[mkgmap-dev] Mkgmap appears to hang on some split files

Mon Sep 28 14:16:36 BST 2009

Hi Lambertus,

What you have attached is a crash dump from the JVM, not a stack dump of 
the (running) Java application. How are you getting that file? If it's being 
generated as the result of you killing the process, then it's not useful. 
You need to instead try and get a stack dump output by following Steve's 
directions. Did you try pressing CTRL-\ in the hung terminal window, or running 
"kill -QUIT <pid>", or "kill -3 <pid>", or "jstack <pid>"? Doing so should 
output information about the current state of mkgmap (what threads are running 
and what they're doing, etc) which should help diagnose the problem.

Chris

L> It happened again, this time straight from the commandline while
L> trying to render the three failed tiles at once by providing r2228
L> the *.osm.gz parameter... Stack dump is attached.
L> 
L> r1067 finishes the same test normally (with errors). Then I tried
L> r2228 again a few times and it finishes normally (with errors) as
L> well.
L> 
L> Aaargh!
L> 
L> http://planetosm.oxilion.nl/~lambertus/73240155.osm.gz
L> http://planetosm.oxilion.nl/~lambertus/73240185.osm.gz
L> http://planetosm.oxilion.nl/~lambertus/73240240.osm.gz
L> 
L> Lambertus wrote:
L> 
>> Thanks for having a look at it Steve. Stackdumps are attached. OS =
>> Ubuntu linux 9.04 64bit. LANG variable = en_US.UTF-8. Java version =
>> 1.6.0_0, OpenJDK RE 6b14-1.4.1- at ubuntu11, OpenJDK 64bit server VM
>> 14.0-b88 mixed-mode.
>> 
>> I've tried r1067 from the commandline which fails to render the tiles
>> (out of memory) but exits 'normally' with a result code (which is
>> what I want). Then I tried version 1022 and 1028 from the commandline
>> and both finished quickly as well. So I'm starting to think it might
>> have something to do with the way PHP passthru() executes these
>> commands (I've written a PHP script that recursively splits and
>> renders tiles until all areas are rendered). But a quick Google
>> search did not bring up anything.
>> 
>> Steve Ratcliffe wrote:
>> 
>>> Hi Lambertus
>>> 
>>> On 28/09/09 08:36, Lambertus wrote:
>>> 
>>>> While trying to get a new world map update out the door I noticed
>>>> that Mkgmap sometimes hangs on an OSM data file produced with
>>>> Splitter. When this happens the CPU is at 100% constantly for hours
>>>> (e.g. all night) until I kill the process. The problem occurs in
>>>> r1222 and also r1228.
>>>> 
>>> I ran the command line you gave with 1222 and 1228 on both the files
>>> and it completed in about a minute.  So no hang for me, and I'm
>>> going to have to ask a few questions to have any idea.
>>> 
>>> Is there any version where it works without hanging for you?
>>> What OS was it running on?
>>> What is the LANG variable set to (if running on Linux)?
>>> Could you send a stack dump when it is stuck, since it completes
>>> after 1 minute for me, probably waiting five minutes is more than
>>> enough to know that it is stuck.
>>> 
>>> You can get a stack trace using typing ctrl-\
>>> or using kill -QUIT on linux and on windows ctrl-break is supposed
>>> to
>>> work but I wouldn't know.  Another way that works the same
>>> everywhere
>>> is to use jstack.  Use jps to get the process id of the running
>>> processes and call jstack with that id. jstack and jps come with JDK
>>> download of java from sun and probably other places too.
>>> Thanks
>>> 
>>> ..Steve