> 
> > Mmap() was a nonstarter; the app didnt fit in physical memory anyway,
> > nevermind the linear once-only pass.
> 
> But is there a reason you couldn't mmap each megabyte and MADV_WILLNEED
> the pages before processing and unmapping the previous chunk?

What I had in mind....
> 
> Or does MADV_WILLNEED not trigger pageins?
> 
> > I didnt dare try an ffs with 1meg blocks and 128k fragments and
> > 2-block readahead: would that have worked?
> 
> Ooo.  You're twisted.  I love it.

How about using a separate thread to fault in the required pages
(in advance of the main process).  Maybe need to map shared and
use a child process...

    David