Controlling access to at least one memory location by a transaction is provided in a multi-processor transactional execution environment. Included is: tracking execution progress of a transaction, the execution progress being a metric of work performed for the transaction which includes at least one of instructions processed or cycles elapsed; based on encountering a conflict with another process for a memory location, comparing execution process of the transaction and execution progress of the other process; and deciding whether to continue the transaction based on the comparing. For instance, based on the execution progress of the transaction being greater than the execution progress of the other process, the transaction is continued, and based on the execution progress of the transaction being less that the execution progress of the other process, then the transaction is aborted.