Conclusion: Your changes seem to have made my PBO-related worry evaporate. Thank you.
About the luigi_maroni's ensureUnpackPBOdisabled() problem, well, I can't really comment on them as I've not put my eyes on them at all.
This is the code I used for testing:
http://paste.servut.us/1itu (Didn't dare to paste using bbCode's code-block as I don't know how awfully long the post would have been made. Though for future references to the code it would probably be best if it was included in this post.
So me. I forgot part of the code. The GLTextureLoader:
http://paste.servut.us/yed8 Yay.
LWJGL v2.1.0, actually using the texture (average for five runs of the test):Loading image started
Loading image finished, took 509ms
Initializing texture started
Initializing texture finished, took 6ms
Map PBO started
Map PBO finished, took 0ms
Image conversion to BGR(A)8 format started
Image conversion to BGR(A)8 format finished, took 131ms
Unmap PBO started
Unmap PBO finished, took 0ms
Initiate image upload started
Initiate image upload finished, took 3ms
Display update started
Display update finished, took 81ms
Display update started
Display update finished, took 9ms
Display update started
Display update finished, took 0ms
Display update started
Display update finished, took 0ms
LWJGL v2.1.0, without actually using the texture (average for five runs of the test): (Only differences)
Loading image finished, took 643ms
Initializing texture finished, took 3ms
Image conversion to BGR(A)8 format finished, took 137ms
Display update started
Display update finished, took 81ms
Display update started
Display update finished, took 6ms
LWJGL v2.2.0, actually using the texture (average for five runs of the test): (Only differences)
Loading image finished, took 647ms
Initializing texture finished, took 0ms
Image conversion to BGR(A)8 format finished, took 140ms
Initiate image upload finished, took 0ms
Display update started
Display update finished, took 3ms
Display update started
Display update finished, took 84ms
LWJGL v2.2.0, without actually using the texture (average for five runs of the test): (Only differences)
Loading image finished, took 653ms
Initializing texture finished, took 0ms
Map PBO finished, took 3ms
Image conversion to BGR(A)8 format finished, took 131ms
Initiate image upload finished, took 0ms
Display update started
Display update finished, took 0ms
Display update started
Display update finished, took 90ms