On Wed, May 13, 2015 at 2:05 PM, Toshi Kani <[email protected]> wrote: > The pmem driver maps NVDIMM with ioremap_nocache() as we cannot > write back the contents of the CPU caches in case of a crash. > > This patch changes to use ioremap_wt(), which provides uncached > writes but cached reads, for improving read performance.
I'm thinking that for the libnd integration we don't want the pmem driver hard coding the cache-policy decision. This is something that should be specified to nd_pmem_region_create(). Especially considering that platform firmware tables (NFIT) may specify the cache policy for the range. As Matthew Wilcox mentioned offline we also must match the DAX-to-mmap cache policy with the policy for the driver mapping for architectures that are not capable of multiple mappings of the same physical address with different policies. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
