On Fri, Aug 7, 2015 at 11:41 AM, Ross Zwisler <[email protected]> wrote: > On Fri, 2015-08-07 at 09:14 -0700, Dan Williams wrote: >> On Thu, Aug 6, 2015 at 10:43 AM, Ross Zwisler >> <[email protected]> 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. > > I think that we should only keep around functions that are actually used and > useful. I agree that there could potentially be a use for a distinction like > the one you are talking about when we try and properly support ADR systems and > stop lumping them in with "non-PCOMMIT" systems like we are doing now. > > Right now, though, arch_has_wmb_pmem() is just redundant. If/when we add that > new support in, we'll have to properly update this code anyway - let's not > keep around unneeded code until then.
I don't see the pain in carrying around one unused static inline especially if we'll have a use for it in the near term. But, if it needs to go then __arch_has_wmb_pmem() needs to be renamed to drop the "__" since there is no longer a wrapper. -- 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/
