On 05/17/2018 11:24 PM, Michal Hocko wrote: > On Fri 18-05-18 11:03:16, Huang, Ying wrote: > [...] >> The patch is a generic optimization which should benefit quite some >> workloads, not for a specific use case. To demonstrate the performance >> benefit of the patch, we tested it with vm-scalability run on >> transparent huge page. > > It is also adds quite some non-intuitive code. So is this worth? Does > any _real_ workload benefits from the change? One way to 'add less code' would be to create a helper routine that indicates the order in which sub-pages are to be copied. IIUC, you added the same algorithm for sub-page ordering to copy_huge_page() that was previously added to clear_huge_page(). Correct? If so, then perhaps a common helper could be used by both the clear and copy huge page routines. It would also make maintenance easier. -- Mike Kravetz
