Information processing apparatus
The information processing apparatus is provided with a plurality of arithmetic devices, a memory unit shared by the plurality of arithmetic devices, and a cache device. The cache device divides the memory space of the memory unit into a plurality of regions, and includes a plurality of caches in the same hierarchy, each of which is associated with a respective one of the plurality of regions. Each cache includes a cache core configured to exclusively store data from a respective one of the plurality of regions.
1. An information processing apparatus comprising:
a plurality of arithmetic devices;
a memory unit shared by the plurality of arithmetic devices; and
a cache device,
the cache device being configured to divide the memory space of the memory unit into a plurality of regions and including a plurality of caches in the same hierarchy, each of which is associated with a respective one of the plurality of regions,
each cache including a cache core configured to exclusively store data from a respective one of the plurality of regions,
wherein a coherence mechanism is not provided for the plurality of caches.
2. The information processing apparatus according to claim 1 , wherein each of the arithmetic devices is configured to selectively connect to a cache associated with a region which is required to be accessed by the arithmetic device among the plurality of regions of the memory unit.
3. The information processing apparatus according to claim 1 , wherein each cache further includes:
a first memory section configured to store a position in the cache core that is lastly accessed by each of the arithmetic devices; and
a replacement target selecting section configured to exclude the position in the cache core stored in the first memory section from the replacement target.
4. The information processing apparatus according to claim 3 , wherein the replacement target selecting section is configured to add a position that is lastly accessed by the arithmetic device which caused a cache mistake among the positions in the cache core stored in the first memory section to the replacement target.
5. The information processing apparatus according to claim 3 , wherein
each cache further includes a second memory section configured to store whether or not data is updated and whether the data is referenced after the updating at each position being a unit for replacement in the cache core, and
the replacement target selecting section is configured to exclude data that is not referenced again after the updating from the replacement target.
6. The information processing apparatus according to claim 1 , wherein the cache device further includes at least one cache in a lower level hierarchy than the plurality of caches.
7. An information processing apparatus comprising:
a plurality of arithmetic devices;
a memory unit shared by the plurality of arithmetic devices; and
a cache device,
the cache device being configured to divide the memory space of the memory unit into a plurality of regions and including a plurality of caches in the same hierarchy, each of which is associated with a respective one of the plurality of regions,
each cache including a cache core configured to exclusively store data from a respective one of the plurality of regions
wherein each cache further includes:
a first memory section configured to store a position in the cache core that is lastly accessed by each of the arithmetic devices;
a replacement target selecting section configured to exclude the position in the cache core stored in the first memory section from the replacement target; and
a second memory section configured to store whether or not data is updated and whether the data is referenced after the updating at each position being a unit for replacement in the cache core, and wherein the replacement target selecting section is configured to exclude data that is not referenced again after the updating from the replacement target.
8. An information processing apparatus comprising:
a plurality of arithmetic devices;
a memory unit shared by the plurality of arithmetic devices; and
a cache device including a plurality of caches,
each cache comprising:
a cache core constituted by a set associative cache having a plurality of ways; and
a replacement target selecting section configured to determine, from the plurality of ways, a way to be preferentially replaced when a cache mistake occurs, based on preset information indicating a correspondence relationship between a priority and a state of access to a cache line from any of the plurality of arithmetic devices.
9. The information processing apparatus according to claim 8 , wherein
a memory space of the memory unit is divided into a plurality of regions,
the plurality of caches are in the same hierarchy,
each of the plurality of caches is associated with a respective one of the plurality of regions, and
the cache core of each cache is configured to exclusively store data from a respective one of the plurality of regions.
10. The information processing apparatus according to claim 9 , wherein
each cache further includes a first memory section configured to store a position in the cache core that is lastly accessed by each of the arithmetic devices,
the replacement target selecting section is configured to exclude the position in the cache core stored in the first memory section from the replacement target.
11. The information processing apparatus according to claim 10 , wherein the replacement target selecting section is configured to add a position that is lastly accessed by the arithmetic device which caused a cache mistake among the positions in the cache core stored in the first memory section to the replacement target.
12. The information processing apparatus according to claim 10 , wherein
each cache further includes a second memory section configured to store whether or not data is updated and whether the data is referenced after the updating at each position being a unit for replacement in the cache core, and
the replacement target selecting section is configured to exclude data that is not referenced again after the updating from the replacement target.
13. The information processing apparatus according to claim 9 , wherein a coherence mechanism is not provided for the plurality of caches.
14. The information processing apparatus according to claim 9 , wherein each of the arithmetic devices is configured to selectively connect to a cache associated with a region which is required to be accessed by the arithmetic device among the plurality of regions of the memory unit.
15. The information processing apparatus according to claim 8 , wherein the cache device further includes at least one cache in a lower level hierarchy than the plurality of caches.