Another thing you can do - and which has helped me in the past quite a few times - is to just run JVisualVM, attach to Solr's Java process and enable the CPU sampler under the Sampler tab.
As you run indexing the methods that most time is spent on will appear near the top. -- Sent from: http://lucene.472066.n3.nabble.com/Solr-User-f472068.html
