Method and apparatus for checkpointing to facilitate reliable execution

1. Field of the Invention One embodiment of the present invention provides a system that facilitates reliable execution in a computer system by periodically checkpointing write operations to a main memory of the computer system. The system operates by receiving a write operation directed to the main memory at a memory controller, wherein the write operation includes data to be written to the main memory and a write address specifying a location in the main memory into which the data is to be written. Next, the system looks up the write address in a checkpoint store coupled to the memory controller. If the write address is not associated with any entry in the checkpoint store, the system creates an entry for the write address in the checkpoint store, and writes the data to be written to the entry. The system then periodically performs a checkpointing operation, which transfers the data to be written from the checkpoint store to the write address in the main memory.