International Business Machines Corporation

Minoru Kida

Nobuyoshi Tanaka

Hiroshi Dohji

Yasuyuki Ohki

Hironori Makimura

To provide a method and the like for testing a main memory in a multi processor system, which is capable of reducing a test execution time and accordingly a start-up time as compared with the case where a single processor is used for the test. The present invention provides a method for testing a main memory (MM) in a multi processor system (MPS) including a main processor (MP) and multiple sub processors (SP) each having a DMA transfer mechanism and a local store (LS). The method and the like including: MP allocating a partial memory region (PMA) in MM to each SP; MP requesting each SP to test the allocated PMA; each SP filling LS thereof with initial data in response to receiving the request; each SP transferring the data stored in LS thereof to PMA by using a DMA transfer; each SP transferring the data stored in PMA to LS thereof by a DMA transfer; and SP testing the data in LS; and MP judging a test result on MM by putting together the tests results in response to the completion of all the tests by respective SP.

Memory testing using multiple processor unit, DMA, and SIMD instruction

According to the present invention, it is possible to reduce the fan noise taking the human sense into consideration. Specifically, it is possible to ergonomically mitigate the discomfort due to the short-term variation of the working rate of the CPU by increasing the rotational frequency gradually and by decreasing the rotational frequency with the temperature fall taking the human sense of noise into account. The present invention reduces noise produced by a cooling fan by controlling the fan rotation to a minimum rotational frequency in accordance with the specification and performance of the heat source. Additionally, an embodiment of the present invention controls a cooling fan to a minimum allowable rotational frequency within a rated temperature range of the object to be cooled, thereby controlling the internal temperature of a computer system in such a way to minimize noise generation.

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Kanagawa-ken, Japan

Minoru Kida