On 10/01/2018 04:40 PM, Andrew Cooper wrote: > On 01/10/18 16:35, Wei Liu wrote: >> On Mon, Oct 01, 2018 at 04:19:07PM +0100, George Dunlap wrote: >>> On 10/01/2018 04:17 PM, Wei Liu wrote: >>>> On Mon, Oct 01, 2018 at 09:10:25AM -0600, Jan Beulich wrote: >>>>>>>> On 01.10.18 at 16:33, <wei.l...@citrix.com> wrote: >>>>>> On Mon, Oct 01, 2018 at 03:04:02AM -0600, Jan Beulich wrote: >>>>>>>>>> On 30.09.18 at 23:59, <osstest-ad...@xenproject.org> wrote: >>>>>>>> flight 128240 xen-unstable real [real] >>>>>>>> http://logs.test-lab.xenproject.org/osstest/logs/128240/ >>>>>>>> >>>>>>>> Regressions :-( >>>>>>>> >>>>>>>> Tests which did not succeed and are blocking, >>>>>>>> including tests which could not be run: >>>>>>>> test-amd64-amd64-migrupgrade 22 guest-migrate/src_host/dst_host fail >>>>>>>> REGR. vs. >>>>>> 128084 >>>>>>> At the first glance >>>>>>> >>>>>>> libxl: error: libxl_sched.c:232:sched_credit_domain_set: Domain >>>>>>> 1:Getting >>>>>> domain sched credit: Invalid argument >>>>>>> libxl: error: libxl_create.c:1275:domcreate_rebuild_done: Domain >>>>>>> 1:cannot >>>>>> (re-)build domain: -3 >>>>>>> might indicate a problem resulting from the switch to credit2 as the >>>>>>> default >>>>>>> scheduler. But "first glance" here really means what it says - I didn't >>>>>>> look >>>>>>> (yet) at what exactly libxl tries to do there, in the hope that others >>>>>>> may >>>>>>> know without much digging. >>>>>> I think this is due to toolstack trying to set the same scheduler >>>>>> parameters for the newly created guest. >>>>>> >>>>>> But in this test, the destination host is using a different scheduler >>>>>> from the source host. Asking for credit scheduler on a credit2 host is >>>>>> wrong. >>>>>> >>>>>> The relevant snippet in guest cfg (JSON) is: >>>>>> >>>>>> "sched_params": { >>>>>> "sched": "credit", >>>>>> "weight": 256, >>>>>> "cap": 0 >>>>>> }, >>>>>> >>>>>> I can't think of a method to fix it off the top of my head though. >>>>> So is this something that was specified in the original config? Or >>>>> is it just the current value which gets read and an attempt made >>>>> to re-install. If there was no explicit setting in the guest config, >>>>> shouldn't such a "default" setting be retained by not transferring >>>>> any scheduler specifics during migration? >>>>> >>>> No setting in guest cfg. Those values are extracted from the hypervisor. >>>> I think we may be able to not send default values to the remote end. >>> Wait, the migration code reads the scheduler parameters -- even if these >>> have not been explicitly set by the admin -- and sends them along with >>> the migration stream? And if the remote scheduler is different, the >>> migration fails? >>> >>> That's not so good. :-) >> But one can argue that the guest is specific configured that way so it's >> parameters should be preserved. We normally analyse things on a case by >> case basis. > > If there isn't an obvious fix, then the switch of default scheduler > needs reverting until there is a fix present. This is currently > blocking master.
Agreed. I'd argue for ignoring failures to set scheduler parameters on migrate, on the grounds that this will be less risk to the project as a whole than reverting credit2 again. But either way we should do something quickly. -George _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
