Kono, Kenji

写真a

Affiliation

Faculty of Science and Technology, Department of Information and Computer Science (Yagami)

Position

Professor

Related Websites
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Career 【 Display / hide 】

  • 1995.04
    -
    1997.10

    DC1, Japan Society of the Promotion of Science

  • 1997.11
    -
    1999.12

    University of Tokyo, 理学系研究科情報科学専攻, 助手

  • 1999.10
    -
    2002.09

    PRESTO, Japan Science and Technology Corporation

  • 2000.01
    -
    2003.03

    Assistant Professor of the University of Electro-Communications

  • 2003.04
    -
    2005.03

    Associate Professor of the University of Electro-Communications

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Academic Background 【 Display / hide 】

  • 1993.03

    The University of Tokyo, Faculty of Science, Department of Computer Science

    University, Graduated

  • 1995.03

    The University of Tokyo, Graduate School, Division of Science, Computer Science

    Graduate School, Completed, Master's course

  • 1997.10

    The University of Tokyo, Graduate School, Division of Science, Computer Science

    Graduate School, Withdrawal before completion, Doctoral course

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Academic Degrees 【 Display / hide 】

  • Doctor of Science, The University of Tokyo, Dissertation, 2000.01

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Research Areas 【 Display / hide 】

  • Informatics / Computer system (System Software)

  • Informatics / Software (ソフトウエア)

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Research Keywords 【 Display / hide 】

  • operating systems

  • security

  • distributed systems

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Books 【 Display / hide 】

  • Handbook of Software Aging and Rejuvenation

    Kenji Kono, Kenichi Kourai, Hiroshi Yamada, World Scientific Publishing, 2020

    Scope: Chap. 9

  • コンピュータ・システム プログラマの視点から

    五島 正裕，河野健二，南出靖彦, 丸善出版, 2019.02

  • Open Systems Dependability

    Kenji Kono, Hiroshi Yamada, CRC Press, 2015

    Scope: Chap. 7.4

  • Engineering the Computer Science and IT

    Manabu Hirano, Takeshi Okuda, Eiji Kawai, Takahiro Shinagawa, Hideki Eiraku, Kouichi Tanimoto, Shoichi Hasegawa, Takashi Horie, Seiji Mune, Kazumasa Omote, Kenichi Kourai, Yoshihiro Oyama, Kenji Kono, Shigeru Chiba, Yasushi Shinjo, Kazuhiko Kato, Suguru Yamaguchi, 2009.10

    Scope: 477-488

  • オペレーティングシステムの仕組み

    KONO KENJI, 2007.10

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Papers 【 Display / hide 】

  • Revisiting Memory Swapping for Big-Memory Applications

    Kida S., Imamura S., Kono K.

    Proceedings of International Conference on High Performance Computing in Asia-Pacific Region, HPC Asia 2025    33 - 42 2025.03

    　View Summary

    Big-memory applications which have huge memory footprints, such as machine learning and key-value store, are playing important roles in various real-world services. Compute Express Link-based memory (CXL memory) is nowadays attracting a lot of attention for such applications, because it can expand memory capacity on a single machine with fast memory semantic accesses to memory devices attached to PCIe slots. On the other hand, memory swapping is another traditional technique to expand memory capacity by using storage devices as a swap space. It is well known that memory swapping causes a large latency overhead to swap-in/out memory pages from/to storage devices, while it can efficiently utilize main memory when workloads have skewed memory access patterns.In this paper, we quantitatively compare the throughput of 14 macro-benchmarks between CXL memory emulated with a remote NUMA node and memory swapping with an NVMe SSD. Through this evaluation, the benchmarks are classified into three categories, where memory swapping achieves a comparable or higher throughput compared to emulated CXL memory for 9 benchmarks. This result reminds us that memory swapping with SSDs, which are much cheaper than CXL memory devices, is still a good option for memory capacity expansion. In addition, we conduct an in-depth analysis on the characteristics of emulated CXL memory and memory swapping using our synthetic benchmark. The analysis shows that memory swapping is not sensitive to the initial placement of hot data and achieves a comparable throughput to emulated CXL memory when hot data is accessed intensively.

