Created attachment 102420 [details]
Heap histograms before and after restart

For the past couple of months (?) I have found that the IDE gradually consumes more and more heap over time. Even though my max heap is 512Mb, which should be plenty, after a couple hours my consumed heap remains in the high 400's, and garbage collection occupies so much time that the IDE is unusable.

Attaching two (live) heap histograms, one before shutdown, one soon after restart with the same open projects and files (14 Maven projects and 23 NBM projects), with scanning complete. Obviously after restart I have not yet run external processes or used various IDE features, so it is to be expected that heap consumption is significantly lower. Yet there are some notable differences that should not obviously result from extended IDE usage; in particular, the old dump seems to have a lot of javac-related objects, and a lot of editor.lib.impl.MultiMark's.

Since this problem occurs pretty regularly for me these days, I can probably reproduce it and do more in-depth analysis. Directly examining "old" heap dumps in the Profiler (or jhat) is difficult, since they are so big they tend to overwhelm these tools, but if there is a very specific area to investigate (e.g. typical content of all those String's) I can probably do it. Are there any tools which take a large dump as input, and using bounded memory themselves, construct summaries of interesting objects occurring in large numbers like String, File, Map<String,?>, etc.?