On Fri, Mar 27, 2020 at 04:42:48AM -0400, Jeff King wrote: > On Tue, Mar 24, 2020 at 05:08:26PM -0600, Taylor Blau wrote: > > I can plan to deploy this patch to GitHub's servers for a ~month and > > see if we experience it. > > ...I don't think we'll actually generate good data here. We're probably > going to end up doing our "big maintenance" commit-graph roll-ups by > just feeding --reachable as input, and dropping all of the existing > graphs. For what it's worth (and I'm not sure that it's worth much), but this is only true in the last day or so. Before, we were running: $ git commit-graph write --split=merge-all --input=none which *did* exercise this code quite frequently (and thus would have been helped by this patch). But now, we are running something like: $ git commit-graph write --split=replace --input=reachable ...where '--split=replace' means "write a split commit-graph, but drop all existing layers before writing it". This case is obviously not helped by this patch, although I think the patch is worthwhile for callers who do the first thing. I'll post patches about that shortly after they've been a little more well-vetted (we're only generating split commit-graphs on a percentage of repositories for now). > -Peff Thanks, Taylor
