Information processing system and a system controller
AssigneeFujitsu Limited
InventorsYuuji KONNO, Hiroshi MURAKAMI
Life of this patent
Estimating the term…
Abstract
In a system including a plurality of CPU units having a cache memory of different capacity each other and a system controller that connects to the plurality of CPUs and controls cache synchronization, the system controller includes a cache synchronization unit which monitors an address contention between a preceding request and a subsequent request and a setting unit which sets different monitoring range of the contention between the preceding request and the subsequent request for each capacity of the cache memory in each of the CPU units.
Claims18
Information processing system comprising:
- a first CPU unit having a first CPU and a first cache memory that stores cache tag information and cache data;
- a second CPU unit having a second CPU and a second cache memory that stores cache tag information and cache data and has a different capacity from a capacity of the first cache memory;
- and
- a system controller that is connected to the first CPU unit and the second CPU unit and searches a third cache memory that stores a copy of the cache tag information in the first cache memory and a fourth cache memory that stores a copy of the cache tag information in the second cache memory according to a request to the first cache memory and the second cache memory from the first CPU unit and the second CPU unit,
- wherein the system controller comprising:
- a cache synchronization unit that monitors whether or not preceding request and subsequent request require same cache address by monitoring range of busy that is set and make a retry of the subsequent request that requires the same cache address as the preceding request to a CPU that has required when receiving the subsequent request before completing update of the copy of the cache tag information by the preceding request;
- and
- a setting unit that sets different monitoring ranges of the busy between the third cache tag memory and the fourth cache tag memory to the cache synchronization unit.
A system controller that is connected to a first CPU unit having a first CPU and a first cache memory that stores cache tag information and cache data and a second CPU unit having a second CPU and a second cache memory that stores cache tag information and cache data and has a different capacity from the capacity of the first cache memory, the system controller comprises:
- a cache tag search unit that searches a third cache memory that stores a copy of the cache tag information in the first cache memory and a fourth cache memory that stores a copy of the cache tag information in the second cache memory according to a request to the first cache memory and the second cache memory from the first CPU unit and the second CPU unit;
- a cache synchronization unit that monitors whether or not preceding request and subsequent request require same cache address by monitoring range of busy that is set and make a retry of the subsequent request that requires the same cache address as the preceding request to a CPU that has required when receiving the subsequent request before completing update of the copy of the cache tag information by the preceding request;
- and
- a setting unit that sets different monitoring ranges of the busy between the third cache tag memory and the fourth cache tag memory to the cache synchronization unit.
Dependencies are inferred from the claim text.