--- title: EuroSys 2025 Digest venue: EuroSys year: 2025 date: '2025-03-30' tags: - operating-systems - distributed-systems - cloud - storage - memory - networking - llm-systems - security - hardware-software-co-design - serverless paper_count: 13 draft: false --- 13 papers selected. --- ### Empowering WebAssembly with Thin Kernel Interfaces *Arjun Ramesh, Tianshu Huang, Ben L. Titzer, Anthony Rowe 0001* **TL;DR** — A new OS interface design exposes thin, capability-based kernel primitives directly to WebAssembly modules, eliminating the POSIX translation layer. **Why notable** — WebAssembly is increasingly used beyond the browser as a portable, sandboxed compute substrate; this work shows that rethinking the system interface from scratch yields significantly lower overhead and better safety properties than layering Wasm on top of POSIX. [→ Read paper](https://doi.org/10.1145/3689031.3717470) --- ### Revealing the Unstable Foundations of eBPF-Based Kernel Extensions *Shawn Wanxiang Zhong, Jing Liu 0074, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau* **TL;DR** — A systematic study exposes how eBPF programs silently break across kernel versions due to undocumented and unstable kernel data structure dependencies. **Why notable** — From the Arpaci-Dusseau group, this paper delivers surprising and practically consequential findings: a large fraction of real-world eBPF programs are fragile across kernel versions, undermining the widely held assumption that eBPF is a safe and stable extension mechanism. [→ Read paper](https://doi.org/10.1145/3689031.3717497) --- ### Pegasus: Transparent and Unified Kernel-Bypass Networking for Fast Local and Remote Communication *Dinglan Peng, Congyu Liu, Tapti Palit, Anjo Vahldiek-Oberwagner *et al.** **TL;DR** — Pegasus provides a single kernel-bypass networking stack that transparently accelerates both intra-host (IPC) and inter-host communication without application changes. **Why notable** — Unifying local and remote fast paths is a long-standing challenge; Pegasus demonstrates that the same RDMA-style techniques can be applied to loopback traffic, yielding substantial latency reductions for microservice workloads with no API changes. [→ Read paper](https://doi.org/10.1145/3689031.3696083) --- ### Daredevil: Rescue Your Flash Storage from Inflexible Kernel Storage Stack *Junzhe Li, Ran Shu 0001, Jiayi Lin 0007, Qingyu Zhang 0005 *et al.** **TL;DR** — Daredevil bypasses the rigid Linux block layer to allow flash storage devices to express fine-grained I/O semantics directly to applications. **Why notable** — The Linux storage stack was designed for spinning disks and consistently imposes unnecessary overhead on modern NVMe SSDs; Daredevil demonstrates that rethinking the kernel/device interface boundary unlocks significant throughput and latency gains that the existing stack structurally prevents. [→ Read paper](https://doi.org/10.1145/3689031.3717482) --- ### Towards Efficient Flash Caches with Emerging NVMe Flexible Data Placement SSDs *Michael Allison, Arun George, Javier González 0006, Dan Helmick *et al.** **TL;DR** — This paper shows how NVMe Flexible Data Placement (FDP) SSDs can be exploited by flash cache software to dramatically reduce write amplification and improve device lifetime. **Why notable** — FDP is a newly standardized NVMe feature; this is one of the first systems papers to demonstrate end-to-end integration with a production-grade flash caching stack, revealing concrete performance and endurance benefits that motivate wider adoption. [→ Read paper](https://doi.org/10.1145/3689031.3696091) --- ### Chrono: Meticulous Hotness Measurement and Flexible Page Migration for Memory Tiering *Zhenlin Qi, Shengan Zheng, Ying Huang, Yifeng Hui *et al.** **TL;DR** — Chrono introduces fine-grained, low-overhead hotness tracking and a flexible page migration policy that adapts to workload dynamics for tiered memory systems. **Why notable** — As CXL-based memory tiering becomes a reality in data centers, accurate hotness estimation is critical; Chrono's approach substantially outperforms existing kernel mechanisms and sets a new baseline for OS-level tiered memory management. [→ Read paper](https://doi.org/10.1145/3689031.3717462) --- ### Adios to Busy-Waiting for Microsecond-scale Memory Disaggregation *Wonsup Yoon, Jisu Ok, Sue Moon, Youngjin Kwon* **TL;DR** — This work eliminates CPU-wasting busy-waiting in disaggregated memory systems by designing interrupt-driven mechanisms that still meet microsecond latency targets. **Why