On Sat, Feb 16, 2019 at 09:29:48AM -0800, Matthew Wilcox wrote: > On Sat, Feb 16, 2019 at 07:35:11AM -0800, Matthew Wilcox wrote: > > Another way to fix this would be to mask the address in dax_entry_mkclean(), > > but I think this is cleaner. > > That's clearly rubbish, dax_entry_mkclean() can't possibly mask the > address. It might be mis-aligned in another process. But ... if it's > misaligned in another process, dax_entry_mkclean() will only clean the first > PTE associated with the PMD; it won't clean the whole thing. I think we need > something like this:
Nope, this isn't enough. It's _necessary_ to find the processes that have part of this PMD page mapped, but not the start of it. But it's not _sufficient_ because it'll still only mkclean the first PTE. So we need a loop. I'm feeling a bit over my head here. I may have a go at a fuller fix, but if someone else wants to have a go at it, be my guest! (feeling massively unqualified for the task at hand ;-)
