Can't use the same JVMPI min=max heap setting for JVMTI

Question

I have a DLL that serves as both PI and TI library. When using PI, I can specify -XmsNNNNm -XmxNNNNm but the same setting would not work when switching to TI. I must lower the heap setting by as much as 725M on a Windows box. On UNIX, I only need to lower it by 5-20M depending on machines. It does not matter when JVM 1.5 or 1.6 is used.
I do specify a base address for the Windows library.
Any help is appreciated.

Answer 1

bspike, are you sure your DLL is actually getting loaded at the rebase address? The rebase address is just a hint; if the address space is occupied at DLL load time (maybe by another DLL), Windows will load your DLL somewhere else. I'm wondering if this could be happening in your case, and the DLL is getting loaded in a bad spot. I usually use vadump.exe (http://www.microsoft.com/downloads/details.aspx?FamilyID=3fe0961b-ea72-40eb-a052-f68bac5a8ec1&displaylang=en to print, for a particular process, where the DLLs actually get loaded:
c:\hotspot>vadump -sv -p 3624
Symbols loaded: 00400000 : 00AF6000 FIREFOX.EXE
Symbols loaded: 7C900000 : 7C9B0000 ntdll.dll
Symbols loaded: 7C800000 : 7C8F5000 kernel32.dll
Symbols loaded: 600B0000 : 60119000 js3250.dll
Symbols loaded: 60170000 : 60197000 nspr4.dll
....etc.
Even if it's not the specific problem I mentioned above, vadump might help diagnose the reason a large contiguous region isn't available.
Steve