On Fri, 09 Jan, at 01:58:29PM, Peter Zijlstra wrote: > > Right, but we'll also consider RMIDs with less than this as fit for > reuse. So we'll re-use RMIDs that are effectively full. > > Our aim is to acquire an 'empty' RMID, not give up and start reusing > full ones just because, right?
The threshold was designed so that we're guaranteed to make forward progress. If we're bumping the threshold, *none* of the RMIDs on the limbo list have an occupancy value less than the threshold value. At that point, we've got two options, 1) Increase the threshold value and further skew the results 2) Steal another RMID and pray it's below the threshold We actually do both currently. Now, one thing that we don't do is traverse the entire list of active RMIDs looking for the least value one, because it's pretty expensive to do that as it incurs lots of MSR reads and writes. -- Matt Fleming, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
