On 06/09/2019 12:09, George Dunlap wrote: > There was a discussion on the community call about the core scheduling > series being developed by Juergen Gross [1]. The conclusion can be > summarized as follows: > > * We normally wait to check in series until they are quite good -- all > the i's dotted and all the t's crossed > > * This is for several reasons; primarily because once code gets checked > in, it rarely gets looked at again. In particular, there's nothing > stopping the submitter from neglecting to do important clean-ups, in > spite of their best intentions; leaving the maintainer or the rest of > the community to do it. > > * However, for particularly long, complicated series like the core > scheduling series, this can have significant downsides. Rebasing a > 60-patch branch regularly is a lot of churn for little value; and core > parts of the series which are mostly complete are currently only getting > sporadic dev testing rather than the wide range of testing they would > get from being in staging. > > * XenServer and SuSE are both long-term community members with a strong > incentive to maintain and improve the feature; so the risk of the > feature being left for the community to maintian is relatively now. > > With all those things in mind, the conclusion was to lower the > "check-in" threshold from what it normally is, in order to allow the > series to be checked in in the near future, in enough time at least for > the "default off" to be well-tested by the 4.13 release. > > The criteria we sketched out were: > > * All the patches still need appropriate Ack / R-b's > > * There should be reason to believe that the series will have little to > no impact on "thread mode" (threads being the unit of scheduling; i.e., > the status quo) > > WRT the second point, apparently XenServer have been testing the series > regularly for some time, and are satisfied from a testing perspective > that there is no significant degradation for the series when in "thread > mode".
To clarify, we've been testing core mode, and providing feedback on the xen-devel threads. We are currently organising an extended regression test to run in thread mode to increase the confidence of the previous bullet point. > So this would really be a recommendation / license to the various > maintainers involved; primarily Dario, I think (since I probably won't > have time to review the series). > > No decisions are official until discussed on xen-devel; so the decision > will not be considered official until a few days have passed without > objection. And of course, if anyone at the meeting had a different > understanding of what was said, or has something to add, please do so. No objection from me at all. ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
