[erlang-questions] beam.smp startup time regression

Björn-Egil Dahlberg <>
Fri Apr 4 14:59:25 CEST 2014


Most the time you measure has to do with file handling and loading modules.
I believe there is around 75 files (modules) that loads during startup.

You can strip the system if you want faster load time and perhaps 
archives would be another choice.

Also, async threads delivers some overhead, you can disable them (don't 
do it).

// Björn-Egil

On 2014-04-04 14:45, Tuncer Ayaz wrote:
> The recent HiPE and half-word-emu threads made me recheck a subjective
> impression I had about the steady increase of beam.smp startup time
> over several OTP releases.
>
> I used to build with --enable-native-libs, but the already not quick
> enough startup time of beam.smp got even longer, so in default nodes I
> use neither HiPE nor --enable-native-libs.
>
> Unscientifically and quickly measured average time to run
> $ time erl -eval 'halt(0).'
> with different Erlang/OTP releases (no native-libs at all):
>
> # R13B03
> real    0m0.261s # min 0.254 max 0.264
> user    0m0.143s
> sys     0m0.020s
>
> # R14B04
> real    0m0.293s # min 0.289 max 0.301
> user    0m0.167s
> sys     0m0.033s
>
> # R15B03-1
> real    0m0.318s # min 0.315 max 0.323
> user    0m0.203s
> sys     0m0.002s
>
> # R16B03-1
> real    0m0.373s # min 0.354 max 0.381
> user    0m0.257s
> sys     0m0.053s
>
> To be precise, R16B03-1 is the only beam.smp with halfword-emu, but
> the last time I measured this some time back, R16 without halfword-emu
> on i386 was also considerably slower.
>
> I believe the R15 increase is due to Raimo's flushing fixes and that's
> the right thing to do, but it steadily increases with each release and
> especially so in R16.
>
> Personally, I think this is a regression and makes using escripts less
> fun than it used to be.
>
> A proper measurement would build beam.smp with the same configure
> flags and probably even use git-bisect to track down commits. I don't
> have time for this right now, but decreasing startup time could be a
> fun project :).
> _______________________________________________
> erlang-questions mailing list
> 
> http://erlang.org/mailman/listinfo/erlang-questions
>
>




More information about the erlang-questions mailing list