Re: Why active list and inactive list?

[Christoph Lameter]

On Tue, 23 Jan 2007, Balbir Singh wrote:

> When you unmap or map, you need to touch the pte entries and know the
> pages involved, so shouldn't be equivalent to a list_del and list_add
> for each page impacted by the map/unmap operation?

When you unmap and map you must currently get exclusive access to the 
cachelines of the pte and the cacheline of the page struct. If we use a 
list_move on page->lru then we have would have to update pointers in up 
to 4 other page structs. Thus we need exclusive access to 4 additional 
cachelines. This triples the number of cachelines touched. Instead of 2 
cachelines we need 6.


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/