[mkgmap-dev] splitter that generates problem list

Wed Nov 7 21:16:50 GMT 2012

Am 07.11.2012 19:19, schrieb Henning Scholland:
> Am 07.11.2012 19:06, schrieb WanMil:
>>> The profiling data shows that the CPU is most of the time
>>> busy with the pbf read and write routines, so I doubt that your disk
>>> is the bottleneck.
>>    From my experience profiling is a very time consuming (=> CPU
>> consuming) task. So could it also be that the disk is not the bottleneck
>> while you profile the application but it is the bottleneck while you
>> don't profile it? (It's just a guess...)
> If I believe in TaskManager, splitter takes 17% CPU-usage. This means
> one core is completly busy.
I have to correct this. splitter uses more cores while writing the tiles.
> HDD as bottleneck was only meant in general. I'm running splitter and
> mkgmap (and all input and output) on a SSD. But I think this is not
> typical. Maybe it would increase performance, if max-area keep smaller
> and splitter runs multiple times. E.g. I run two splitter with
> max-area=512. Will try this.
I tried it and it wasn't better. It tooks 10 min longer (1:30 to 1:20 
h). Reducing max-area from 1024 to 512 doesn't save enough RAM, that two 
splitter instances have enough RAM. So I think it would be more 
effective to use threading also in analysing the polygons e.g one threat 
for reading pbf and another one for checking the object, don't know if 
this is possible.

Henning