is now available with free code. Way back in May, 1998 Ted Ts'o announced that he had written an ext2 resize utility under contract with PowerQuest. After a period of time, resize2fs was to cease being proprietary software and would be released under the GPL. That period of time has finally passed. The ext2 resizer will be part of e2fsprogs 1.19, which will be released "real soon now." A beta version can be found via the e2fsprogs web site on SourceForge; back up your disk first, though...

Automatic mounting of devfs remains a topic of discussion, after Richard Gooch put out a don't blame memessage regarding the change, which was inserted last week by Jeff Garzik. The final solution looks to be the addition of yet another configuration option which controls whether devfs is mounted automatically at boot.

Mr. Gooch has been busy in general, having released devfs v165, v166 and v167, along with devfsd 1.3.6, 1.3.7, and 1.3.8.

What's in your kernel? The Linux kernel is typically presented as the constant, unifying component that is the same in all distributions. Many distributors, however, ship heavily modified kernels with their products. As the first installment of an irregular series, LWN took a look at the Linux-Mandrake 7.0 kernel to see what they did to it. Here's what we found:

• The base kernel in this distribution is 2.2.14. Interestingly, the source package actually contains 2.2.13, with the 2.2.14 patch being applied at build time.

• A number of disk- and filesystem-oriented patches have been applied, including support for multi-session CD's, a large IDE patch from Andre Hedrick, a patch tightening directory permissions, and Supermount, of course. The kernel source package also includes the ext2 compression patch, but it is not actually installed into the kernel that gets built.

• The lm_sensors hardware monitoring patch has been added. There is also an updated eepro100 ethernet driver, the raw I/O patch, a PCI bus patch, the IP virtual server patch, the RAID patch, a patch raising the maximum number of processes to 2560, a Pentium III support patch, the big memory patch set, and some scheduling tweaks.

• The ALSA 0.4i sound drivers have been added in, as has the emu10k (SB Live) driver.

• The Mandrake kernel also includes the binary-only PCTel winmodem driver.

• Some "Solar Designer" security patches, such as a non-executable stack, are included but are only applied when building a "secure" kernel. The secure kernel is used when one of the higher security levels is selected at installation time.

A number of little adjustments are there as well, for a total of 41 different patches. Plus, of course, they put in the Mandrake boot logo. A number of the patches are credited to either Red Hat or SuSE.

Overall it's a pretty straightforward kernel, with a lot of little fixes and a few additional features (RAID, Supermount, ALSA, big memory...) added.

Other patches and updates released this week include:

• Jeff Garzik has announced a preliminary release of his "kernel compatibility layer," designed to ease the backporting of 2.3.x drivers to older kernels.

• ReiserFS 3.6.5 beta has been released. The ReiserFS folks are steadily working through their issues; it still doesn't work, however, with NFS.

• A new version of the Netfilter HOWTO suite has been released by Paul Rusty Russell.

• Version 0.7 of aboot, the secondary bootloader for Alpha systems, has been released by David Huggins-Daines.

Section Editor: Jonathan Corbet

For other kernel news, see: Kernel traffic Kernel Newsflash Kernel Trap Linux 2.5.x Porting help

Other resources: Kernel Source Reference L-K mailing list FAQ Linux-MM Linux Scalability Effort Kernel Newbies Linux Device Drivers

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