On Wed, Jan 30, 2013 at 10:31:43AM +0700, Nguyen Thai Ngoc Duy wrote: > On Tue, Jan 29, 2013 at 4:14 PM, Jeff King <p...@peff.net> wrote: > > The timings from this one are roughly similar to what I posted earlier. > > Unlike the earlier version, this one keeps the data for a single commit > > together for better cache locality (though I don't think it made a big > > difference in my tests, since my cold-cache timing test ends up touching > > every commit anyway). The short of it is that for an extra 31M of disk > > space (~4%), I get a warm-cache speedup for "git rev-list --all" of > > ~4.2s to ~0.66s. > > Some data point on caching 1-parent vs 2-parent commits on webkit > repo, 26k commits. With your changes (caching 2-parent commits), the > .commits file takes 2241600 bytes. "rev-list --all --quiet":
Hmm. My webkit repo has zero merges in it (though it is the older svn-based one). What percentage of the one you have are merges? How does your 1-parent cache perform on something like git.git, where about 25% of all commits are merges? > The performance loss in 1-parent case is not significant while disk > saving is (although it'll be less impressive after you do Shawn's > suggestion not storing SHA-1 directly) Yeah, I think moving to offsets instead of sha1s is going to be a big enough win that it won't matter anymore. -Peff -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
