On Sun, Aug 26, 2018 at 01:37:41PM +0200, René Scharfe wrote: > Am 14.08.2018 um 03:58 schrieb Jeff King: > > Your suggestion can be implemented using khash (my patch below). > > > >> Before: > >> Benchmark #1: ./git-cat-file --batch-all-objects --buffer --unordered --batch-check='%(objectname)' > >> > >> Time (mean ± σ): 269.5 ms ± 26.7 ms [User: 247.7 ms, System: 21.4 ms] > >> > >> Range (min … max): 240.3 ms … 339.3 ms > >> > >> After: > >> Benchmark #1: ./git-cat-file --batch-all-objects --buffer --unordered --batch-check='%(objectname)' > >> > >> Time (mean ± σ): 224.2 ms ± 18.2 ms [User: 201.7 ms, System: 22.1 ms] > >> > >> Range (min … max): 205.0 ms … 259.0 ms > > > > Yeah. My best-of-five dropped from 300ms to 247ms. That 300 was using > > the memory pool, though khash's deletion strategy isn't all that > > different (the wasted memory hangs around until the next hash resize, > > but if you're evenly dropping and adding, you likely won't need to > > resize). > > With your khash patch: > > Benchmark #1: ./git-cat-file --batch-all-objects --buffer --unordered --batch-check='%(objectname)' > > Time (mean ± σ): 159.1 ms ± 20.5 ms [User: 140.3 ms, System: 18.5 ms] > > Range (min … max): 140.0 ms … 214.0 ms > > So it seems worth it. Hmm, that really does. Which is a shame, because I hoped that one day we could get rid of the nasty macro-infestation that is khash.h. But it really is a lot faster than the alternatives. > [...] I agree with all of your comments here. What I posted was just trying to do the least amount of work to get something we could time. Do you want to pick up this topic and carry it forward? -Peff
