Playing with different memory sizes for a x86-64 guest, I discovered that some memmaps (highest section if max_mem does not fall on the section boundary) are marked as being valid and online, but contain garbage. We have to properly initialize these memmaps. Looking at /proc/kpageflags and friends, I found some more issues, partially related to this. v1 -> v2: - "mm: fix uninitialized memmaps on a partially populated last section" -- Refine patch description (esp. how to reproduce), add tested-by - "fs/proc/page.c: allow inspection of last section and fix end detection" -- Make it compile for !CONFIG_SPARSE and add a comment to the new helper function David Hildenbrand (3): mm: fix uninitialized memmaps on a partially populated last section fs/proc/page.c: allow inspection of last section and fix end detection mm: initialize memmap of unavailable memory directly fs/proc/page.c | 30 +++++++++++++++++++++++++++--- include/linux/mm.h | 6 ------ mm/page_alloc.c | 43 ++++++++++++++++++++++++++++++++----------- 3 files changed, 59 insertions(+), 20 deletions(-) -- 2.23.0
