Re: locking question: do_mmap(), do_munmap()

Stephen C. Tweedie
1999-10-13T10:25:36Z

Hi,

On Mon, 11 Oct 1999 18:31:37 -0400 (EDT), Alexander Viro
<viro@math.psu.edu> said:

> And spinlock being released in the ->swapout() is outright ugly. OK, so
> we are adding to mm_struct a new semaphore (vma_sem) and getting it around
> the places where the list is modified + in the swapper (for scanning). In
> normal situation it will never give us contention - everyone except
> swapper uses it with mmap_sem already held. Are there any objections
> against it? If it's OK I'll go ahead and do it. Comments?

Looks OK as long as the swapper remains non-recursive and we never, ever
allocate memory outside the swapper with vma_sem held.

--Stephen