Messages in this thread | | | Subject | Re: [PATCH v2 1/3] mm: document zone device struct page field usage | From | Ralph Campbell <> | Date | Tue, 23 Jul 2019 14:25:43 -0700 |
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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)?
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