On Fri, Aug 9, 2019 at 2:26 PM Johannes Schindelin <Johannes.Schindelin@xxxxxx> wrote: > > FWIW I am very much in favor of this approach. FWIW this is (almost) exactly what I had in mind with my first reply, except I wanted to make setting of the global context be conditioned to having NED enabled to avoid possible performance issues in environments were NED is not even usable. in macOS (obviously testing without NED) the following is the output of (a hacked version) of p7801 for maint (against chromium's repository), with René's patch on top Test HEAD^ HEAD -------------------------------------------------------------------------------------- 7820.1: perl grep 'how.to' 0.51(0.35+1.11) 0.48(0.33+1.16) -5.9% 7820.2: perl grep '^how to' 0.47(0.33+1.08) 0.45(0.34+1.11) -4.3% 7820.3: perl grep '[how] to' 0.49(0.40+1.11) 0.53(0.41+1.13) +8.2% 7820.4: perl grep '(e.t[^ ]*|v.ry) rare' 68.72(68.77+1.14) 72.10(72.15+1.20) +4.9% 7820.5: perl grep 'm(ú|u)lt.b(æ|y)te' 0.48(0.35+1.12) 0.50(0.40+1.23) +4.2% and this is with my squashed[2] changed on top of that : Test HEAD^ HEAD -------------------------------------------------------------------------------------- 7820.1: perl grep 'how.to' 0.48(0.36+1.16) 0.46(0.33+1.09) -4.2% 7820.2: perl grep '^how to' 0.45(0.34+1.12) 0.42(0.29+0.99) -6.7% 7820.3: perl grep '[how] to' 0.48(0.40+1.13) 0.52(0.43+1.16) +8.3% 7820.4: perl grep '(e.t[^ ]*|v.ry) rare' 69.12(69.10+1.07) 69.19(69.19+1.18) +0.1% 7820.5: perl grep 'm(ú|u)lt.b(æ|y)te' 0.49(0.38+1.17) 0.46(0.35+1.13) -6.1% the degenerate case is not something we can't fix anyway, since it is likely a locking issue inside PCRE2 (I see at most 1 CPU doing work), and the numbers are noisy because of the other problems I mentioned before (hardcoded to 8 threads, running in a laptop with low number of cores), which is why testing for performance regressions in windows is strongly encouraged, regardless Carlo [1] https://public-inbox.org/git/CAPUEspgH1v1zo7smzQWCV4rX9pKVKLV84gDSfCPdT7LffQxUWw@xxxxxxxxxxxxxx/ [2] https://public-inbox.org/git/20190810030315.7519-1-carenas@xxxxxxxxx/
