search for: dax_wait_pag

...node.c +++ b/fs/ext4/inode.c @@ -3926,10 +3926,7 @@ int ext4_break_layouts(struct inode *inode) if (!page) return 0; - error = ___wait_var_event(&page->_refcount, - atomic_read(&page->_refcount) == 1, - TASK_INTERRUPTIBLE, 0, 0, - ext4_wait_dax_page(ei)); + error = dax_wait_page(ei, page, ext4_wait_dax_page); } while (error == 0); return error; diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 3d1b95124744..a5304aaeaa3a 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -749,9 +749,7 @@ xfs_break_dax_layouts( return 0; *retry = true; - return __...

...return ___wait_var_event(&page->_refcount, > - atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE, > + dax_layout_is_idle_page(page), TASK_INTERRUPTIBLE, > 0, 0, xfs_wait_dax_page(inode)); > } I still think a litte helper macro would be nice here: #define dax_wait_page(_inode, _page, _wait_cb) \ ___wait_var_event(&(_page)->_refcount, \ atomic_read(&(_page)->_refcount) == 1, \ TASK_INTERRUPTIBLE, dax_layout_is_idle_page(_page), \ TASK_INTERRUPTIBLE, 0, 0, _wait_cb(_inode));

...ight be OK. I could use help testing these configurations. I have been able to successfully run xfstests on ext4 with the memmap kernel boot option to simulate pmem. Changes in v3: Rebase to linux-mm 5.9.0-rc7-mm1. Added a check for page_free() as suggested by Christoph Hellwig. Added a helper for dax_wait_page() as suggested by Christoph Hellwig. Changes in v2: One of the big changes in v2 is that devm_memremap_pages() and memremap_pages() now return the struct pages' reference count set to zero instead of one. Normally, get_page() will VM_BUG_ON_PAGE() if page->_refcount is zero. I didn't s...

...abd3 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 86c6c368ce9b..2f63747caf56 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -66,9 +66,10 @@ enum memory_type { struct dev_pagemap_ops { /* - * Called once the page refc...

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