This addresses several issues with hugepages and memory offline. While the first patch fixes a panic, and is therefore rather important, the last patch is just a performance optimization.
The second patch fixes a theoretical issue with reserved hugepages, while still leaving some ugly usability issue, see description. Changes in v4: - Add check for free vs. reserved hugepages - Revalidate checks in dissolve_free_huge_page() after taking the lock - Split up into 3 patches Changes in v3: - Add Fixes: c8721bbb - Add Cc: stable - Elaborate on losing the gigantic page vs. failing memory offline - Move page_count() check out of dissolve_free_huge_page() Changes in v2: - Update comment in dissolve_free_huge_pages() - Change locking in dissolve_free_huge_page() Gerald Schaefer (3): mm/hugetlb: fix memory offline with hugepage size > memory block size mm/hugetlb: check for reserved hugepages during memory offline mm/hugetlb: improve locking in dissolve_free_huge_pages() include/linux/hugetlb.h | 6 +++--- mm/hugetlb.c | 47 +++++++++++++++++++++++++++++++++++------------ mm/memory_hotplug.c | 4 +++- 3 files changed, 41 insertions(+), 16 deletions(-) -- 2.8.4
