On Fri, Feb 12, 2016 at 10:36:25AM -0800, Dave Hansen wrote: > On 02/11/2016 06:21 AM, Kirill A. Shutemov wrote: > > File COW for THP is handled on pte level: just split the pmd. > > More changelog. More comments, please.
Okay, I'll add more. > We don't want to COW THP's because we'll waste memory? A COW that we > could handle with 4k, we would have to handle with 2M, and that's > inefficient and high-latency? All of above.i It's not clear how benefitial THP file COW mappings. And it would require some code to make them work. I think at some point we can consider teaching khugepaged to collapse such pages, but allocating huge on fault is probably overkill. > Seems like a good idea to me. It would just be nice to ensure every > reviewer doesn't have to think their way through it. -- Kirill A. Shutemov
