On 01/10/2014 01:10 PM, Johannes Weiner wrote: > Previously, page cache radix tree nodes were freed after reclaim > emptied out their page pointers. But now reclaim stores shadow > entries in their place, which are only reclaimed when the inodes > themselves are reclaimed. This is problematic for bigger files that > are still in use after they have a significant amount of their cache > reclaimed, without any of those pages actually refaulting. The shadow > entries will just sit there and waste memory. In the worst case, the > shadow entries will accumulate until the machine runs out of memory. > > To get this under control, the VM will track radix tree nodes > exclusively containing shadow entries on a per-NUMA node list. > Per-NUMA rather than global because we expect the radix tree nodes > themselves to be allocated node-locally and we want to reduce > cross-node references of otherwise independent cache workloads. A > simple shrinker will then reclaim these nodes on memory pressure. > Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> Reviewed-by: Rik van Riel <riel@xxxxxxxxxx> -- All rights reversed -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
