Re: [Xen-devel] S3 is broken again in xen-unstable

[Ben Guthro <ben@xxxxxxxxxx>]

On Fri, Apr 26, 2013 at 9:17 AM, Ian Campbell <Ian.Campbell@xxxxxxxxxx> wrote:
> On Fri, 2013-04-26 at 13:19 +0100, Ben Guthro wrote:
>> On Fri, Apr 26, 2013 at 4:10 AM, Ian Campbell <Ian.Campbell@xxxxxxxxxx> 
>> wrote:
>
>> > Some questions:
>> >       * How automatable is s3?
>> >       * In particular can we automate the wakeup? s3 is save to RAM
>> >         IIRC, and most power control in the test system is done with PDU
>> >         power cycling.
>>
>> I spoke with George Dunlap  a bit about this while I was over in the
>> UK a few weeks ago, and drew up an example shell script for this:
>> http://xen.markmail.org/thread/ghj2ffngemccq6p4
>> Marek also weighed in, and included some of his own tests, and experiences.
>>
>> In my experience, this mechanism is about as reliable as your RTC. On
>> some systems you might tell it to sleep for 30s, and it will wake in
>> 10s.
>>
>> That said, when things go wrong, the machine does need to be power
>> cycled...so if you are not physically located near the machine under
>> test, you would need a PDU as a recovery mechanism, I suppose.
>
> That'#s OK, all the systems in the test harness would have to have PDU
> for the other test cases (initial install etc) anyway.
>
>> >> Would it be helpful to maintain a branch in my xenbits repo that could
>> >> be a rebased version of konrad's acpi-s3 patches against Linus' latest
>> >> kernel?
>> >
>> > What is keeping those out of Linus' tree?
>>
>> Added Konrad here, but I believe he is on vacation this week.
>> This has been a bullet point on his OSS presentation, as outstanding
>> pvops work for at least 3 years now.
>>
>> IIRC, the x86 guys NACK'ed the change as being too invasive.
>> I googled around a bit, but can't seem to find the thread about it.
>
> I wonder if it might be something like that :-/

FWIW, I believe we are over another hurdle here.
I have commitment from the acpi maintainer (Rafael Wysocki) that the
following patches will be included in the linux-3.11 merge window:

https://lkml.org/lkml/2013/5/14/465

When this is accepted, this should give "out of the box" S3
functionality with Xen

Once Xen-4.3 is released, I would like to revisit trying to see if
there would be some way to get something into the automated test
system.


Ben


>
>> > Once we have a test case in the standard flights then we can consider
>> > the options around new flights testing other trees.
>>
>> I'm not sure I understand this point.
>> Are you saying you want to see a test that fails in the standard test
>> flight first...because without Konrad's patches, it will be guaranteed
>> not to work.
>
> Right. AIUI the flights (and I may be using the wrong term here) are
> somewhat uniform and and few in number and get run with various
> combinations inputs (Xen tree, Linux tree, Qemu tree), so there is
> effectively one "test Linux PV kernel flight" and one "test Xen PV
> guests flight" etc, so we want to get S3 into those flights, with the
> existing set of "* tree" inputs.
>
> IOW we should add a new row to the grid
> http://www.chiark.greenend.org.uk/~xensrcts/logs/17816/ for s3 testing
> and then we can consider adding a new column with a different set of
> tree's as input.
>
> Ian J may have a different opinion on how to approach, but he's away
> until mid next week.
>
>> ...and without other changesets queued up for the 3.10 merge window,
>> non-boot CPUs will always have incorrect C-states.
>
> It's OK to add the tests before things work.
>
> Ian.
>
>

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel