Larry McVoy, the author of BitKeeper (BK), recently sent an email to the lkml briefly summarizing the past two months of BitKeeper usage for the Linux kernel. He acknowledged that "BitKeeper overhead for maintaining this information, the changeset stuff, is about 7MB uncompressed. It started at about 1.5MB for the initial baseline, so we're growing at about 3MB/month, which is a problem."
He posted a four point list of improvements planned for BK in the near future. The changes include a fix for the problem mentioned above, as well as better performance of updates, LODs for temporary patch inclusion testing, and nested repositories.
" The first goal of this project is to create virtual servers sharing the same machine. A virtual server operate like a normal Linux server. It runs normal services such as telnet, mail servers, web servers, SQL servers. In most cases, the services run using standard configuration: The services are running unaware of the virtual server concept.Normal system administration is performed with ordinary admin tool. Virtual servers have users account and a root account."
One big improvement in this version is the introduction of a simple install script for RedHat 7.2 systems. Author Jacques Gelinas adds, "I would be interested in other script like this to install SuSE, Mandrake and Debian from scratch."
kbuild 2.5 v2.0 was released today by Keith Owens. One major improvement in this new version is a 30% speed increase over kbuild 2.4 by replacing a text-file read at each compile step with a memory mapped database (mdbm from BitKeeper). Regarding the speed gain, Keith says, "Now the nay-sayers will have to find something else to complain about!". He also warns, "... You know what they say about .0 releases ... User beware."
Currently this version is only available for i386 architectures. However, Keith adds, "Patches for other architectures and kernels will be out in the next few days, it takes time to generate and test patches for multiple architectures against different kernel trees."
Another interesting debate recently ensued on the lkml, this time with kernel guru Alan Cox in the middle. The topic was related to the GPL (hence the emotions involved), though specifically referring to the changing of an EXPORT_SYMBOL_GPL flag to EXPORT_SYMBOL. Among the questions raised is whether this infringes upon a developer's rights...
Much of the debate follows, involving many kernel notables, including Andrea Arcangeli, Alan Cox, Rik van Riel, Ingo Molnar, and Linus Torvalds. Many good points are raised on both sides of the issue, making for an interesting read...
Linus recently returned from a two week vacation, announcing the release of "a largish 2.5.8-pre1 patch". Following the announcement, he commented on the earlier April Fool's message. He says, "PS.
A recent thread on the lkml discussed the addition of another scheduler priority. Currently, referring to 'linux/include/schedule.h' in 2.4 (follows), there are three such priorities available. SCHED_FIFO, SCHED_RR and SCHED_OTHER. The additional priority in question is SCHED_IDLE.
This first two, SCHED_FIFO and SCHED_RR, are for real time processing. The former handles processes "first in, first out". Once a SCHED_FIFO process gets the CPU, it keeps it until finished, or until a higher priority process comes along. The latter handles processes "round robin", sharing time slices among all SCHED_RR process of equal priority. The third, SCHED_OTHER, is the standard, aka "time-share processing".
As for the discussed potential SCHED_IDLE, it would schedule a process to run only when the CPU was idle, not busy with other tasks. In the following thread, Robert Love says, "There is just a lot more to SCHED_IDLE than 'make the task only run when nothing else wants to'", explaining that as simple as it sounds, a lot of work is involved in the implementation.
JFS v1.0.17 for Linux was released today. The announcement/changelog follows.
"IBM's journaled file system technology, currently used in IBM enterprise servers, is designed for high-throughput server environments, key to running intranet and other high-performance e-business file servers. IBM is contributing this technology to the Linux open source community with the hope that some or all of it will be useful in bringing the best of journaling capabilities to the Linux operating system."
Par for the course, "shocking" email hit the lkml on April 1'st attributed to Linus Torvalds. This year's email stated, "Linux needs new leadership", putting Linus' succesor up to a vote. A surprising number of people thought the email was real, expressing dismay at Linus' "choice" to abandon Linux. The contrived email follows.
Jeremy Jackson asked "which kernel debugger is 'best'?" on the Linux Kernel Mailing List.
NTFS v2.0.1 has been released, quickly following 2.0.0 (see earlier story). The main reason for this quick follow-up release is to provide a new download link - the old link is evidently no longer valid. Additionally, there has been a minor source code change to set the executable bit on NTFS mounted binaries by default, as "has often been requested by wine users".
The Enterprise Volume Managment System Project has released v1.0.0 of their storage management system. The GPL'd code is developed by IBM, and is compatible with both stable kernel 2.4.17 and development kernel 2.5.3. Find more information on their docs page, and in the latest release notes.
"The Enterprise Volume Management System ( EVMS ) Project has the goal of providing unparalleled flexibility and extensibility in managing storage. It represents a new approach to logical volume management, as the architecture introduces a plug-in model that allows for easy expansion or customization of various levels of volume management."
"We did indeed lose the primary disk (IBM 40GB, I am starting to lose all the respect I had for IBM drives, this is one of many that has failed on me personally). I have restored from the backup disk, and in the process redone hardlinks across all the linux kernel trees, which saved about 5GB (nice). All trees which are now on bkbits.net check clean, which means BK thinks all the files are there and that the checksums are correct, a fairly reasonable indication that we are in good shape."
Find an earlier discussion about BitKeeper here. Larry's full emails follow.