On Mon, Jun 28 2021, Ævar Arnfjörð Bjarmason wrote: > On Mon, Jun 28 2021, Patrick Steinhardt wrote: > >> [[PGP Signed Part:Undecided]] >> In the case where git-receive-pack(1) receives only commands which >> delete references, then per technical specification the client MUST NOT >> send a packfile. As a result, we know that no new objects have been >> received, which makes it a moot point to check whether all received >> objects are fully connected. > > Is it just per specification, or do we also have assertions/tests for > what happens in that case? > >> [...] >> The following tests were executed on linux.git and back up above >> expectation: >> >> Test origin/master HEAD >> --------------------------------------------------------------------------------------------------------- >> 5400.4: empty receive-pack updated:new 178.36(428.22+164.36) 177.62(421.33+164.48) -0.4% >> 5400.7: clone receive-pack updated:new 0.10(0.08+0.02) 0.10(0.08+0.02) +0.0% >> 5400.9: clone receive-pack updated:main 0.10(0.08+0.02) 0.11(0.08+0.02) +10.0% >> 5400.11: clone receive-pack main~10:main 0.15(0.11+0.04) 0.15(0.10+0.05) +0.0% >> 5400.13: clone receive-pack :main 0.01(0.00+0.01) 0.01(0.01+0.00) +0.0% >> 5400.16: clone_bitmap receive-pack updated:new 0.10(0.07+0.02) 0.09(0.06+0.02) -10.0% >> 5400.18: clone_bitmap receive-pack updated:main 0.10(0.07+0.02) 0.10(0.08+0.02) +0.0% >> 5400.20: clone_bitmap receive-pack main~10:main 0.15(0.11+0.03) 0.15(0.12+0.03) +0.0% >> 5400.22: clone_bitmap receive-pack :main 0.02(0.01+0.01) 0.01(0.00+0.00) -50.0% >> 5400.25: extrarefs receive-pack updated:new 32.34(20.72+11.86) 32.56(20.82+11.95) +0.7% >> 5400.27: extrarefs receive-pack updated:main 32.42(21.02+11.61) 32.52(20.64+12.10) +0.3% >> 5400.29: extrarefs receive-pack main~10:main 32.53(20.74+12.01) 32.39(20.63+11.97) -0.4% >> 5400.31: extrarefs receive-pack :main 7.13(3.53+3.59) 7.15(3.80+3.34) +0.3% >> 5400.34: extrarefs_bitmap receive-pack updated:new 32.55(20.72+12.04) 32.65(20.68+12.18) +0.3% >> 5400.36: extrarefs_bitmap receive-pack updated:main 32.50(20.90+11.86) 32.67(20.93+11.94) +0.5% >> 5400.38: extrarefs_bitmap receive-pack main~10:main 32.43(20.88+11.75) 32.35(20.68+11.89) -0.2% >> 5400.40: extrarefs_bitmap receive-pack :main 7.21(3.58+3.63) 7.18(3.61+3.57) -0.4% > > We're doing less work so I'd expect to te be faster, but do these tests > really back that up? From eyeballing these I can't find a line where the > confidence intervals don't overlap, e.g. the +10% regresison is a > .10->.11 "regression" with a [+-] 0.02 (so within the error bars) etc, > ditto for the -50% improvement. > > Perhaps the error bars will reduce with a high GIT_PERF_REPEAT_COUNT, or > the re-arrangement for keeping things hotter in cache that I suggested > in 1/3. Urgh, nevermind. Just after I sent this I re-read t/perf/README. I'd somehow recalled that we'd emit error bars from it, but that's Elapsed(User + System), not Time(.. + errorbar) as I thought, nevermind. Still, numbers are such that I wonder if the differences are getting lost in some noise...
