Re: AMD GPU driver load hitting BUG_ON in sync_global_pgds_l5()

From: Bharata B Rao
Date: Thu Apr 24 2025 - 08:54:37 EST




On 23-Apr-25 9:31 PM, Dave Hansen wrote:
On 4/23/25 02:30, Bharata B Rao wrote:
On 22-Apr-25 8:43 PM, Dave Hansen wrote:
On 4/21/25 23:34, Bharata B Rao wrote:
At the outset, it appears that the selection of vmemmap_base doesn't
seem to consider if there is going to be enough room of accommodating
future hot plugged pages.

Is this future hotplug area in the memory map at boot?

The KVM guest isn't using any -m maxmem option if that's what you are
hinting at.

How could vmemmap_base consider future hotplug areas if it isn't told
where they will be?

This is device private memory which means only struct pages need to be mapped. What's the way by which kernel will know about the future growth in the number of struct pages to accommodate the incoming device private memory?

In any case, how can kaslr put vmemmap_base completely out of the range earmarked for it in mm.rst?

Regards,
Bharata.