Re: Performance issue of 'git branch'
From: Carlos R. Mafra <hidden>
Date: 2016-06-15 22:47:05
On Thu 23.Jul'09 at 12:48:20 -0400, Anders Kaseorg wrote:
I submitted essentially the same patch in May: http://article.gmane.org/gmane.comp.version-control.git/120097 with the additional optimization that we don't need to lookup commits at all unless we're using -v, --merged, --no-merged, or --contains. In my tests, it makes `git branch` 5 times faster on an uncached linux-2.6 repository.
I also tested your patch even if you said that it was "essentially the same". But after repeating the tests 6 times for both your and Linus' patch (taking care to let the system rest a bit after clearing the cache), your patch is faster, 0.62 +/- 0.24 (Anders) 1.35 +/- 0.23 (Linus) And this is the raw data for your patch, 0.00user 0.01system 0:00.54elapsed 2%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (7major+727minor)pagefaults 0swaps 0.00user 0.00system 0:00.18elapsed 5%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (1major+733minor)pagefaults 0swaps 0.00user 0.00system 0:00.66elapsed 1%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (9major+723minor)pagefaults 0swaps 0.00user 0.01system 0:00.74elapsed 2%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (14major+720minor)pagefaults 0swaps 0.00user 0.00system 0:00.80elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (16major+718minor)pagefaults 0swaps 0.00user 0.00system 0:00.83elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (16major+718minor)pagefaults 0swaps and for Linus' 0.00user 0.01system 0:01.56elapsed 1%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (43major+755minor)pagefaults 0swaps 0.00user 0.01system 0:01.09elapsed 1%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (24major+775minor)pagefaults 0swaps 0.00user 0.01system 0:01.33elapsed 1%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (32major+767minor)pagefaults 0swaps 0.00user 0.00system 0:01.53elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (39major+760minor)pagefaults 0swaps 0.00user 0.01system 0:01.06elapsed 2%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (24major+775minor)pagefaults 0swaps 0.00user 0.00system 0:01.54elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (39major+760minor)pagefaults 0swaps