On 30.09.2022 03:40, Wei Chen wrote: >> -----Original Message----- >> From: Jan Beulich <jbeul...@suse.com> >> Sent: 2022年9月29日 20:21 >> >> On 29.09.2022 10:21, Wei Chen wrote: >>> On 2022/9/27 23:48, Jan Beulich wrote: >>>> On 20.09.2022 11:12, Wei Chen wrote: >>>>> --- a/xen/drivers/acpi/Kconfig >>>>> +++ b/xen/drivers/acpi/Kconfig >>>>> @@ -7,4 +7,5 @@ config ACPI_LEGACY_TABLES_LOOKUP >>>>> >>>>> config ACPI_NUMA >>>>> bool >>>>> + select HAS_NUMA_NODE_FWID >>>>> select NUMA >>>> >>>> While I might guess that you've chosen the insertion point to have >>>> things sorted alphabetically, I think here it would be more natural >>>> to select the wider option first and then also select the more >>>> narrow one. >>>> >>> >>> Ok, I will adjust the order. >>> >>>> One further question though: How is this going to work for Arm64 >>>> once it wants to support both the form of NUMA you're working to >>>> enable _and_ ACPI-based NUMA? There better wouldn't be a requirement >>>> to pick one of the two at build time - it would be nice for support >>>> of both forms to be able to co-exist in a single binary. >>> >>> We are also working in this way. In part#3, we will check ACPI first, >>> only when ACPI is off, the DT NUMA will be used by Arm. If ACPI is on, >>> we will skip DT NUMA. >> >> Even more so an answer to my question would be nice: You'll then have >> CONFIG_HAS_NUMA_NODE_FWID=y even on Arm (using PXM as mandated by ACPI >> when in ACPI mode). But then what's the FWID for DT? I know it was me >> to suggest this build time distinction, but I'm afraid I wasn't doing >> much good with that (and I'm sorry). > > How about introducing a flag for selected NUMA implementation to > set it in runtime? > For example: > bool numa_has_fw_nodeid; > > ACPI NUMA will set this flag to 1, but 0 for DT NUMA.
That's an option alongside going back to what you had in an earlier version. Another would be (name subject to improvement) const char *__ro_after_init numa_fw_nid_name; which for ACPI would be set to "PXM" (eliminating the need to pass it to certain functions, albeit the fw_nid will continue to need to be passed anyway). I guess I'm not really certain which of this and your earlier approach I prefer; the boolean you suggest above looks less desirable to me, though. Jan
