Re: page fault scalability patch V11 [0/7]: overview

Linus Torvalds
2004-11-20T01:58:25Z

On Fri, 19 Nov 2004, Christoph Lameter wrote:
>
> Note though that the mmap_sem is no protection. It is a read lock and may
> be held by multiple processes while incrementing and decrementing rss.
> This is likely reducing the number of collisions significantly but it wont
> be a guarantee like locking or atomic ops.

It is, though, if you hold it for a write.

The point being that you _can_ get an exact rss value if you want to.

Not that I really see any overwhelming evidence of anybody ever really
caring, but it's nice to know that you have the option.

Linus