On Fri, Aug 07, 2020 at 10:32:26AM -0700, Junio C Hamano wrote: > >> Test HEAD^ HEAD > >> -------------------------------------------------------------------- > >> 1400.2: update-ref 1.93(1.57+0.42) 1.91(1.55+0.42) -1.0% > >> 1400.3: update-ref --stdin 0.07(0.02+0.05) 0.07(0.02+0.05) +0.0% > >> > >> Running it a second time gets me +0.5%. :) > > > > Yeah, it's also been my take that OS-level overhead is probably going to > > matter more than those access calls, and I argued such back when I > > proposed the hook. So I'm perfectly happy to see this caching mechanism > > go. > > Is the above about negative cache? IOW, does the above demonstrate > that one extra access() to make sure there is no hook does not hurt > us anything? Yes, those numbers are with no cache at all, and without a hook. So they are measuring the cost of access() only. -Peff