  • PvCC: A vCPU Scheduling Policy for DPDK-applied Systems at Multi-Tenant Edge Data Centers

    Tsujimoto Y., Sato Y., Yasukata K., Ishiguro K., Kono K.

    Middleware 2024 - Proceedings of the 25th ACM International Middleware Conference    379 - 391 2024.12

    　View Summary

    This paper explores a practical means to employ Data Plane Development Kit (DPDK), a kernel-bypassing framework for packet processing, in resource-limited multi-tenant edge data centers. The problem is that the traditional virtual CPU (vCPU) schedulers are not well compatible with the event detection model of DPDK, which needs to monopolize a physical CPU (pCPU) for NIC register polling. Consequently, DPDK-applied systems running on consolidated Virtual Machines (VMs), a common setup at edges, fail to achieve low serving latencies regardless of the use of DPDK. Toward edge data center providers, this work presents a new vCPU scheduling policy named Polling vCPU Consolidation (PvCC) which runs DPDK-applied systems on dedicated pCPUs adopting microsecond-scale time slices. Along with this, we introduce a mechanism to determine an appropriate number of dedicated pCPUs according to customers’ demands represented through a newly introduced vCPU scaling API enabling customers to scale up/down the vCPUs of their VMs at runtime. Our experiments show that PvCC allows DPDK-applied systems running on consolidated VMs to achieve low serving latencies, and our vCPU scaling API enables customers to adjust CPU resource assignment according to the incoming request rate and providers to effectively assign spare pCPUs to VMs executing non-latency-sensitive best-effort tasks.

  • Balancing Analysis Time and Bug Detection: Daily Development-friendly Bug Detection in Linux

    Suzuki K., Ishiguro K., Kono K.

    Proceedings of the 2024 USENIX Annual Technical Conference, ATC 2024    493 - 508 2024

    　View Summary

    Linux, a battle-tested codebase, is known to suffer from many bugs despite its extensive testing mechanisms. While many of these bugs require domain-specific knowledge for detection, a significant portion matches well-known bug patterns. Even though these bugs can be found with existing tools, our simple check of Linux kernel patches suggests that these tools are not used much in the developer’s daily workflow. The lack of usage is probably due to the well-known trade-off between analysis time and bug detection capabilities: tools typically employ complex analysis to effectively and comprehensively find bugs in return for a long analysis time, or focus on a short analysis time by only employing elementary analyses and thus can only find a very limited number of bugs. Ideally, developers expect the tools to incur short analysis time, while still finding many bugs to use them in daily development. This paper explores an approach that balances this tradeoff by focusing on bugs that can be found with less computationally-complex analysis methods, and limiting the scope to each source code. To achieve this, we propose a combination of computationally lightweight analyses and demonstrate our claim by designing FiTx, a framework for generating daily development-friendly bug checkers that focus on well-known patterns. Despite its simplicity, FiTx successfully identified 47 new bugs in the Linux kernel version 5.15 within 2.5 hours, outperforming Clang Static Analyzer and CppCheck in both speed and bug detection. It demonstrates that focusing on less complex bug patterns can still significantly contribute to the improvement of codebase health. FiTx can be embedded into the daily development routine, enabling early bug detection without sacrificing developers’ time.

  • Revisiting VM-Agnostic KVM vCPU Scheduler for Mitigating Excessive vCPU Spinning

    Ishiguro K., Yasuno N., Aublin P.L., Kono K.

