On Thu, Aug 6, 2015 at 10:43 AM, Ross Zwisler <ross.zwis...@linux.intel.com> wrote: > Prior to this change arch_has_wmb_pmem() was only called by > arch_has_pmem_api(). Both arch_has_wmb_pmem() and arch_has_pmem_api() > checked to make sure that CONFIG_ARCH_HAS_PMEM_API was enabled. > > Instead, remove one extra layer of indirection and the redundant > CONFIG_ARCH_HAS_PMEM_API check, and just have arch_has_pmem_api() > call __arch_has_wmb_pmem() directly.
So I think this patch takes us further away from where we want to go in the near term which is a finer grained pmem api. The class of systems where (has_pmem_api() && !has_wmb_pmem()) is existing energy backed nvdimm platforms. I'm assuming those platforms will want to assert persistence guarantees in the absence of a pcommit-like instruction, and that we want to stop gating arch_has_pmem_api() on the presence of wmb_pmem() capability. In that case arch_has_wmb_pmem() will be useful to have and that was the original intent for including it, that intent did not seem to comprehended in the changelog. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
