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[mkgmap-dev] tile takes very long time to generate

From Bernhard Hiller bhil at gmx.de on Tue Mar 9 08:50:40 GMT 2021

Hi Karl,
some time ago, I stumbled upon a tile which took 2 hours(!) on my machine.
With the "--polygon-file" option, the time could be reduced to less than
100 s.
See the old message in the archive:
and the thread "Performance with large files":
Perhaps the trick helps in your case, too.
Kind regards,

Am 08.03.2021 um 06:53 schrieb 7770:
> Hi.
> I observe a situation that one of the very first tiles (often the first or the
> third) that mkgmap generates takes 20 - 30 minutes to generate, wheres the
> others take about 30 seconds each.
> The map data produced by splitter is a total of around 700 files with splitter
> option --max-nodes=1275000.
> sea and bouds are used for mkgmap.
> At first i thought i am running low on memory but changing to max-jobs=1
> (instead of the possible max of 2) did not make any change.
> Is mkgmap doing something specific in the beginning that can explain this long
> time generating one of the very first tiles?
> I can provide more details, let me know how i can best collect those details
> in case i need to set some parameters to have mkgmap to say more about what it
> is doing.
> Regards
> Karl

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