[resend PATCH v2 33/33] libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region

The pmem driver attaches to both persistent and volatile memory ranges advertised by the ACPI NFIT. When the region is volatile it is redundant to spend cycles flushing caches at fsync(). Check if the hosting region is volatile and do not set QUEUE_FLAG_WC if it is. Cc: Jan Kara Cc: Jeff Moyer C

[PATCH v2 33/33] libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region

The pmem driver attaches to both persistent and volatile memory ranges advertised by the ACPI NFIT. When the region is volatile it is redundant to spend cycles flushing caches at fsync(). Check if the hosting region is volatile and do not set QUEUE_FLAG_WC if it is. Cc: Jan Kara Cc: Jeff Moyer C