[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] 0/4 Xen Scheduling Groups
Scheduling Groups Scheduling groups provide the ability to combine domains into a group assocation. One domain is designated as the group master. The other domains are designated as group members. There may be only one master domain for each group, and one or more member domains. A single domain may be either a group master or group member, and never both at the same time. scheduling groups are visible to Xen as a new sub-operation within the domain control Scheduling op. When xen receives a Scheduling op containing the sched-group sub op, it dispatches to the generic scheduling layer, which then calls the active scheduler with the sub-ob information. The grouping/ungrouping, accounting, and scheduling work is done in the active scheduler, whichever that may be. By delegating the processing of the sched-group sub op to the specific scheduler (as opposed to the generic scheduling layer), scheduling groups are opaque to the rest of Xen and each scheduler is free to implement grouping how it sees fit. This also keeps the bulk of the code changes within a specific scheduler implementation and limits the changes to other areas of Xen. There are several possible implementations of scheduling groups. For example, groups could be used as the foundation for a secondary scheduler, where the first level schedules groups, and the second level schedules domains within groups. A good use case is creating a group in which the domains need to be scheduled in a specific order. For example, a stub domain hosting a device model must run prior the the hvm domain it is servicing. Scheduling groups might also be used for support of real-time guests. All real-time guests could be placed in one group which will scheduled pre-emptively and at a finer granularity than other domains. This patchset is limited to groups sharing the master domain's timeslices in the credit scheduler.The three patches that follow are organized as follows: 1/4: Implements the sched-group sub op within the domctrl scheduling hypercall. 2/4: The credit implementation of scheduling groups. 3/4: Tools update for supporting scheduling groups. 4/4:sched-group C utility program to add and remove domains to and from groups. Mike -- Mike D. Day Virtualization Architect and Sr. Technical Staff Member, IBM LTC Cell: 919 412-3900 ST: mdday@xxxxxxxxxx | AIM: ncmikeday | Yahoo IM: ultra.runner PGP key: http://www.ncultra.org/ncmike/pubkey.asc _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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