一句话：提出解耦垂直同步 D-VSync，让帧提前渲染并延后显示，降低掉帧与延迟。
智能手机 OS 的渲染服务通常用垂直同步（VSync）协调屏幕显示与 UI，但高帧率大屏、复杂特效和物理动画带来更高掉帧与延迟。本文提出 D-VSync，将渲染执行与显示解耦：帧可在显示前提前若干 VSync 周期渲染，用常见短帧节省的算力为偶发长帧提供更大时间窗口。在 OpenHarmony、Android 真机及 15 个移动游戏模拟上，相较 VSync，D-VSync 平均减少掉帧 72.7%、可感知卡顿 72.3%、渲染延迟 31.1%，功耗仅增 0.13%-0.37%，并已集成到 HarmonyOS NEXT。
Rendering service, which typically orchestrates screen display and UI through Vertical Synchronization (VSync), is an indispensable system service for user experiences of smartphone OSes (e.g., Android, OpenHarmony, and iOS). The recent trend of large high-frame-rate screens, stunning visual effects, and physics-based animations has placed unprecedented pressure on the VSync-based rendering architecture, leading to higher frame drops and longer rendering latency. This paper proposes Decoupled Vertical Synchronization (D-VSync), which decouples execution and displaying in the rendering service. D-VSync allows frames to be rendered a number of VSync periods before being physically displayed on the screen. The key insight behind D-VSync to resolve the limitation of VSync is that, the decoupling enables sporadic long frames to utilize the computational power saved by common short frames, therefore providing a larger time window to tolerate workload fluctuations. Evaluation results of 75 common OS use cases and apps on OpenHarmony (Mate 40 Pro, Mate 60 Pro), 25 popular apps on Android (Google Pixel 5), and simulations of 15 mobile games show that compared to VSync, D-VSync on average reduces frame drops by 72.7%, user-perceptible stutters by 72.3%, and rendering latency by 31.1%, with only 0.13%-0.37% more power consumption. D-VSync has been integrated into HarmonyOS NEXT.
@inproceedings{WuDXXFZ025,
title = {D-VSync: Decoupled Rendering and Displaying for Smartphone Graphics},
author = {Yuanpei Wu and Dong Du and Chao Xu and Yubin Xia and Ming Fu and Binyu Zang and Haibo Chen},
booktitle = {ASPLOS},
year = {2025},
doi = {10.1145/3669940.3707235}
}