diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2018-05-16 11:46:08 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2018-05-22 06:59:39 -0700 |
| commit | e7638488434415aa478e78435cac8f0365737638 (patch) | |
| tree | 7ce50f0ed69889aa44cb0124451cf7a56b34eba6 /drivers/nvdimm/pfn_devs.c | |
| parent | 5981690ddb8f72f9546a2d017a914cf56095fc1f (diff) | |
| download | linux-rt-e7638488434415aa478e78435cac8f0365737638.tar.gz | |
mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS
In preparation for fixing dax-dma-vs-unmap issues, filesystems need to
be able to rely on the fact that they will get wakeups on dev_pagemap
page-idle events. Introduce MEMORY_DEVICE_FS_DAX and
generic_dax_page_free() as common indicator / infrastructure for dax
filesytems to require. With this change there are no users of the
MEMORY_DEVICE_HOST designation, so remove it.
The HMM sub-system extended dev_pagemap to arrange a callback when a
dev_pagemap managed page is freed. Since a dev_pagemap page is free /
idle when its reference count is 1 it requires an additional branch to
check the page-type at put_page() time. Given put_page() is a hot-path
we do not want to incur that check if HMM is not in use, so a static
branch is used to avoid that overhead when not necessary.
Now, the FS_DAX implementation wants to reuse this mechanism for
receiving dev_pagemap ->page_free() callbacks. Rework the HMM-specific
static-key into a generic mechanism that either HMM or FS_DAX code paths
can enable.
For ARCH=um builds, and any other arch that lacks ZONE_DEVICE support,
care must be taken to compile out the DEV_PAGEMAP_OPS infrastructure.
However, we still need to support FS_DAX in the FS_DAX_LIMITED case
implemented by the s390/dcssblk driver.
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Thomas Meyer <thomas@m3y3r.de>
Reported-by: Dave Jiang <dave.jiang@intel.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/nvdimm/pfn_devs.c')
| -rw-r--r-- | drivers/nvdimm/pfn_devs.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c index 30b08791597d..3f7ad5bc443e 100644 --- a/drivers/nvdimm/pfn_devs.c +++ b/drivers/nvdimm/pfn_devs.c @@ -561,8 +561,6 @@ static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap) res->start += start_pad; res->end -= end_trunc; - pgmap->type = MEMORY_DEVICE_HOST; - if (nd_pfn->mode == PFN_MODE_RAM) { if (offset < SZ_8K) return -EINVAL; |