Shawn Pearce <spearce@xxxxxxxxxxx> writes: > On Sat, Apr 26, 2014 at 10:30 AM, David Kastrup <dak@xxxxxxx> wrote: >> David Kastrup <dak@xxxxxxx> writes: >> >> Here's some example: >> >> dak@lola:/usr/local/tmp/wortliste$ time git blame -n -s wortliste >/tmp/wl1 >> >> real 15m47.118s >> user 14m39.928s >> sys 1m1.872s > > Hah, this is quite the torture test. git before your patch is taking > 22m11s on my laptop to compute this. (This was with default options, I > noticed you passed -s to suppress the author formatting.) > >> dak@lola:/usr/local/tmp/wortliste$ time ../git/git blame -n -s wortliste >/tmp/wl2 >> >> real 3m40.947s >> user 2m40.296s >> sys 0m59.440s > > Meanwhile JGit computed in 4m30s on the same hardware. So I guess we > are "fine". At least the stuff I fixed with regard to performance would seem to be done right in JGit to start with. > Its still not as fast as I want it to be. :-) Most of the diff data/CRC is computed over and over because of the blackbox use of xdiff. And then the delta-chain storage is packing stuff based on CRCs as well (not sure whether it keeps them around for unpacking). So there is a lot that could likely be improved while keeping the same basic algorithms, by cracking open the black boxes of the xdiff engine and the delta-chain coding. -- David Kastrup -- 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