Re: svn to git, N-squared?

From: Linus Torvalds <torvalds@osdl.org>
Date: Jun 12, 2006, 16:12 UTC
Message-ID: <Pine.LNX.4.64.0606120906210.5498@g5.osdl.org>
In-Reply-To: <9e4733910606120855p1cec9acfy62dadb89c11756b4@mail.gmail.com>

On Mon, 12 Jun 2006, Jon Smirl wrote:

> 
>  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
> 14525 jonsmirl  16   0  604m 391m 1904 S   24 38.7 916:53.39 git-svnimport
> 20947 jonsmirl  17   0     0    0    0 R    1  0.0   0:00.03 git-svnimport

Hard to tell, it's obviously got short-lived processes there too that it's not showing, but equally obviously that svnimport script itself is spending an alarming amount of CPU time. I don't think it should do that much processing, but since it's written in perl, I can't read it.

Are there any other directories that seem to be growing (eg some temp-file directory where the old files aren't cleaned away?). I can't imagine what else it could be doing in kernel space than simply some silly filesystem operation, but dang it all, Linux filesystems are usually very efficient indeed, unless we're talking huge directories (and if it's not the git object directory any more, it must be something else).

At least with the cvs importer I have _some_ clue what it's doing, since I wrote an earlier version myself (very different, but at least I know what the operations are). SVN has always just confused me, and I have no idea what svnimport does, so I think I'll have to defer to somebody who actually knows the code.

Smurf, have you looked at any larger repositories?

		Linus