On 3/1/21 12:32 AM, Oscar Salvador wrote:

remove_pte_table() is prepared to handle the case where either the
start or the end of the range is not PAGE aligned.
This cannot actually happen:

__populate_section_memmap enforces the range to be PMD aligned,
so as long as the size of the struct page remains multiple of 8,
the vmemmap range will be aligned to PAGE_SIZE.

Drop the dead code and place a VM_BUG_ON in vmemmap_{populate,free}
to catch nasty cases.

I was wondering why the VM_BUG_ON()s went in vmemmap_free() instead of
closer to the code that you modified in remove_pte_table().  I assume
this was because vmemmap_free() is the only (indirect) caller of
remove_pte_table().

Otherwise, this looks fine to me:

Acked-by: Dave Hansen <dave.hansen@linux.intel.com>