Messages in this thread | | | Subject | Re: [PATCH v3] driver core: platform: expose numa_node to users in sysfs | From | John Garry <> | Date | Mon, 22 Jun 2020 11:48:44 +0100 |
| |
On 19/06/2020 04:00, Barry Song wrote: > Some platform devices like ARM SMMU are memory-mapped and populated by ACPI/IORT. > In this case, NUMA topology of those platform devices are exported by firmware as > well. Software might care about the numa_node of those devices in order to achieve > NUMA locality.
Is it generally the case that the SMMU will be in the same NUMA node as the endpoint device (which you're driving)? If so, we can get this info from sysfs already for the endpoint, and also have a link from the endpoint to the iommu for pci devices (which I assume you're interested in):
root@(none)$ ls -l /sys/devices/pci0000:74/0000:74:02.0/ | grep iommu lrwxrwxrwx 1 root root 0 Jun 22 10:33 iommu -> ../../platform/arm-smmu-v3.2.auto/iommu/smmu3.0x0000000140000000 lrwxrwxrwx 1 root root 0 Jun 22 10:33 iommu_group -> ../../../kernel/iommu_groups/0 root@(none)$
Thanks, John
| |