Fujitsu Corporation

Kotaro Kuwahara

Takashi Suzuki

Yuki Yoshida

A processing device includes a processor configured to output a memory access instruction issued by a process executed on a virtual machine and a virtual address targeted by the memory access instruction. The processor is configured to perform first translation of translating the virtual address into a real address of a virtual memory. The processor is configured to perform second translation of translating the real address into a physical address of a physical memory. The processor is configured to determine, based on the memory access instruction and an access permission attribute of the real address, whether an access permission violation occurs. The processor is configured to perform, upon determining that an access permission violation occurs, retranslation of translating the virtual address into the real address. The processor is configured to record the virtual address and the real address obtained by the retranslation in a log area of a memory.

Processing device and method for controlling processing device

An arithmetic processing device includes: first prediction units which output branch prediction information of a fetched conditional branch instruction based on past branch history information of conditional branch instructions; a second prediction unit which stores a branch taken consecutive number of times and a branch not-taken consecutive number of times to a pattern information storage unit, and outputs branch prediction information of a fetched conditional branch instruction based on the past branch taken consecutive number of times or branch not-taken consecutive number of times stored; selecting units which selectively output the branch prediction information output from the first prediction units or the second prediction unit; and a selector which outputs a next instruction address of the conditional branch instruction or a branch target address of the conditional branch instruction to an instruction fetch unit in accordance with the branch prediction information output by the selecting units.

Growing community of inventors

Suginami, Japan

Kotaro Kuwahara