    IEEE Transactions on Parallel and Distributed Systems 34 ( 10 ) 2615 - 2628 2023.10

    ISSN  10459219

    　View Summary

    In virtualized environments, virtual CPUs (vCPUs) are commonly oversubscribed on physical CPUs (pCPUs) to utilize CPU resources efficiently. However, excessive vCPU spinning, which occurs when a vCPU is waiting in a spin loop for an event from a descheduled vCPU, greatly degrades application performance in virtualized environments. VM-agnostic hypervisors aim to prevent excessive vCPU spinning by rescheduling vCPUs when an excessive spin is detected by hardware support for virtualization. We investigate the effectiveness of the KVM vCPU scheduler and show that it fails to avoid excessive vCPU spinning under various situations. We identify three problems: 1) scheduler mismatch, 2) aggressive limitation of candidate vCPUs, and 3) IPI context misuse. The first problem stems from the mismatch between the KVM vCPU scheduler and the Linux scheduler. The second and third problems come from failures in choosing candidate vCPUs to be scheduled next. Our in-depth analysis reveals simple modification to KVM (89 LoC) can mitigate excessive vCPU spinning. Our simple modification reduces excessive vCPU spinning by up to 96% and improves benchmark performance by up to 2.6×. Part of the proposed mitigation has been integrated with KVM from Linux KVM v5.13 onward.

  • Nioh-PT: Virtual I/O Filtering for Agile Protection against Vulnerability Windows

    Mana Senuki, Kenta Ishiguro, Kenji Kono

    ACM Symposium on Applied Computing (SAC)    1293 - 1300 2023.03

    Accepted

    　View Summary

    Hypervisor vulnerabilities cause severe security issues in multi-tenant cloud environments because hypervisors guarantee isolation among virtual machines (VMs). Unfortunately, hypervisor vulnerabilities are continuously reported, and device emulation in hypervisors is one of the hotbeds because of its complexity. Although applying patches to fix the vulnerabilities is a common way to protect hypervisors, it takes time to develop the patches because the internal knowledge on hypervisors is mandatory. The hypervisors are exposed to the threat of the vulnerabilities exploitation until the patches are released.This paper proposes Nioh-PT, a framework for filtering illegal I/O requests, which reduces the vulnerability windows of the device emulation. The key insight of Nioh-PT is that malicious I/O requests contain illegal I/O sequences, a series of I/O requests that are not issued during normal I/O operations. Nioh-PT filters out those illegal I/O sequences and protects device emulators against the exploitation. The filtering rules, which define illegal I/O sequences for virtual device exploits, can be specified without the knowledge on the internal implementation of hypervisors and virtual devices, because Nioh-PT is decoupled from hypervisors and the device emulators. We develop 11 filtering rules against four real-world vulnerabilities in device emulation, including CVE-2015-3456 (VENOM) and CVE-2016-7909. We demonstrate that Nioh-PT with these filtering rules protects against the virtual device exploits and introduces negligible overhead by up to 8% for filesystem and storage benchmarks.

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Papers, etc., Registered in KOARA 【 Display / hide 】

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Reviews, Commentaries, etc. 【 Display / hide 】

  • Introduction to the Special Issue on Survey Papers from Doctoral Dissertaions

    Igarashi Y., Kawabata H., Kono K., Chiba S., Nakazawa J., Hayashi S.

    Computer Software 39 ( 3 )  2022

    ISSN  02896540

  • オペレーティングシステムのエージングと若化

    河野 健二，山田浩史

    日本信頼性学会誌「信頼性」 36 ( 1 ) 24 - 31 2014.01

    Article, review, commentary, editorial, etc. (scientific journal), Joint Work

  • Oops! What about a Million Kernel Oopses?

    Lisong Guo, Peter Senna Tschudin, Kenji Kono, Gilles Muller, Julia Lawall

    Research Report, No. 436 (INRIA)   2013.06

    Internal/External technical report, pre-print, etc., Joint Work

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Presentations 【 Display / hide 】

  • データセンタ間通信による性能低下を抑えたキーバリューストア構築手法

    堀江 光、浅原 理人、山田 浩史、河野 健二

    情報処理学会 OS 研究会, 

    2014.03
    , 

    Oral presentation (general)

  • 仮想化環境におけるメモリ情報に着目したページシェアリング効率化手法

    井上 宗士、山田 浩史、河野 健二

    情報処理学会 OS 研究会, 

    2014.03
    , 

    Oral presentation (general)

  • 仮想マシン移送における移送コストの定量的調査

    古藤 明音、山田 浩史、河野 健二

    情報処理学会 OS 研究会, 

    2014.03
    , 

    Oral presentation (general)

