On Wed, Nov 18, 2015 at 1:11 PM, Jeff King <peff@xxxxxxxx> wrote: > On Wed, Nov 18, 2015 at 01:32:36PM +0100, Duy Nguyen wrote: > >> Yeah I think that was the 10k commits in Shawn's mail: the number of >> commits we may have to walk until we hit a reachability bitmap. It >> looks like C Git will create a bitmap every 5k commits, not 10k, >> though, if I read the code correctly. The point is reachability test >> with the presence of pack bitmaps is not O(n) anymore. Which is >> probably good enough for now. > > There are some pathological cases, though. I hit one recently that still > took 40s to do "rev-list --objects --all --use-bitmap-index" (it's 80s > without bitmaps). The problem is that it has over 20,000 refs. We try > to put a bitmap at the tip of each ref, but it's tough when there are > that many. +Terry, who did optimize the JGit implementation for bitmaps, as we also had a "lots of refs" hoarder repo, which underperformed before. > > I suspect there's room for improvement in the commit selection in such > cases. That code hasn't really been tweaked since it was originally > written, and repositories like that are extreme outliers. > > -Peff -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html