On 16.12.16 09:57:20, Hanjun Guo wrote:

Hi Robert,

On 2016/12/15 23:39, Robert Richter wrote:

quoted

I was going to do some measurements but my kernel crashes now with a
page fault in efi_rtc_probe():

[   21.663393] Unable to handle kernel paging request at virtual address 20251000
[   21.663396] pgd = ffff000009090000
[   21.663401] [20251000] *pgd=0000010ffff90003
[   21.663402] , *pud=0000010ffff90003
[   21.663404] , *pmd=0000000fdc030003
[   21.663405] , *pte=00e8832000250707

The sparsemem config requires the whole section to be initialized.
Your patches do not address this.

This patch set is running properly on D05, both the boot and
LTP MM stress test are ok, seems it's a different configuration
of memory mappings in firmware, just a stupid question, which
part is related to this problem, is it only the Reserved memory?

The problem are efi reserved regions that are no longer reserved but
marked as nomap pages. Those are excluded from page initialization
causing parts of a memory section not being initialized.

-Robert