On Thu, 6 Sep 2007, Junio C Hamano wrote: > > I thought the whole point of "gc --auto" was to have something > that does not lose/prune any objects, even the ones that do not > seem to be referenced from anywhere. That is why invocations of > "git gc --auto" do not say --prune as you saw the second patch, > and the repack command "gc --auto" runs is "repack -d -l" > instead of "repack -a -d -l", which means that it does run > git-prune-packed after repacking but not git-prune. I think "repack -d -l" should be ok from a safety perspective, but I'd also like to say that always running it incrementally is going to largely suck after a time. IOW, if you get lots of small incrmental packs, after a while you really *do* need to do "git gc" to get the real pack generated. In the case I saw, James really had hundreds of pack-files. That makes all our object lookups suck. Yes, not having loose objects at all is a big deal too, and yes, we try to start from the last pack-file we found (for the locality that we hope is there), but it's still pretty bad from a cache usage standpoint, and when we create a new object, we'll first search (in vain) in all the hundreds of pack-files. So would "git gc --auto" have helped James? I'm sure it would have. But he already had lots of pack-files from doing "git fetch/pull", and while doing the "git gc --auto" will likely *delay* the point where you need to do a full repack, it doesn't make it go away. We still need to tell people to do a full git gc at some point, or do it for them. And the longer you delay doing it, the more expensive it's going to get to do and/or the worse the final packing is going to be (especially if it ends up reusing non-optimal packing decisions from the smaller packs). So I think the --auto stuff is still worth it, but it's really just pushing the pain somewhat further out. (In the kernel community, if you fetch my tree daily, you really *are* going to have hundreds and hundreds of packfiles just from doing that). So I'd really like us to also remind people to do a *real* and full "git gc", not just the incremental ones. Linus - 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
