On Thu, 2015-05-28 at 21:19 -0700, H. Peter Anvin wrote: > On 05/28/2015 05:02 PM, Dan Williams wrote: > > > > Hmm, yes, but I believe Ross (on vacation now) was following the > > precedent set by commit cd8ddf1a2800 "x86: clflush_page_range needs > > mfence" whereby the api handles all necessary fencing internally. > > Shall we introduce something like __unordered_clflush_cache_range() > > for arch_persistent_flush() to use with the understanding it will > > be > > following up with the wmb() in arch_persistent_sync()? > > > > Are we ever going to have arch_persistent_sync() without > arch_persistent_flush()? > > However, thinking about it, it would be more efficient to do all > flushes > first and then have a single barrier. Yep, we have arch_persistent_sync() without arch_persistent_flush() in both our PMEM and ND_BLK write paths. These use arch_persistent_copy() to get NT stores, so they don't need to manually flush/write-back before doing a persistent_sync(). -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
