search for: dax_mapping

...K_INTERRUPTIBLE, + dax_layout_is_idle_page(page), TASK_INTERRUPTIBLE, 0, 0, xfs_wait_dax_page(inode)); } diff --git a/include/linux/dax.h b/include/linux/dax.h index 43b39ab9de1a..3f78ed78d1d6 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -238,4 +238,9 @@ static inline bool dax_mapping(struct address_space *mapping) return mapping->host && IS_DAX(mapping->host); } +static inline bool dax_layout_is_idle_page(struct page *page) +{ + return page_ref_count(page) <= 1; +} + #endif -- 2.20.1

...page); > + init_page_count(page); > lock_page(page); > return page; > } > diff --git a/include/linux/dax.h b/include/linux/dax.h > index 3f78ed78d1d6..8d29f38645aa 100644 > --- a/include/linux/dax.h > +++ b/include/linux/dax.h > @@ -240,7 +240,7 @@ static inline bool dax_mapping(struct address_space *mapping) > > static inline bool dax_layout_is_idle_page(struct page *page) > { > - return page_ref_count(page) <= 1; > + return page_ref_count(page) == 0; > } > > #endif > diff --git a/include/linux/memremap.h b/include/linux/memremap.h &g...

Matthew Wilcox, Ira Weiny, and others have complained that ZONE_DEVICE struct page reference counting is ugly because they are "free" when the reference count is one instead of zero. This leads to explicit checks for ZONE_DEVICE pages in places like put_page(), GUP, THP splitting, and page migration which have to adjust the expected reference count when determining if the page is

...RUPTIBLE, - 0, 0, xfs_wait_dax_page(inode)); + return dax_wait_page(inode, page, xfs_wait_dax_page); } int diff --git a/include/linux/dax.h b/include/linux/dax.h index b52f084aa643..f906cf4db1cc 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -243,6 +243,16 @@ static inline bool dax_mapping(struct address_space *mapping) return mapping->host && IS_DAX(mapping->host); } +static inline bool dax_layout_is_idle_page(struct page *page) +{ + return page_ref_count(page) == 1; +} + +#define dax_wait_page(_inode, _page, _wait_cb) \ + ___wait_var_event(&(_page)->_re...

...NTERRUPTIBLE, > 0, 0, xfs_wait_dax_page(inode)); > } > > diff --git a/include/linux/dax.h b/include/linux/dax.h > index 43b39ab9de1a..3f78ed78d1d6 100644 > --- a/include/linux/dax.h > +++ b/include/linux/dax.h > @@ -238,4 +238,9 @@ static inline bool dax_mapping(struct address_space *mapping) > return mapping->host && IS_DAX(mapping->host); > } > > +static inline bool dax_layout_is_idle_page(struct page *page) > +{ > + return page_ref_count(page) <= 1; Why convert the check from "== 1" to "&...

This is still an RFC because after looking at the pmem/dax code some more, I realized that the ZONE_DEVICE struct pages are being inserted into the process' page tables with vmf_insert_mixed() and a zero refcount on the ZONE_DEVICE struct page. This is sort of OK because insert_pfn() increments the reference count on the pgmap which is what prevents memunmap_pages() from freeing the struct

..._drm *drm) return NULL; } - get_page(page); + init_page_count(page); lock_page(page); return page; } diff --git a/include/linux/dax.h b/include/linux/dax.h index 3f78ed78d1d6..8d29f38645aa 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -240,7 +240,7 @@ static inline bool dax_mapping(struct address_space *mapping) static inline bool dax_layout_is_idle_page(struct page *page) { - return page_ref_count(page) <= 1; + return page_ref_count(page) == 0; } #endif diff --git a/include/linux/memremap.h b/include/linux/memremap.h index e5862746751b..f9224f88e4cd 100644 --- a/i...

...face to determine if * any page in the mapping is busy, i.e. for DMA, or other * get_user_pages() usages. * diff --git a/include/linux/dax.h b/include/linux/dax.h index f906cf4db1cc..e4920ea6abd3 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -245,7 +245,7 @@ static inline bool dax_mapping(struct address_space *mapping) static inline bool dax_layout_is_idle_page(struct page *page) { - return page_ref_count(page) == 1; + return page_ref_count(page) == 0; } #define dax_wait_page(_inode, _page, _wait_cb) \ diff --git a/include/linux/memremap.h b/include/linux/memremap.h index...