Are you confusing physical memory with address space?
There's no good reason for the managed heap to be anywhere near any of the native heaps in address space, on 64-bit platforms.
And the CLR's GC should actively allocate slabs well away from any native heap (trivial to do - reserve (not commit, reserve) a big contiguous chunk of address space), simply because it relies on third party code which will itself be allocating native memory; everything from GUI code to native DB drivers and their caches, quite independent of unsafe code doing manual allocation.
In the absence of a GC-aware virtual memory manager, GC-immovable memory has little relevance to paging.
(Of course, GC.Add/RemoveMemoryPressure should be called if you're doing native allocation from .net.)
There's no good reason for the managed heap to be anywhere near any of the native heaps in address space, on 64-bit platforms.
And the CLR's GC should actively allocate slabs well away from any native heap (trivial to do - reserve (not commit, reserve) a big contiguous chunk of address space), simply because it relies on third party code which will itself be allocating native memory; everything from GUI code to native DB drivers and their caches, quite independent of unsafe code doing manual allocation.
In the absence of a GC-aware virtual memory manager, GC-immovable memory has little relevance to paging.
(Of course, GC.Add/RemoveMemoryPressure should be called if you're doing native allocation from .net.)