Messages in this thread | | | From | <> | Subject | Re: [PATCH v6 00/21] arch_topology: Updates to add socket support and fix cluster ids | Date | Tue, 5 Jul 2022 20:14:38 +0000 |
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On 05/07/2022 21:07, Sudeep Holla wrote: > On Tue, Jul 05, 2022 at 07:06:17PM +0000, Conor.Dooley@microchip.com wrote: >> [Adding back the CC list from the original thread] >> >> On 05/07/2022 13:27, Brice Goglin wrote: >>> [You don't often get email from brice.goglin@inria.fr. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] >>> >>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >>> >>> Hello Conor >>> >>> I am the main developer of hwloc [1] which is used by many people to >>> detect the topology of servers. We're started to see some users of hwloc >>> on RISC-V and we got some reports about the topology exposed by >>> Linux/sysfs being wrong on some platforms. >>> >>> For instance https://github.com/open-mpi/hwloc/issues/536 says HiFive >>> Unmatched with SiFive Freedom U740 running Linux 5.15 exposes a single >>> core with 4 threads instead of 4 cores, while StarFive VisionFive v1 >>> with JH7100 running 5.18.5 correctly exposes 2 cores. >> >> And with Sudeep's patches applied I get (next-20220704): >> # hwloc-calc -N core all >> 1 >> # hwloc-calc -N pu all >> 4 >> On a PolarFire SoC (so the same as a SiFive U540). >> So unfortunately, these patches are not the fix you seek! >> > > Not sure what you mean by that ?
Nothing meaningful really, just saying that this patchset was unrelated to the problem he reported his response to it.
> >> Wracked my brains for a bit, but could not see any differences >> between the U740 and the JH7100. Culprit seems to be the lack >> of a cpu-map node (which is only present in the downstream dt). >> > > Indeed, the topology depends on /cpu-map node. However on ARM64 we do > have fallback settings in absence of /cpu-map node so that it is handled > correctly. I wasn't sure what was or can be done on RISC-V as /cpu-map > is optional. > >> I've sent patches for the upstream devicetrees: >> https://lore.kernel.org/linux-riscv/20220705190435.1790466-1-mail@conchuod.ie/ >> > > I will take a look. > >>> Does it depend a lot on the platform because >>> device-tree and/or ACPI aren't always properly filled by vendors? > > Absolutely. > >>> Does it depend a lot on the Linux kernel version? > > Ideally not much, but hey we had some issues on Arm64 too which this series > is addressing. > >>> Should I expect significant improvements for both in the next months? > > Not much in topology or nothing planned. I have no idea on NUMA > > > Hi Conor, > > I would have preferred you to add me to the original thread and referred > this thread from there. I don't want to derail the discussion in this > thread as nothing much can be done here.
This is the original thread! It was just one off-list email that was a to me only response to this arch_topologu thread that you can see here
But yeah - should have CCed you on the cpu-map stuff too.
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