Re: Kernel SCM saga..

Matt Johnston
2005-04-08T08:43:22Z

On Thu, Apr 07, 2005 at 09:42:04PM -0700, Linus Torvalds wrote:
>
> 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.

That is indeed correct wrt pathnames. The current head of
monotone is a lot better in this regard (the order of 2-3
minutes for "monotone import" on a 2.6 linux untar). The
basic problem is that in the last release (0.17), a huge
amount of sanity checking code was added to ensure that
inconsistent or generally bad revisions can never be
written/received/transmitted.

The focus is now on speeding that up - there's a _lot_ of
low hanging fruit for us to look at.

Matt