FORWARD PROGRESS ON RETRIED SNOOP HITS

摘要

The present invention relates to re-execute the snoop forward progress performing the method and system of the heat upon. When the apparatus for snooping the system bus of a multiprocessor system detects an operation requesting the data present in the local memory in a predetermined consistency condition that requires that data is provided from the device, the device attempts to intervene. When disturbed by a second device that the intervention of re claims, the apparatus sets the flag to provide historical information about the failed intervention. In the same cache if a subsequent snoop hit during device for a location which is again assert intervention and rerun the snooping operation again, the device is required cache entries towards the end coherency state is expected to be corresponding to the result of the initial operation requiring the cache entry the start of the operation to correct the inconsistent state. When requesting cache entry including the modified data existing in the local memory of the device, the operation may include a push operation to record the request cache entry to the system memory. This push operation may be snooping by another device from the system bus to update the local memory of the other device. If you are not a modification request cache entry states, including the data in a predetermined consistent state, the operation can simply be included to modify the coherency state to share or disabled. When the initial operation is a read operation, the state transition of the cache proceeds in accordance with a sequence that ends in a shared state. If it contains an indication of the intent to modify the request cache entry as read in the initial operation intended to be modified, consistent state transition proceeds in accordance with a sequence that ends in an invalid state. May be used to determine the time when a single failure involved (single failed intervention) flag instead of the reflection counter is sustainable lock the threshold number failed intervention indicating that generation of the excess.