On Sat, Jun 24, 2017 at 02:12:07PM +0200, René Scharfe wrote: > Am 23.06.2017 um 01:10 schrieb Jeff King: > > On Thu, Jun 22, 2017 at 08:19:48PM +0200, René Scharfe wrote: > > > >> Read each loose object subdirectory at most once when looking for unique > >> abbreviated hashes. This speeds up commands like "git log --pretty=%h" > >> considerably, which previously caused one readdir(3) call for each > >> candidate, even for subdirectories that were visited before. > > > > Is it worth adding a perf test that's heavy on abbreviations? > > Sure. Here's a simple one. It currently reports for me: > > Test origin/master origin/next origin/pu > --------------------------------------------------------------------------------------------- > 4205.1: log with %H 0.44(0.41+0.02) 0.43(0.42+0.01) -2.3% 0.43(0.43+0.00) -2.3% > 4205.2: log with %h 1.03(0.60+0.42) 1.04(0.64+0.39) +1.0% 0.57(0.55+0.01) -44.7% > 4205.3: log with %T 0.43(0.42+0.00) 0.43(0.42+0.01) +0.0% 0.43(0.40+0.02) +0.0% > 4205.4: log with %t 1.05(0.64+0.38) 1.05(0.61+0.42) +0.0% 0.59(0.58+0.00) -43.8% > 4205.5: log with %P 0.45(0.42+0.02) 0.43(0.42+0.00) -4.4% 0.43(0.42+0.01) -4.4% > 4205.6: log with %p 1.21(0.63+0.57) 1.17(0.68+0.47) -3.3% 0.59(0.58+0.00) -51.2% > 4205.7: log with %h-%h-%h 1.05(0.64+0.39) 2.00(0.83+1.15) +90.5% 0.69(0.66+0.02) -34.3% > > origin/next has fe9e2aefd4 (pretty: recalculate duplicate short hashes), > while origin/pu has cc817ca3ef (sha1_name: cache readdir(3) results in > find_short_object_filename()). Perfect. That last one says everything we need to know about which approach to take. :) -Peff
