IMPLEMENTING PER-PROCESSOR MEMORY AREAS WITH NON-PREEMPTIBLE OPERATIONS USING VIRTUAL ALIASES

摘要

A computer system provides a mechanism for assuring a safe, non-preemptible access to a private data area (PRDA) belonging to a CPU. PRDA accesses generally include obtaining an address of a PRDA and performing operations on the PRDA using the obtained address. Safe, non-preemptible access to a PRDA generally ensures that a context accesses the PRDA of the CPU on which the context is executing, but not the PRDA of another CPU. While a context executes on a first CPU, the context obtains the address of the PRDA. After the context is migrated to a second CPU, the context performs one or more operations on the PRDA belonging to the second CPU using the address obtained while the context executed on the first CPU. In another embodiment, preemption and possible migration of a context from one CPU to another CPU is delayed while a context executes non-preemptible code.

主权项

1. A method for assuring safe access to a private data area (PRDA) belonging to a CPU, comprising:
while a context executes on a first CPU, performing an access to a PRDA, wherein an access of the PRDA includes obtaining an address of the PRDA and performing one or more operations on the PRDA using the obtained address, said obtaining the address occurring while the context executes on the first CPU; and after the context is migrated to and while the context executes on a second CPU, performing one or more operations on a PRDA using the obtained address, wherein any operation on a PRDA using the obtained address after the context is migrated to the second CPU is an access of a PRDA belonging to the second CPU.