On Wed, 07 Sep 2016 15:26:14 -0700 Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > track_pfn_insert() in vmf_insert_pfn_pmd() is marking dax mappings as > uncacheable rendering them impractical for application usage. DAX-pte > mappings are cached and the goal of establishing DAX-pmd mappings is to > attain more performance, not dramatically less (3 orders of magnitude). > > track_pfn_insert() relies on a previous call to reserve_memtype() to > establish the expected page_cache_mode for the range. While memremap() > arranges for reserve_memtype() to be called, devm_memremap_pages() does > not. So, teach track_pfn_insert() and untrack_pfn() how to handle > tracking without a vma, and arrange for devm_memremap_pages() to > establish the write-back-cache reservation in the memtype tree. Acked-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> I'll grab [2/2]. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>