A Memory-Level Parallelism Aware Fetch Policy for SMT Processors

A thread executing on a simultaneous multithreading (SMT) processor that experiences a long-latency load will eventually stall while holding execution resources. Existing long-latency load aware SMT fetch policies limit the amount of resources allocated by a stalled thread by identifying long-latency loads and preventing the given thread from fetching more instructions -- and in some implementations, instructions beyond the long-latency load may even be flushed which frees allocated resources. This paper proposes an SMT fetch policy that takes into account the available memory-level parallelism (MLP) in a thread. The key idea proposed in this paper is that in case of an isolated long-latency load, i.e., there is no MLP, the thread should be prevented from allocating additional resources. However, in case multiple independent long-latency loads overlap, i.e., there is MLP, the thread should allocate as many resources as needed in order to fully expose the available MLP. The proposed ML...

• Type: Conference
• Year: 2007
• Where: HPCA
• Authors: Stijn Eyerman, Lieven Eeckhout
• Keywords: Computer Architecture, HPCA 2007, MLP-aware Fetch Policy, SMT Fetch Policies, SMT Fetch Policy