On 02/21/2018 09:15 AM, Khalid Aziz wrote: > If a processor supports special metadata for a page, for example ADI > version tags on SPARC M7, this metadata must be saved when the page is > swapped out. The same metadata must be restored when the page is swapped > back in. This patch adds two new architecture specific functions - > arch_do_swap_page() to be called when a page is swapped in, and > arch_unmap_one() to be called when a page is being unmapped for swap > out. These architecture hooks allow page metadata to be saved if the > architecture supports it. I still think silently squishing cacheline-level hardware data into page-level software data structures is dangerous. But, you seem rather determined to do it this way. I don't think this will _hurt_ anyone else, though other than needlessly cluttering up the code.