WIC: Hiding Producer-Consumer Synchronization Delays with Warp-Level Interrupt-based GPU Communications

GPU communication plays a pivotal role in collaborative computation across multiple devices. Despite advancements in inter-device communication fabrics and architectures, synchronization still remains a significant challenge due to the manual coordination required between producers and consumers at the application level. In this work, we first reveal that traditional synchronization is a primary bottleneck in GPU communication, where consumers frequently poll for producer data availability. Specifically, early-started polling leads to the unnecessary occupation of computational resources. To address this issue, we propose Warp-level Interrupt-based Communication (WIC), a novel synchronization framework for GPU communication that introduces a fine-grained interruption mechanism at the warp level to replace repetitive polling. WIC preemptively stalls warps engaged in frequent polling and releases computational resources for other warps, thereby effectively overlapping producer-consumer synchronization with ongoing computations. Comprehensive experiments demonstrate that WIC significantly outperforms conventional polling methods by 1.13 × on average across various applications with diverse communication patterns.