On Wed, Apr 01, 2015 at 11:55:11AM +0900, Kamezawa Hiroyuki wrote: > Now, hot-added cpus will have the lowest free cpu id. > > Because of this, in most of systems which has only cpu-hot-add, cpu-ids are > always > contiguous even after cpu hot add. > In enterprise, this would be considered as imcompatibility. > > determining cpuid <-> lapicid at boot will make cpuids sparse. That may > corrupt > exisiting script or configuration/resource management software.
Ugh... so, cpu number allocation on hot-add is part of userland interface that we're locked into? Tying hotplug and id allocation order together usually isn't a good idea. What if the cpu up fails while running the notifiers? The ID is already allocated and the next cpu being brought up will be after a hole anyway. Is this even actually gonna affect userland? -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
