Hi Thomas, On 7/10/19 12:58 PM, Thomas Gleixner wrote: > Hoan, > > On Wed, 10 Jul 2019, Hoan Tran OS wrote: >> On 6/25/19 3:45 PM, Thomas Gleixner wrote: >>> On Tue, 25 Jun 2019, Hoan Tran OS wrote: >>>> @@ -1567,15 +1567,6 @@ config X86_64_ACPI_NUMA >>>> ---help--- >>>> Enable ACPI SRAT based node topology detection. >>>> >>>> -# Some NUMA nodes have memory ranges that span >>>> -# other nodes. Even though a pfn is valid and >>>> -# between a node's start and end pfns, it may not >>>> -# reside on that node. See memmap_init_zone() >>>> -# for details. >>>> -config NODES_SPAN_OTHER_NODES >>>> - def_bool y >>>> - depends on X86_64_ACPI_NUMA >>> >>> the changelog does not mention that this lifts the dependency on >>> X86_64_ACPI_NUMA and therefore enables that functionality for anything >>> which has NUMA enabled including 32bit. >>> >> >> I think this config is used for a NUMA layout which NUMA nodes addresses >> are spanned to other nodes. I think 32bit NUMA also have the same issue >> with that layout. Please correct me if I'm wrong. > > I'm not saying you're wrong, but it's your duty to provide the analysis why > this is correct for everything which has NUMA enabled. > >>> The core mm change gives no helpful information either. You just copied the >>> above comment text from some random Kconfig. >> >> Yes, as it's a correct comment and is used at multiple places. > > Well it maybe correct in terms of explaining what this is about, it still > does not explain why this is needed by default on everything which has NUMA > enabled. Let me send another patch with the detail explanation. Thanks Hoan > > Thanks, > > tglx >