On 9/27/2021 6:51 PM, David Hildenbrand wrote:

On 24.09.21 00:54, Chris Goldsworthy wrote:

quoted

From: Sudarshan Rajagopalan <redacted>

After new memory blocks have been hotplugged, max_pfn and max_low_pfn
needs updating to reflect on new PFNs being hot added to system.

Signed-off-by: Sudarshan Rajagopalan <redacted>
Signed-off-by: Chris Goldsworthy <redacted>
---
  arch/arm64/mm/mmu.c | 5 +++++
  1 file changed, 5 insertions(+)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index cfd9deb..fd85b51 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c

@@ -1499,6 +1499,11 @@ int arch_add_memory(int nid, u64 start, u64 size,

      if (ret)
          __remove_pgd_mapping(swapper_pg_dir,
                       __phys_to_virt(start), size);
+    else {
+        max_pfn = PFN_UP(start + size);
+        max_low_pfn = max_pfn;
+    }
+
      return ret;

Note: didn't verify if updating max_low_pfn is correct here.

My understanding is that max_low_pfn defines the low/high memory
boundary and it should be also updated.

Thanks,
Georgi