PPTX File Conversion Service causes Sustained CPU Spike

top - 23:26:08 up 1:21, 5 users, load average: 2.73, 1.69, 1.54 
Threads: 127 total, 2 running, 125 sleeping, 0 stopped, 0 zombie 
%Cpu(s): 20.6 us, 3.3 sy, 3.7 ni, 67.4 id, 5.0 wa, 0.0 hi, 0.0 si, 0.0 
KiB Mem: 16308168 total, 16031976 used, 276192 free, 142336 buffers 
KiB Swap: 16649212 total, 320 used, 16648892 free. 3376844 cached Mem 

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 
30249 doomcha+ 20 0 5146408 1.801g 46464 R 99.9 11.6 0:11.08 java 
5758 doomcha+ 20 0 5146408 1.801g 46464 R 98.7 11.6 0:11.41 java 
5765 doomcha+ 20 0 5146408 1.801g 46464 S 13.2 11.6 1:40.21 java

 "conversion-thread-0-internal" #253 daemon prio=1 os_prio=0 tid=0x00007fc6dda7f800 nid=0x7629 runnable [0x00007fc6bd57e000] java.lang.Thread.State: RUNNABLE at sun.java2d.loops.FillPath.FillPath(Native Method) at sun.java2d.pipe.LoopPipe.fill(LoopPipe.java:308) at sun.java2d.pipe.PixelToParallelogramConverter.fill(PixelToParallelogramConverter.java:164) at sun.java2d.SunGraphics2D.fill(SunGraphics2D.java:2527) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.ar.do(Unknown Source) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.ar.if(Unknown Source) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.ar.do(Unknown Source) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.ar.do(Unknown Source) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.pf4dd765c.ar.do(Unknown Source) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.pf4dd765c.ar.do(Unknown Source) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.pf4dd765c.ar.do(Unknown Source) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.pf4dd765c.ar.double(Unknown Source) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.pf4dd765c.ar.do(Unknown Source) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.c.getTransparency(Unknown Source) at sun.java2d.SunGraphics2D.setPaint(SunGraphics2D.java:1007) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.ar.do(Unknown Source) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.ar.if(Unknown Source) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.ar.do(Unknown Source) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.ar.do(Unknown Source) at com.aspose.slides.ms.core.System.Drawing.pf4dd765c.pbdb106a0.pa2137a2a.pa2137a2a.p7cce53cf.m.do(Unknown Source) at com.aspose.slides.ms.core.System.Drawing.pf4dd765c.pbdb106a0.pa2137a2a.pa2137a2a.p7cce53cf.m.do(Unknown Source) at com.aspose.slides.ms.core.System.Drawing.pf4dd765c.pbdb106a0.pa2137a2a.pa2137a2a.pbdb106a0.c.do(Unknown Source) at com.aspose.slides.ms.core.System.Drawing.pf4dd765c.pbdb106a0.c.do(Unknown Source) at com.aspose.slides.ms.core.System.Drawing.pf4dd765c.pbdb106a0.a.do(Unknown Source) at com.aspose.slides.ms.core.System.Drawing.pf4dd765c.pbdb106a0.c.do(Unknown Source) at com.aspose.slides.ms.core.System.Drawing.pf4dd765c.pbdb106a0.c.void(Unknown Source) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.pa2137a2a.ak.super(Unknown Source) at com.aspose.slides.ms.pbdb106a0.p6a2feef8.pa2137a2a.ak.<init>(Unknown Source) at com.aspose.slides.p883e881b.am.do(Unknown Source) at com.aspose.slides.ImageCollection.do(Unknown Source) at com.aspose.slides.axd.int(Unknown Source) at com.aspose.slides.axd.do(Unknown Source) at com.aspose.slides.axe.if(Unknown Source) at com.aspose.slides.axe.do(Unknown Source) at com.aspose.slides.Presentation.byte(Unknown Source) at com.aspose.slides.Presentation.new(Unknown Source) at com.aspose.slides.Presentation.int(Unknown Source) at com.aspose.slides.Presentation.<init>(Unknown Source) at com.aspose.slides.Presentation.<init>(Unknown Source) at com.atlassian.plugins.conversion.convert.image.SlidesConverter.loadPresentation(SlidesConverter.java:137) at com.atlassian.plugins.conversion.convert.image.SlidesConverter.generateThumbnailDirect(SlidesConverter.java:105) at com.atlassian.confluence.plugins.conversion.impl.runnable.JVMConversionRunnable.doWork(JVMConversionRunnable.java:69) at com.atlassian.confluence.plugins.conversion.impl.runnable.ConversionRunnable.run(ConversionRunnable.java:38) at com.atlassian.confluence.plugins.conversion.impl.runnable.JVMConversionRunnable.run(JVMConversionRunnable.java:17) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745)