Re: Stack & policy

[James Antill <james@and.org>]

> Hi 
> 
> Some time ago I posted a message about a kernel feature where the
> application can request the vma->vm_start of its stack virtual memory area
> in order to unmap part of the unused stack (esp - vma->vm_start).
> 
> Such a feature is very useful for an alternative programming technique.

 Have you seen jamie and chuck talking about madvise() flags ?
 Just doing madvise(cur_stack, MADV_DONTNEED, cur_stack - end_stack)[1]
after a function that uses alloca() or has a large auto should be
a pretty simple addition to gcc (although you might not want to put it
there).

 Those seem like a much better idea to me, as they can also be used in
pthreads (much as I hate pthreads) and other bits of memory that has
similar usage patterns.
 This would also be much more likely to work on other OSes.

[1] I think I have the API correct but I don't have access to it atm.

-- 
James Antill -- james@and.org
"If we can't keep this sort of thing out of the kernel, we might as well
pack it up and go run Solaris." -- Larry McVoy.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux.eu.org/Linux-MM/