> > On 7/22/19 4:08 AM, Matthew Wilcox wrote: > > On Sun, Jul 21, 2019 at 10:13:45PM -0700, Ira Weiny wrote: > >> On Sun, Jul 21, 2019 at 09:02:04AM -0700, Matthew Wilcox wrote: > >>> On Fri, Jul 19, 2019 at 12:29:53PM -0700, Ralph Campbell wrote: > >>>> Struct page for ZONE_DEVICE private pages uses the page->mapping > >>>> and and page->index fields while the source anonymous pages are > >>>> migrated to device private memory. This is so rmap_walk() can find > >>>> the page when migrating the ZONE_DEVICE private page back to system > memory. > >>>> ZONE_DEVICE pmem backed fsdax pages also use the page->mapping > and > >>>> page->index fields when files are mapped into a process address space. > >>>> > >>>> Restructure struct page and add comments to make this more clear. > >>> > >>> NAK. I just got rid of this kind of foolishness from struct page, > >>> and you're making it harder to understand, not easier. The comments > >>> could be improved, but don't lay it out like this again. > >> > >> Was V1 of Ralphs patch ok? It seemed ok to me. > > > > Yes, v1 was fine. This seems like a regression. > > > > This is about what people find "easiest to understand" and so I'm not > surprised that opinions differ. > What if I post a v3 based on v1 but remove the _zd_pad_* variables that > Christoph found misleading and add some more comments about how the > different ZONE_DEVICE types use the 3 remaining words (basically the > comment from v2)? I'm ok with that... Ira
