no swap

at>      mmap( 1Tb file ) into 64bit address space
at>      use part X of the file
at>      tell OS that part X of file is no longer needed

shap> Yes
shap> also need tell OS that I am about to need part Y of file" for load-ahead

shap> now consider what happens if you are mutating that stream on the way
shap> through (which is common in audio applications). You are telling the OS
shap> that part X can be removed from memory, but this is not the same as
shap> saying that it is no longer needed.

Sorry.. difficult to understand... could you plz explain a bit more?
Do we want to save page back to disk? Modify original stream file?
Are we writing another file?

shap> Now if we want to pursue Andy's proposal further, we will next propose
shap> that this should be handled by a mapping of a temporary file

So what's our sound processing app doing?

Anton