Re: [PATCH 0/6] mm: make movable onlining suck less

[Reza Arbab <arbab@linux.vnet.ibm.com>]

On Tue, Apr 04, 2017 at 06:44:53PM +0200, Michal Hocko wrote:
>Thanks for your testing! This is highly appreciated.
>Can I assume your Tested-by?

Of course! Not quite done, though. I think I found another edge case.  
You get an oops when removing all of a node's memory:

__nr_to_section
__pfn_to_section
find_biggest_section_pfn
shrink_pgdat_span
__remove_zone
__remove_section
__remove_pages
arch_remove_memory
remove_memory

I stuck some debugging prints in, for context:

shrink_pgdat_span: start_pfn=0x10000, end_pfn=0x10100, pgdat_start_pfn=0x0, pgdat_end_pfn=0x20000
shrink_pgdat_span: start_pfn=0x10100, end_pfn=0x10200, pgdat_start_pfn=0x0, pgdat_end_pfn=0x20000
...%<...
shrink_pgdat_span: start_pfn=0x1fe00, end_pfn=0x1ff00, pgdat_start_pfn=0x0, pgdat_end_pfn=0x20000
shrink_pgdat_span: start_pfn=0x1ff00, end_pfn=0x20000, pgdat_start_pfn=0x0, pgdat_end_pfn=0x20000
find_biggest_section_pfn: start_pfn=0x0, end_pfn=0x1ff00
find_biggest_section_pfn loop: pfn=0x1feff, sec_nr = 0x1fe
find_biggest_section_pfn loop: pfn=0x1fdff, sec_nr = 0x1fd
...%<...
find_biggest_section_pfn loop: pfn=0x1ff, sec_nr = 0x1
find_biggest_section_pfn loop: pfn=0xff, sec_nr = 0x0
find_biggest_section_pfn loop: pfn=0xffffffffffffffff, sec_nr = 0xffffffffffffff
Unable to handle kernel paging request for data at address 0xc000800000f19e78


-- 
Reza Arbab