notable** — Busy-waiting is the conventional wisdom for achieving low latency in disaggregated memory, yet it burns entire CPU cores; this paper challenges that assumption and shows interrupt-based designs can match latency while freeing substantial compute, which matters greatly at scale. [→ Read paper](https://doi.org/10.1145/3689031.3717475) --- ### Collaborative Text Editing with Eg-walker: Better, Faster, Smaller *Joseph Gentle, Martin Kleppmann* **TL;DR** — Eg-walker is a new CRDT algorithm for collaborative text editing that is simultaneously faster, more memory-efficient, and produces smaller operation logs than prior state-of-the-art CRDTs. **Why notable** — Collaborative editing CRDTs have been considered a mature area, making it surprising that Eg-walker achieves order-of-magnitude improvements across all key metrics; the result, from Martin Kleppmann, will likely become the new reference design for replicated text data structures. [→ Read paper](https://doi.org/10.1145/3689031.3696076) --- ### Ladon: High-Performance Multi-BFT Consensus via Dynamic Global Ordering *Hanzheng Lyu, Shaokang Xie, Jianyu Niu, Chen Feng 0001 *et al.** **TL;DR** — Ladon achieves high throughput in Byzantine fault-tolerant consensus by running multiple BFT instances in parallel and dynamically merging their outputs into a consistent global order. **Why notable** — Byzantine consensus is notoriously throughput-limited; Ladon's multi-instance approach with a novel global ordering layer demonstrates near-linear throughput scaling with the number of consensus instances, a significant advance for permissioned blockchain and critical-infrastructure scenarios. [→ Read paper](https://doi.org/10.1145/3689031.3696102) --- ### HybridFlow: A Flexible and Efficient RLHF Framework *Guangming Sheng, Chi Zhang 0022, Zilingfeng Ye, Xibin Wu *et al.** **TL;DR** — HybridFlow introduces a hybrid dataflow model for RLHF training that co-schedules the actor, critic, and reward models to maximize GPU utilization across heterogeneous cluster configurations. **Why notable** — RLHF has become central to LLM alignment yet existing frameworks map poorly to its multi-model, tightly coupled training loop; HybridFlow's design substantially improves end-to-end training throughput and provides a principled abstraction for future alignment training research. [→ Read paper](https://doi.org/10.1145/3689031.3696075) --- ### CacheBlend: Fast Large Language Model Serving for RAG with Cached Knowledge Fusion *Jiayi Yao, Hanchen Li, Yuhan Liu 0004, Siddhant Ray *et al.** **TL;DR** — CacheBlend reuses KV caches from multiple pre-computed document chunks and fuses them selectively at inference time, avoiding the quadratic cost of full re-encoding for retrieval-augmented generation. **Why notable** — RAG is a dominant LLM deployment pattern, but cache reuse across dynamically assembled contexts is unsolved; CacheBlend's selective fusion strategy delivers large time-to-first-token reductions with negligible quality degradation, directly improving the economics of production LLM serving. [→ Read paper](https://doi.org/10.1145/3689031.3696098) --- ### AlloyStack: A Library Operating System for Serverless Workflow Applications *Jianing You, Kang Chen, Laiping Zhao, Yiming Li *et al.** **TL;DR** — AlloyStack is a library OS tailored for serverless workflows that collapses function boundaries within a workflow into a single address space to eliminate inter-function communication overhead. **Why notable** — Serverless workflows suffer from high invocation and communication latency because each function is an isolated container; AlloyStack's library OS approach is a principled architectural answer that shows substantial end-to-end latency and cost improvements for real workflow benchmarks. [→ Read paper](https://doi.org/10.1145/3689031.3717490) --- ### CRAVE: Analyzing Cross-Resource Interaction to Improve Energy Efficiency in Systems-on-Chip *Dipayan Mukherjee, Sam Hachem, Jeremy Bao, Curtis Madsen *et al.** **TL;DR** — CRAVE models the cross-resource interference between CPU, GPU, and memory subsystems on SoCs to guide software-level energy optimization decisions. **Why notable** — Energy efficiency is increasingly a first-class constraint in both mobile and data center SoCs, yet interactions between on-chip resources are poorly understood at the software level; CRAVE's analysis framework reveals counter-intuitive interference patterns and enables measurable energy savings without hardware changes. [→ Read paper](https://doi.org/10.1145/3689031.3717498)