On Mon, Mar 27, 2017 at 09:09:37PM +0000, git@xxxxxxxxxxxxxxxxx wrote: > From: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx> > > Version 2 of this patch series simplifies this to just > turn off the hash verification. Independent comments > from Linus and Peff suggested that we could just turn > this off and not worry about it. So I've updated this > patch to do that. I added a global variable to allow > the original code path to be used. I also added a > t/helper command to demonstrate the differences. > > On the Linux repo, the effect is rather trivial: > > $ ~/work/gfw/t/helper/test-skip-verify-index -c 3 > 0.029884 0 [cache_nr 57994] > 0.031035 0 [cache_nr 57994] > 0.024308 0 [cache_nr 57994] > 0.028409 0 avg > 0.018359 1 [cache_nr 57994] > 0.017025 1 [cache_nr 57994] > 0.011087 1 [cache_nr 57994] > 0.015490 1 avg > > On my Windows source tree (450MB index), I'm seeing a > savings of 0.6 seconds -- read_index() went from 1.2 to 0.6 > seconds. Very satisfying. I assume that was with OpenSSL as the SHA-1 implementation (sha1dc would have been much slower on 450MB, I think). -Peff