Messages in this thread | | | Date | Mon, 29 Aug 2016 23:48:42 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH v4 RESEND 0/2] Align mmap address for DAX pmd mappings |
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On Mon, Aug 29, 2016 at 01:11:19PM -0600, Toshi Kani wrote: > When CONFIG_FS_DAX_PMD is set, DAX supports mmap() using pmd page > size. This feature relies on both mmap virtual address and FS > block (i.e. physical address) to be aligned by the pmd page size. > Users can use mkfs options to specify FS to align block allocations. > However, aligning mmap address requires code changes to existing > applications for providing a pmd-aligned address to mmap(). > > For instance, fio with "ioengine=mmap" performs I/Os with mmap() [1]. > It calls mmap() with a NULL address, which needs to be changed to > provide a pmd-aligned address for testing with DAX pmd mappings. > Changing all applications that call mmap() with NULL is undesirable. > > This patch-set extends filesystems to align an mmap address for > a DAX file so that unmodified applications can use DAX pmd mappings.
+Hugh
Can we get it used for shmem/tmpfs too? I don't think we should duplicate essentially the same functionality in multiple places.
-- Kirill A. Shutemov
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