  • 需要の集中を考慮した分散 Key-Value Store におけるレプリカの動的配置手法

    白松 幸起、河野 健二、堀江 光

    情報処理学会 OS 研究会, 

    2014.03
    , 

    Oral presentation (general)

  • データセンタ間通信による性能低下を抑えたキーバリューストア構築手法

    堀江光，浅原理人，山田浩史，河野健二

    日本ソフトウェア科学会 DSW ワークショップ, 

    2013.12
    , 

    Poster presentation

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Research Projects of Competitive Funds, etc. 【 Display / hide 】

  • 超分散コンピューティング基盤の研究開発

    2023.04
    -
    2028.03

    NEDO, Coinvestigator(s)

  • Persistent TEE: データ・プライバシ保護のための堅牢な実行基盤

    2023.04
    -
    2026.03

    科研費 基盤 (B), Principal investigator

  • デジタルツインを用いた自動運転AIの検証と妥当性確認

    2022.04
    -
    2024.03

    AIP加速, Coinvestigator(s)

  • レガシーコードの実行回避によるハイパーバイザの安全性向上

    2019.04
    -
    2022.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator

  • 完全自動運転における危険と異常の予測

    2016.10
    -
    2022.03

    CREST, Coinvestigator(s)

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Awards 【 Display / hide 】

  • 日本ソフトウェア科学会基礎研究賞

    2016

    Type of Award： Award from Japanese society, conference, symposium, etc.

  • IBM Faculty Award

    2015

    Type of Award： International academic award (Japan or overseas)

  • 日本ソフトウェア科学会ソフトウェア論文賞

    2014.09

    Type of Award： Award from Japanese society, conference, symposium, etc.

  • 情報処理学会論文賞

    2013.05

    Type of Award： Award from Japanese society, conference, symposium, etc.

  • 情報処理学会論文賞

    KONO KENJI, 2010.05

    Type of Award： Award from Japanese society, conference, symposium, etc.

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Courses Taught 【 Display / hide 】

  • TOPICS IN COMPUTER OPERATING SYSTEMS

    2025

  • RECITATION IN INFORMATION AND COMPUTER SCIENCE

    2025

  • OPERATING SYSTEMS

    2025

  • INTRODUCTION TO INFORMATICS

    2025

  • INDEPENDENT STUDY ON SCIENCE FOR OPEN AND ENVIRONMENTAL SYSTEMS

    2025

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Social Activities 【 Display / hide 】

  • 内閣官房OS機能調査委員会

    2005
    -
    2006

  • 内閣官房情報セキュリティ対策推進室委託調査

    2005

  • 財団法人 防衛技術協会 電子政府におけるセキュリティに配慮したOS等に関する調査研究委員会

    2004
    -
    Present

  • 国立情報学研究所

    2003
    -
    Present

  • 社団法人 電子情報技術産業協会(JEITA) 情報システム技術委員会

    2003
    -
    Present

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Memberships in Academic Societies 【 Display / hide 】

  • IEEE International Conference on Distributed Computing Systems, 

    2011
    -
    Present

  • 日本ソフトウェア科学会, 

    2010
    -
    2012

  • IEEE Pacific Rim Int'l Symp. on Dependable Computing, 

    2010

  • 日本ソフトウェア科学会 ディペンダブルシステム研究会, 

    2009
    -
    2012.03

  • Int'l Conf. on Frontier of Computer Science and Technology, 

    2009
    -
    2010

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Committee Experiences 【 Display / hide 】

  • 2011.04
    -
    2015.03

    主査, 情報処理学会システムソフトウェアとオペレーティングシステム研究会

  • 2011
    -
    2012

    Program Committee Member, IEEE International Conference on Distributed Computing Systems

  • 2010
    -
    2012

    Director, 日本ソフトウェア科学会

  • 2010

    PC Member, IEEE Pacific Rim Int'l Symp. on Dependable Computing

  • 2009
    -
    2012.03

    Program Chair, 日本ソフトウェア科学会 ディペンダブルシステム研究会

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