On Thu 01-02-24 20:52:26, Lance Yang wrote: > The collapsing behavior of khugepaged with pages > marked using MADV_FREE might cause confusion > among users. > > For instance, allocate a 2MB chunk using mmap and > later release it by MADV_FREE. Khugepaged will not > collapse this chunk. From the user's perspective, > it treats lazyfree pages as pte_none. However, > for some pages marked as lazyfree with MADV_FREE, > khugepaged might collapse this chunk and copy > these pages to a new huge page. This inconsistency > in behavior could be confusing for users. Is that any more confusing than collapsing pte_none pages? TBH I do not really see why this is a problem. MADV_FREE are correctly recognized same as pte_none so the user defined trashold applies. -- Michal Hocko SUSE Labs
