[mkgmap-dev] max-jobs patch

Wed Feb 7 21:28:08 GMT 2018

I don't know, if Nordrhein-Westfalen is that kind of large tiles you 
meant. Splitter ended up with 43 files and i tried to make mapsource 
maps with and without --max-jobs option and mkgmap r4000. My computer 
does the job with 43 files about 12minutes faster than without this 
option. My laptop is a core i5 with 8Gb of memory. The command i use is 
like this line :

java -Xmx7500m -XX:-UseGCOverheadLimit -ea -jar 
-Dlog.config=logging.properties 
C:\PROGRA~2\KartenTools\mkgmap\mkgmap.jar 
--location-autofill=is_in,nearest --mapname=70060001 --family-id=7006 
.\styles\mystyle.txt --series-name="STYLE TEST" 
--family-name="OpenStreetmap" --country-name=STYLETEST 
--country-abbr=STY --area-name=STY --overview-mapname="overview" 
--latin1 --style-file=.\styles --style=myland --max-jobs --keep-going 
--check-roundabouts --drive-on=detect,right --output-dir=.\out\MYSTYLE 
--index --bounds=mybounds --route 
--name-tag-list=name,place_name,loc_name --housenumbers 
--x-split-name-index --add-pois-to-areas --precomp-sea=.\input\sea.zip  
--tdbfile --draw-priority=10 --gmapsupp -c .\data\MYSTYLE\template.args 
--description=MYSTYLE --remove-ovm-work-files=true

Hope this gave you some useful hints

Am 07.02.2018 um 20:06 schrieb Gerd Petermann:
> Hi Mike,
>
> I did not yet try it. My understanding is that the Garbage Collection will try hard
> to avoid an out of heap exception. In other words: A user might see better throughput
> with fewer parallel jobs. What are your experiences? Did you try with
> large maps, say > 40 large tiles ?
>
> Gerd
>
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Mike Baggaley <mike at tvage.co.uk>
> Gesendet: Mittwoch, 7. Februar 2018 01:58
> An: 'Development list for mkgmap'
> Betreff: Re: [mkgmap-dev] max-jobs patch
>
> Hi Gerd, please find attached v2 of the max-jobs patch.
>
> This version additionally catches out of heap memory exceptions and displays
> a message suggesting either the use of the Java -Xmx option to increase the
> available heap memory or the mkgmap --max-jobs option with a smaller value
> to reduce the memory requirement (the latter is suggested only if using more
> than one thread).
>
> How does that seem?
> Regards,
> Mike
>
> -----Original Message-----
> From: Gerd Petermann [mailto:gpetermann_muenchen at hotmail.com]
> Sent: 05 February 2018 07:28
> To: Mike Baggaley <mike at tvage.co.uk>; 'Development list for mkgmap'
> <mkgmap-dev at lists.mkgmap.org.uk>
> Subject: Re: [mkgmap-dev] max-jobs patch
>
> Hi Mike,
>
> thought about this again. Maybe this change is too simple. With multiple
> jobs one also
> needs more heap (-Xmx JRE option). If you create rather large tiles with
> splitter (max-nodes=1600000)
> you need 0.5 - 1 GB for each job. Not sure what happens when a user creates
> a map with
> 10 tiles on an 8-core machine without any -Xmx option.
>
> I fear this will result in OutOfMemory exception, so better check the
> available heap as well.
>
> Gerd
>
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Mike
> Baggaley <mike at tvage.co.uk>
> Gesendet: Sonntag, 4. Februar 2018 15:14
> An: 'Development list for mkgmap'
> Betreff: [mkgmap-dev] max-jobs patch
>
> Hi Gerd,
>
> Please find attached a patch that amends the default behaviour if the
> --max-jobs option is not specified, to using a value equal to the number of
> CPU cores, as suggested in a previous post. The documentation is also
> amended to reflect the change. This halves the execution time of mkgmap for
> building a map of Staffordshire on my 8-core PC when --max-jobs is not
> specified (I didn't know about this option previously and was unaware the
> performance could have been improved).
>
> Cheers,
> Mike
>
> _______________________________________________
> mkgmap-dev mailing list
> mkgmap-dev at lists.mkgmap.org.uk
> http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
>
-- 

  Mit freundlichen Grüßen

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