Re: Request a freeze exception for COLO in v4.6

[Ian Campbell <ian.campbell@citrix.com>]

On Mon, 2015-07-20 at 15:27 +0800, Yang Hongyang wrote:
> 
> On 07/17/2015 06:18 PM, Ian Jackson wrote:
> > Wei Liu writes ("Re: [Xen-devel] Request a freeze exception for 
> > COLO in v4.6"):
> > > Ian and Ian, anything to add? What are your opinions?
> > 
> > I think COLO is an exciting and important feature.
> > 
> > Unfortunately I agree with Wei that at this stage taking both 
> > series
> > as they currently stand into 4.6 is not tenable.  (Perhaps if I had
> > been able to help earlier in the release cycle this would have been
> > different; so for that I'm sorry.)
> > 
> > 
> > I would like to see at least the early parts of `COLOPre' in 
> > staging
> > as soon as possible.  There is much preparatory work there which 
> > would
> > be annoying to rebase around, and which has collateral benefits.
> 
> Thanks, if you are going to merge some of the patches, there is the
> latest version of `COLOPre' patchset:
> https://github.com/macrosheep/xen/tree/colo-v9
> The latest 26 commits.

> I think all patches are ready to be merged except:

I would have taken this to mean "are acked", but in fact a reasonable
number of these aren't, although you have addressed the comments from
last time.

I acked these on the basis of what was in the branch:
    libxl/remus: introduce libxl__remus_setup
    tools/libxl: Update libxl_domain_unpause() to support qemu-xen
        (this one was acked-by Wei with my suggestion, which you've
        done so I added it)

but many of the rest have changes which are significant enough to
require reposting IMHO, because I don't feel comfortable acking them
while cherry-picking. (as it happens many wouldn't apply without 7
anyway

> 7  libxl/remus: init checkpoint_callback in Remus checkpoint callback

Unfortunately this had severe knock on effects, i.e. patch 8 onwards
didn't cleanly apply.

I did manage to pick up:
15 tools/libxl: check QEMU state before resume dm

I'm afraid that between the need to repost a bunch of this and the lack
of #7 I only managed to get these 8 to apply:

8db1a08 tools/libxl: Update libxl_domain_unpause() to support qemu-xen
4301269 tools/libxl: check QEMU state before resume dm
c3e886a libxl/remus: introduce libxl__remus_teardown
c230261 libxl/remus: introduce libxl__remus_setup
8dd129f tools/libxl: rename remus checkpoint callbacks
bc3e7ff tools/libxl: move domain resume code into libxl_dom_suspend.c
f1fe54e tools/libxl: move domain suspend code into libxl_dom_suspend.c
73db059 tools/libxl: rename libxl__domain_suspend to libxl__domain_save

Sorting out #7 and reposting would probably unblock a pretty big chunk
of the rest, I think.

Ian.