Re: Change set based shallow clone

["Jon Smirl" <jonsmirl@gmail.com>]

On 9/10/06, Linus Torvalds <torvalds@osdl.org> wrote:
> On Sun, 10 Sep 2006, linux@horizon.com wrote:
> >
> > A direct fork() (or even faster, vfork) and exec() is going to have a
> > lot less overhead, although it's more work to code.  See Stevens for
> > excellent examples.
>
> Well, that said, the Linux fork/exec/exit is certainly fairly efficient,
> but nothing can hide the fact that it _is_ a very expensive operation.

cvs2svn + fastimport can import the same Mozilla repo in about 2hrs
that was taking parsecvs about five days to do. The algorithms are not
that different, cvs2svn is probably slower than parsecvs for detecting
changesets. The difference is mostly due to the removal of forks.

Is the kernel mapped into user processes using huge pages? That would
reduce some of the pressure on TLBs. Another thing that should be
mapped with huge pages is the video RAM.

-- 
Jon Smirl
jonsmirl@gmail.com