On Wed, Jun 06, 2018 at 09:53:39AM -0500, Jeremy Linton wrote: > On 06/06/2018 09:44 AM, Morten Rasmussen wrote: > >On Tue, Jun 05, 2018 at 02:08:37PM -0500, Jeremy Linton wrote: > >>The numa mask subset check has problems if !CONFIG_NUMA, over hotplug > >>operations or during early boot. Lets disable the NUMA siblings checks > >>for the time being, as NUMA in socket machines have LLC's that will > >>assure that the scheduler topology isn't "borken". > > > >Could we add an explanation why the numa node mask check is needed in > >the first place. > > >IIUC, we have the check in case the LLC is shared across numa nodes as > >this would cause core_siblings > cpumask_of_node() which breaks the > >scheduler topology. > > Yes, that sounds like a good idea, my comments probably assume that the > reader has been part of these conversations. > > > > >While sharing LLC across numa nodes seems quite unusual, I think it is > >allowed by ACPI. Those systems might already be broken before, so might > >not change anything. It is just worth noting why the check should be > >added back later. > > Right, there isn't anything in ACPI that dictates a system topology > restriction like this. Given that other architectures have built machines > with large directory caches that span numa nodes the check was a safety > measure. Agreed, it seems that another architecture has recently merged support for that: 1340ccfa9a9a -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
