On 3/9/21 9:41 AM, Oscar Salvador wrote: > When sizeof(struct page) is not a power of 2, sections do not span > a PMD anymore and so when populating them some parts of the PMD will > remain unused. > Because of this, PMDs will be left behind when depopulating sections > since remove_pmd_table() thinks that those unused parts are still in > use. > > Fix this by marking the unused parts with PAGE_UNUSED, so memchr_inv() > will do the right thing and will let us free the PMD when the last user > of it is gone. > > This patch is based on a similar patch by David Hildenbrand: > > https://lore.kernel.org/linux-mm/20200722094558.9828-9-david@xxxxxxxxxx/ Looks good now. It's much easier to read without the optimization. Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
