Abstract: A computer system includes a processor core and a memory system in signal communication with the processor core. The memory system includes a first cache and a second cache. The first cache is arranged at a first level of a hierarchy in the memory system and is configured to store a plurality of first-cache entries. The second cache is arranged at a second level of the hierarchy that is lower than the first level, and stores a plurality of second-cache entries. The first cache maintains a directory that contains information for each of the first-cache entries. The second cache maintains a shadow pointer directory (SPD) that includes one or more SPD entries that maps each of the first-cache entries to a corresponding second cache entry at a lower-level cache location.

Abstract: The present invention provides a bulk liquid container (1) for the storage and distribution of water to a community as drinking water. The container comprises a container housing for holding water, the housing having a substantially capsular form; an output valve (2) arranged to release water from the container; a water filter (101) arranged to filter water passing from the internal volume of the container out of the container through the output valve, the filter comprising one or more membranes and comprising a plurality of sub-groups of hollow fibres (61) which are effective to pass water in preference to air under the influence of a pressure differential; and a pump for raising the internal pressure of the container. The invention further provides a filter (101) for use in the container.