A computer system comprises a system memory, a first active device
configured to access data stored in the system memory, and a second
active device configured to access data stored in said system memory. The
first active device is configured to generate a read-to-share transaction
corresponding to a load operation. In response to receiving an
invalidating transaction subsequent to receiving the read-to-share
transaction, the first active device selectively allows the load
operation to complete depending upon an indication of whether the load
operation is a critical load. In one embodiment, an active device
comprises a processing unit and an interface controller coupled to
receive a load request corresponding to a load operation initiated by
said processing unit.