On 09/27/2017 11:49 AM, Will Deacon wrote: > The moral of the story is that read-after-read (same address) ordering *only* > applies if READ_ONCE is used consistently. This means we need to fix page > table dereferences in the core code as well as the arch code to avoid this > problem. The two RFC patches in this series fix arm64 (which is a bigger fix > that necessary since I clean things up too) and page_vma_mapped_walk. > > Comments welcome.
Thanks for this Will. I'll echo Timur's comment that it would be ideal to split this up into the critical piece needed for ordering access/update to the PMD in the face of a THP split and separately have the cosmetic cleanups. Needless to say, we've got a bunch of people who are tracking this one and tracking it ready for backport. We just got THP re-enabled so I'm pretty keen that we not have to disable again. Jon. -- Computer Architect | Sent from my Fedora powered laptop
