We propose GPUSched, a foreground graphics aware preemptive scheduling framework for concurrent DNN inference and seamless graphics rendering on mobile GPUs. Given that existing GPU scheduling methods relying on offline slicing are inadequate for dynamic graphics workloads, GPUSched is driven by two key components: (i) Render-State Detection via GPUPing, which leverages lightweight probing of GPU queue latency to accurately identify foreground rendering operations and (ii) Adaptive Operator Chunking, which dynamically fits DNN model chunk sizes within GPU idle times in a GPU frequency-aware manner. By combining these mechanisms GPUSched, coordinates DNN inference with graphics rendering in real time, preventing deadline violations while maximizing GPU utilization. Experiments on two commodity mobile devices show that GPUSched consistently outperforms baseline schedulers, achieving lower deadline miss rates while sustaining high rendering quality even under demanding graphics workload.