From: Linus Torvalds osdl.org>
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Date: 2005-04-08 04:42:04 GMT (1 week, 4 days, 3 hours and 12 minutes ago)
From: Linus Torvalds osdl.org>Subject: Re: Kernel SCM saga.. Newsgroups: gmane.linux.kernel Date: 2005-04-08 04:42:04 GMT (1 week, 4 days, 3 hours and 12 minutes ago) On Thu, 7 Apr 2005, Chris Wedgwood wrote: > > I'm playing with monotone right now. Superficially it looks like it > has tons of gee-whiz neato stuff... however, it's *agonizingly* slow. > I mean glacial. A heavily sedated sloth with no legs is probably > faster. Yes. The silly thing is, at least in my local tests it doesn't actually seem to be _ doing _ anything while it's slow (there are no system calls except for a few memory allocations and de-allocations). It seems to have some exponential function on the number of pathnames involved etc. I'm hoping they can fix it, though. The basic notions do not sound wrong. In the meantime (and because monotone really _ is _ that slow), here's a quick challenge for you, and any crazy hacker out there: if you want to play with something _ really _ nasty (but also very _ very _ fast), take a look at kernel.org:/pub/linux/kernel/people/torvalds/. First one to send me the changelog tree of sparse-git (and a tool to commit and push/pull further changes) gets a gold star, and an honorable mention. I've put a hell of a lot of clues in there (*). I've worked on it (and little else) for the last two days. Time for somebody else to tell me I'm crazy. Linus (*) It should be easier than it sounds. The database is designed so that you can do the equivalent of a nonmerging (ie pure superset) push/pull with just plain rsync, so replication really should be that easy (if somewhat bandwidth-intensive due to the whole-file format). Never mind merging. It's not an SCM, it's a distribution and archival mechanism. I bet you could make a reasonable SCM on top of it, though. Another way of looking at it is to say that it's really a content- addressable filesystem, used to track directory trees.
In the wake of Bitmover CEO Larry McVoy's decision to end the free distribution of the Linux version of the source code management system Bitkeeper, Linux founder Linus Torvalds has written a program called "git" to access the Linux source code repositories, Torvalds wrote in a post to the Linux kernel mailing list. The program, resting at version 0.04 as of April 13, is, according to  Torvalds's README file: ''"a stupid (but extremely fast) directory content manager. It doesn't do a whole lot, but what it _does_ do is track directory contents efficiently."''

When Bitmover changed its licensing scheme, Torvalds wrote that he was looking into using Monotone; he added that he did not want to use Subversion (SVN). According to Kerneltrap.org, on April 7, Torvalds noted, "I detest the centralized SCM model, but if push comes to shove, and we just _can't_ get a reasonable parallell merge thing going in the short timeframe (ie month or two), I'll use something like SVN on a trusted site with just a few committers . . ."

While Torvalds characterized Monotone as slow, he was hopeful that it could be sped up. He anticipated using the pre-Bitkeeper system of "people email patches to Linus" until the 2.6.12 kernel is released in the next month or so.