Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2507.18559

Optimizing Tree-structure Indexes for CXL-based Heterogeneous Memory with SINLK

Haoru Zhao·Mingkai Dong·Fangnuo Wu·Haibo Chen
View original source ↗Read source document ↗Export metadata ↓

Abstract

On heterogeneous memory (HM) where fast memory (i.e., CPU-attached DRAM) and slow memory (e.g., remote NUMA memory, RDMA-connected memory, Persistent Memory (PM)) coexist, optimizing the placement of tree-structure indexes (e.g., B+tree) is crucial to achieving high performance while enjoying memory expansion. Nowadays, CXL-based heterogeneous memory (CXL-HM) is emerging due to its high efficiency and memory semantics. Prior tree-structure index placement schemes for HM cannot effectively boost performance on CXL-HM, as they fail to adapt to the changes in hardware characteristics and semantics. Additionally, existing CXL-HM page-level data placement schemes are not efficient for tree-structure indexes due to the granularity mismatch between the tree nodes and the page. In this paper, we argue for a CXL native, tree-structure aware data placement scheme to optimize tree-structure indexes on CXL-HM. Our key insight is that the placement of tree-structure indexes on CXL-HM should match the tree's inherent characteristics with CXL-HM features. We present SINLK, a tree-structure aware, node-grained data placement scheme for tree-structure indexes on CXL-HM. With SINLK, developers can easily adapt existing tree-structure indexes to CXL-HM. We have integrated the B+tree and radix tree with SINLK to demonstrate its effectiveness. Evaluations show that SINLK improves throughput by up to 71% and reduces P99 latency by up to 81% compared with state-of-the-art data placement schemes (e.g., MEMTIS) and HM-optimized tree-structure indexes in YCSB and real-world workloads.

Explore related subjects

cs.OS

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Haoru Zhao, Mingkai Dong, Fangnuo Wu, Haibo Chen. 2025-07-24. Optimizing Tree-structure Indexes for CXL-based Heterogeneous Memory with SINLK. https://arxiv.org/abs/2507.18559

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Don't Let AI Agents YOLO Your Files: Information and Control in Agent-Native Filesystems

AI coding agents regularly misuse their filesystem access, causing data corruption, loss, and leakage. We conduct the first systematic study of this problem through an analysis of 290 public reports. Our study reveals two fundamental gaps: users and agents have limited information about filesystem effects and insufficient control over them. To close these gaps, we propose to shift information and control from agents to filesystems. We introduce agent-native filesystems and identify three primitives they should provide: introspect effects, undo mutations, and gate accesses. These primitives let agents operate autonomously while reserving user interaction for sensitive accesses and final review. We build YoloFS, an agent-native filesystem. YoloFS stages mutations until the user commits them, snapshots intermediate states for agent self-correction, and uses progressive permission to let users adapt access rules during execution. We evaluate YoloFS with a new methodology that captures interactions among the user, agent, and filesystem. On 11 tasks with hidden side effects, YoloFS enables agents to self-correct in 8 and stages all mutations for user review. On 112 routine tasks, YoloFS reduces user interaction while matching the baseline success rate. YoloFS is open-sourced at https://github.com/YoloFS/YoloFS.

cs.OS↗
arXiv2026

Netkit: Specializing Linux Packet Delivery for Container Networks

Cloud-native microservices architectures rely on network namespaces for isolation, with the overhead of container communications remaining a critical performance bottleneck. While colocating containers on the same host mitigates some of this overhead, it cannot match the performance of communication within a single network namespace. Existing solutions either require application rewrites or fail to support the full Linux network stack expected by containerized applications. In this paper, we present netkit, an eBPF-based datapath that specializes the Linux networking stack to eliminate redundant backlog queue traversals during network namespace transitions. netkit leverages eBPF to transparently redirect packets between namespaces, bypassing unnecessary buffering while preserving compatibility with existing container applications. Our implementation in the Linux kernel, integrated with minimal changes to the Cilium network plugin for Kubernetes, improves throughput by up to 37\% and achieves parity between container-to-container and process-to-process communications, effectively closing the performance gap introduced by namespace isolation.

cs.OS↗
arXiv2026

Grouper: Scheduling Groups for Multi-Tenant Microsecond-Scale Microservices

Microsecond-scale core allocation makes colocating latency-critical services with batch work worthwhile. A thread that finds no work parks within microseconds and its core goes to a batch task. Putting one back costs $\sim$18 $μ$s, as the allocator must discover that a core is wanted and then take it from the batch task holding it. A monolith pays that tax once per request, a microservice chain pays it at every hop in both directions, and a multi-tenant host multiplies it again, because every tenant's hops queue at the same allocator. On our port of DeathStarBench's hotelReservation, going from two tenants to ten takes a hop from 39 to 222 $μ$s and a 10-RPC path's median from 456 to 2,445 $μ$s, a fivefold degradation even though no tenant's own load changed. We introduce Grouper and the scheduling group, a set of isolated runtimes that the allocator treats as one allocation and accounting unit, whose members may hand cores directly to one another. A service sending an RPC donates its core to the peer through an unprivileged kernel fast path, so the core follows the request through the call graph. The allocator retains control through reconciliation, core-addressed revocation and a pooled budget but leaves the critical path; its load falls from $Θ(R \cdot H)$ to $Θ(R)$ in request rate $R$ and hop count $H$. Over a grid of two to ten tenants at 1,000-30,000 requests per second each, Grouper outperforms Caladan (the allocator Junction also builds on) and Linux by up to 7.9$\times$ and 3.4$\times$ at the median and 4.1$\times$ and 14.2$\times$ at the tail, and leaves batch work more throughput than Caladan at over 70% of load points.

cs.OS↗