On 1/22/26 19:00, Vlastimil Babka wrote: > On 1/22/26 08:19, Matthew Brost wrote: >> On Tue, Jan 20, 2026 at 10:01:18PM -0500, Zi Yan wrote: >>> On 20 Jan 2026, at 8:53, Jason Gunthorpe wrote: >>> >> >> This whole thread makes my head hurt, as does core MM. >> >> IMO the TL;DR is: >> >> - Why is Intel the only one proving this stuff works? We can debate all >> day about what should or should not work — but someone else needs to >> actually prove it.i, rather than type hypotheticals. >> >> - Intel has demonstrated that this works and is still getting blocked. >> >> - This entire thread is about a fixes patch for large device pages. >> Changing prep_compound_page is completely out of scope for a fixes >> patch, and honestly so is most of the rest of what’s being proposed. > > FWIW I'm ok if this lands as a fix patch, and perceived the discussion to be > about how refactor things more properly afterwards, going forward. >
I've said the same thing and I concur, we can use the patch as-is and change this to set the relevant identified fields after 6.19 Balbir >> - At a minimum, you must clear every page’s flags in the loop. So why not >> conservatively clear anything else a folio might have set before calling >> an existing core-MM function, ensuring the pages are in a known state? >> This is a fixes patch. >> >> - Given the current state of the discussion, I don’t think large device >> pages should be in 6.19. And if so, why didn’t the entire device pages >> series receive this level of scrutiny earlier? It’s my mistake for not >> saying “no” until the reallocation at different sizes issue was resolved. >> >> @Andrew. - I'd revert large device pages in 6.19 as it doesn't work and >> we seemly cannot close on this. >> >> Matt <snip>
