WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

RE: [Xen-devel] Repositories and build system

To: Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>, Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Subject: RE: [Xen-devel] Repositories and build system
From: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>
Date: Wed, 29 Apr 2009 09:38:26 -0700 (PDT)
Cc: Yuji Shimada <shimada-yxb@xxxxxxxxxxxxxxx>, Xen Developers <xen-devel@xxxxxxxxxxxxxxxxxxx>, Keir Fraser <Keir.Fraser@xxxxxxxxxxxxx>, "Zhai, Edwin" <edwin.zhai@xxxxxxxxx>
Delivery-date: Wed, 29 Apr 2009 09:39:26 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <18936.30020.370607.334848@xxxxxxxxxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
A few thoughts:

I fear that the real issue is that knowledge of the
locksteps are hidden in people's brains, or at best
in cryptic comments in some sub-repos.  For any
solution to work, this knowledge needs to be made
available, at least in human-readable format and
preferably (or perhaps additionally) in machine-parseable
format.

The problem is that each developer is working on a
different component and has little interest in the
other components other than to ensure they don't
break "the component I care about".  (And sometimes
a developer cares about two or more components...
and may become the "lockstep culprit".)  Furthermore,
there are sometimes "partial locksteps", where
say, a new qemu is required beyond this changeset
in Xen, but only if you are using stub domains.

Generally, I think the idea of a meta-pull and
meta-make are good (and maybe a meta-install?),
but in order to be useful, they need to work not
only on "latest" but older branches of components
as well.  For example:

"Pull and build all latest known stable components
that work with xen-unstable changeset 19314"

Without the "lockstep database", this is impossible.
And without this functionality, binary searching
for a problem is also impossible.

> -----Original Message-----
> From: Ian Jackson [mailto:Ian.Jackson@xxxxxxxxxxxxx]
> Sent: Wednesday, April 29, 2009 9:42 AM
> To: Stefano Stabellini
> Cc: Yuji Shimada; Xen Developers; Keir Fraser; Zhai, Edwin
> Subject: [Xen-devel] Repositories and build system
> 
> 
> Stefano Stabellini writes ("Re: [Xen-devel] [PATCH] [Xend] 
> Fix HVM PCI hot removal failure"):
> > A two way synchronization between the qemu hg mirror and 
> the qemu git
> > repo would mean trouble.
> > 
> > Maybe we could find a way to mirror the qemu git repo inside the
> > xen-unstable hg repo, but it would still just a mirror.
> 
> I agree that the current situation isn't ideal.  I had hoped that we
> could avoid constantly making changes that introduce cross-repository
> incompatibilities but it seems to be too difficult to do that.  We
> keep introducing new lockstep changes.
> 
> Stefano's idea of mirroring the qemu git repo inside the xen-unstable
> hg repo would be one approach.  It could probably be done, although it
> would be a novel arrangement.
> 
> I think a better thing to try would be to make it easier for people to
> pull and update all of the sub-repos at once.  It's not just qemu - we
> have linux (which is in at least two major branches: 2.6.18 and pvops)
> and now some of the Ocaml work too.  Perhaps it's time to create a
> meta-component which permits `make pull', `make world', etc. ?
> 
> Ian.
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel
>

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel