Hi Dietmar,
On 2021/9/9 16:34, Dietmar Eggemann wrote:
Hi,
We are carrying out some NUMA related test activities (some of which we discussed on this forum) on the Taishan 2280 v2 server.
For those tests we need memory attached to all 4 NUMA nodes equally. That's why we added 2 extra 32GB memory modules to the existing 2.
The manual says that they should be placed into slot:
000 (CPU A) 100 (CPU A) 020 (CPU B) and 120 (CPU B).
BMC console as well as startup logs show that the memory modules get properly detected in these slots.
But after Linux booted we don't have the expected 32 GB per NUMA node. There is node 1 & 3 with 64GB and node 0 & 2 with no memory instead.
We didn't find any BIOS options which could explain this memory distribution.
Do you have any hints why this is happening? Any help with this issue is highly appreciated.
Maybe it's related to the VA_BITS you set in the kernel config, so if you using 39 bits VA, it will not cover all the PA ranges reported by the firmware, so please set VA_BITS to 42 or 48, such as CONFIG_ARM64_VA_BITS_48=y.
Please let me know if it works.
Thanks Hanjun