Avoiding aborts due to associativity conflicts in a transactional environment

摘要

Embodiments relate to a transactional read footprint after a cache line eviction. An aspect includes executing one or more read instructions in an active transaction. A cross invalidate (XI) request for a target cache line is received, and it is determined if the target cache line is part of a congruence class in a local cache. It is further determined whether an extension flag associated with the congruence class is set. The extension flag is used to indicate that cache lines of the congruence class associated with the active transaction have been replaced based only on being least recently used and that the target cache line is not in the cache. Execution of the active transaction continues based on determining that the extension flag is not set. Execution of the active transaction is aborted based on determining that the extension flag is set.

主权项

1. A system for tracking a transactional read footprint after a cache line eviction, the system comprising:
a hardware processor comprising a transactional read footprint tracking circuit, the transactional read footprint tracking circuit configured to perform a method comprising: executing one or more read instructions in an active transaction, wherein a transaction effectively delays committing stores to memory until the active transaction successfully completes; receiving a cross invalidate (XI) request for a target cache line; determining that the target cache line is part of a congruence class in a local cache; determining whether an extension flag associated with the congruence class is set, the extension flag indicating that cache lines of the congruence class associated with the active transaction has been replaced based only on being least recently used, and the target cache line is not in the cache; based on the extension flag being not set, continuing execution of the active transaction; and based on the extension flag being set, aborting execution of the active transaction.