On Mon, 20 Aug 2012, Mel Gorman wrote:

> Kosaki's original patch for this problem was to allocate an sp node and policy
> within shared_policy_replace and initialise it when the lock is reacquired. I
> was not keen on this approach because it partially duplicates sp_alloc(). As
> the paths were sp->lock is taken are not that performance critical this
> patch converts sp->lock to sp->mutex so it can sleep when calling sp_alloc().

Reviewed-by: Christoph Lameter <cl@linux.com>