On Thu, Apr 18, 2019 at 09:05:05AM -0700, Dan Williams wrote: > > > I'd either add a comment about avoiding retpoline overhead here or just > > > make ->flush == NULL mean generic_nvdimm_flush(). Just so that people don't > > > get confused by the code. > > > > Isn't this premature optimization? I really don't like adding things > > like this without some numbers to show it's worth it. > > I don't think it's premature given this optimization technique is > already being deployed elsewhere, see: > > https://lwn.net/Articles/774347/ For one this one was backed by numbers, and second after feedback from Linux we switched to the NULL pointer check instead.
