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| author | Dan Williams <dan.j.williams@intel.com> | 2016-09-07 08:51:21 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-24 10:09:29 +0200 |
| commit | 0fd86d80ffdd1829a71a281d7bda550477a44b59 (patch) | |
| tree | a820dc0f089f5f2fa8cebd0773f5fb4bf978720b /kernel | |
| parent | b4000d206c21d868f9598a6d7b2fee5d48f613ec (diff) | |
| download | lwn-0fd86d80ffdd1829a71a281d7bda550477a44b59.tar.gz lwn-0fd86d80ffdd1829a71a281d7bda550477a44b59.zip | |
mm: fix cache mode of dax pmd mappings
commit 9049771f7d5490a302589976984810064c83ab40 upstream.
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.
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Toshi Kani <toshi.kani@hpe.com>
Reported-by: Kai Zhang <kai.ka.zhang@oracle.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/memremap.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/memremap.c b/kernel/memremap.c index 017532193fb1..c2eb3a057764 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -253,6 +253,7 @@ static void devm_memremap_pages_release(struct device *dev, void *data) align_start = res->start & ~(SECTION_SIZE - 1); align_size = ALIGN(resource_size(res), SECTION_SIZE); arch_remove_memory(align_start, align_size); + untrack_pfn(NULL, PHYS_PFN(align_start), align_size); pgmap_radix_release(res); dev_WARN_ONCE(dev, pgmap->altmap && pgmap->altmap->alloc, "%s: failed to free all reserved pages\n", __func__); @@ -288,6 +289,7 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, struct percpu_ref *ref, struct vmem_altmap *altmap) { resource_size_t key, align_start, align_size, align_end; + pgprot_t pgprot = PAGE_KERNEL; struct dev_pagemap *pgmap; struct page_map *page_map; int error, nid, is_ram; @@ -363,6 +365,11 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, if (nid < 0) nid = numa_mem_id(); + error = track_pfn_remap(NULL, &pgprot, PHYS_PFN(align_start), 0, + align_size); + if (error) + goto err_pfn_remap; + error = arch_add_memory(nid, align_start, align_size, true); if (error) goto err_add_memory; @@ -383,6 +390,8 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, return __va(res->start); err_add_memory: + untrack_pfn(NULL, PHYS_PFN(align_start), align_size); + err_pfn_remap: err_radix: pgmap_radix_release(res); devres_free(page_map); |