diff options
| author | Joao Martins <joao.m.martins@oracle.com> | 2022-01-14 14:04:47 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-15 16:30:26 +0200 |
| commit | 14606001efb48a17be31a5bec626c13ca49d783a (patch) | |
| tree | 0ca8883b1b1050c53ae3cd76472704085d6c4275 /drivers/dax | |
| parent | 6ec228b6fef5ad3a1f19e76c29640a9161415240 (diff) | |
device-dax: compound devmap support
Use the newly added compound devmap facility which maps the assigned dax
ranges as compound pages at a page size of @align.
dax devices are created with a fixed @align (huge page size) which is
enforced through as well at mmap() of the device. Faults, consequently
happen too at the specified @align specified at the creation, and those
don't change throughout dax device lifetime. MCEs unmap a whole dax
huge page, as well as splits occurring at the configured page size.
Performance measured by gup_test improves considerably for
unpin_user_pages() and altmap with NVDIMMs:
$ gup_test -f /dev/dax1.0 -m 16384 -r 10 -S -a -n 512 -w
(pin_user_pages_fast 2M pages) put:~71 ms -> put:~22 ms
[altmap]
(pin_user_pages_fast 2M pages) get:~524ms put:~525 ms -> get: ~127ms put:~71ms
$ gup_test -f /dev/dax1.0 -m 129022 -r 10 -S -a -n 512 -w
(pin_user_pages_fast 2M pages) put:~513 ms -> put:~188 ms
[altmap with -m 127004]
(pin_user_pages_fast 2M pages) get:~4.1 secs put:~4.12 secs -> get:~1sec put:~563ms
.. as well as unpin_user_page_range_dirty_lock() being just as effective
as THP/hugetlb[0] pages.
[0] https://lore.kernel.org/linux-mm/20210212130843.13865-5-joao.m.martins@oracle.com/
Link: https://lkml.kernel.org/r/20211202204422.26777-12-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/dax')
| -rw-r--r-- | drivers/dax/device.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/dax/device.c b/drivers/dax/device.c index 60d43cb195da..591f293d326f 100644 --- a/drivers/dax/device.c +++ b/drivers/dax/device.c @@ -78,14 +78,20 @@ static void dax_set_mapping(struct vm_fault *vmf, pfn_t pfn, { unsigned long i, nr_pages = fault_size / PAGE_SIZE; struct file *filp = vmf->vma->vm_file; + struct dev_dax *dev_dax = filp->private_data; pgoff_t pgoff; + /* mapping is only set on the head */ + if (dev_dax->pgmap->vmemmap_shift) + nr_pages = 1; + pgoff = linear_page_index(vmf->vma, ALIGN(vmf->address, fault_size)); for (i = 0; i < nr_pages; i++) { struct page *page = pfn_to_page(pfn_t_to_pfn(pfn) + i); + page = compound_head(page); if (page->mapping) continue; @@ -443,6 +449,9 @@ int dev_dax_probe(struct dev_dax *dev_dax) } pgmap->type = MEMORY_DEVICE_GENERIC; + if (dev_dax->align > PAGE_SIZE) + pgmap->vmemmap_shift = + order_base_2(dev_dax->align >> PAGE_SHIFT); addr = devm_memremap_pages(dev, pgmap); if (IS_ERR(addr)) return PTR_ERR(addr); |