Re: Kernel source tree splitting

[Willy TARREAU <willy@w.ods.org>]

On Thu, May 01, 2003 at 07:35:48AM -0700, Martin J. Bligh wrote:
> >> Indeed. But whilst you're waiting, hardlink everything together, and 
> >> patch the differences (patch knows how to break hardlinks). Make a 
> >> script that cp -lR's the tree to another copy (normally takes < 1s), and
> >> then remove the other arches. grep that.
> > 
> > I agree with Martin here, I always use hardlinks, and when I have too many
> > kernel trees, I even recompact them by diff/rm/cp -l/patch to get as small
> > differences as possible. You can have tens of kernels in less than 400 MB,
> > and tools such as diff and grep are really fast because it's easy to keep
> > several kernels in the cache.
> > 
> > The only danger is to modify several files at once with stupid operations
> > such as "cat $file.help >> Documentation/Configure.help" which are
> > sometimes included in some scripts. It would be cool to be able to lock
> > the source, but I never found how (perhaps I should try chattr+i ?). And
> > I don't know how to force vi and emacs to unlink before saving, so I have
> > to be careful before certain operations. But all in all, it's extremely
> > useful.
> 
> find -type f | xargs chmod ugo-w 

that's also what I do when I don't trust a script ;-)

> whenever you make a new copy seems to work pretty well to me. 
> Then you use "dupvi" to edit the files, which is just a little wrapper that
> breaks the link, and edits the file. 

I didn't know about dupvi. But I admit that it's really easy to break the link
before starting vi, to ensure there's no problem.

> For added paranoia, I suppose you could make your "main" views (eg the
> unpatched ones) owned by another user.

this could help emacs because it tries every possibility to save a file, even
changing its rights if there's no other way.

> But I've never had a problem with just chmod, and I have a lot of views ...
> 1689 all linked together ;-)
> 
> -r--r--r--  1689 fletch   fletch      18691 Nov 17 20:29 COPYING

and I thought it was dirty when I began to reach 50 links.... :-)

Cheers,
Willy