On Fri, Feb 08, 2008 at 05:27:03PM -0800, Christoph Lameter wrote: > Pages will still be on the LRU and cycle through rmap again and again. > If page migration is used on those pages then the code may make repeated > attempt to migrate the page thinking that the page count must at some > point drop. > > I do not think that the page count was intended to be used to pin pages > permanently. If we had a marker on such pages then we could take them off > the LRU and not try to migrate them.
The VM shouldn't break if try_to_unmap doesn't actually make the page freeable for whatever reason. Permanent pins shouldn't happen anyway, so defining an ad-hoc API for that doesn't sound too appealing. Not sure if old hardware deserves those special lru-size-reduction optimizations but it's not my call (certainly swapoff/mlock would get higher priority in that lru-size-reduction area). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/