On 27.06.24 02:54, Alistair Popple wrote:
Longterm pinning of FS DAX pages should already be disallowed by various pXX_devmap checks. However a future change will cause these checks to be invalid for FS DAX pages so make folio_is_longterm_pinnable() return false for FS DAX pages.Signed-off-by: Alistair Popple <apop...@nvidia.com> --- include/linux/memremap.h | 11 +++++++++++ include/linux/mm.h | 4 ++++ 2 files changed, 15 insertions(+) diff --git a/include/linux/memremap.h b/include/linux/memremap.h index 6505713..19a448e 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -193,6 +193,17 @@ static inline bool folio_is_device_coherent(const struct folio *folio) return is_device_coherent_page(&folio->page); }+static inline bool is_device_dax_page(const struct page *page)+{ + return is_zone_device_page(page) && + page_dev_pagemap(page)->type == MEMORY_DEVICE_FS_DAX; +} + +static inline bool folio_is_device_dax(const struct folio *folio) +{ + return is_device_dax_page(&folio->page); +} + #ifdef CONFIG_ZONE_DEVICE void zone_device_page_init(struct page *page); void *memremap_pages(struct dev_pagemap *pgmap, int nid); diff --git a/include/linux/mm.h b/include/linux/mm.h index b84368b..4d1cdea 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2032,6 +2032,10 @@ static inline bool folio_is_longterm_pinnable(struct folio *folio) if (folio_is_device_coherent(folio)) return false;+ /* DAX must also always allow eviction. */+ if (folio_is_device_dax(folio)) + return false; + /* Otherwise, non-movable zone folios can be pinned. */ return !folio_is_zone_movable(folio);
Why is the check in check_vma_flags() insufficient? GUP-fast maybe? -- Cheers, David / dhildenb
