Nils Wilbert

M.Sc. Nils Wilbert

Wissenschaftlicher Mitarbeiter

Computer Engineering

Am Hubland

97074 Würzburg

Gebäude: M2

Raum: BH006/7

Telefon: +49 931 31-87941

E-Mail: nils.wilbert@uni-wuerzburg.de

Forschungsthemen:

Non-Volatile Memory (NVM)
Processing in Memory (PIM)

Publications

2025[ to top ]

CHaOS: A Persistent Lightweight Cache Hybridization-aware OS. Wilbert, Nils; Szymanski, Matthias; Wildermann, Stefan; Herzog, Henriette; Hönig, Timo; Teich, Jürgen. In Architecture of Computing Systems, Vol. 38. Springer Nature Switzerland, 2025.
- [ BibTeX ]
@inproceedings{wilbert2025chaos, abstract = {Computer systems are prone to crashes and power outages, particularly in intermittent computing scenarios where embedded systems rely on unreliable energy-harvesting sources. Hybrid caches, which integrate volatile and non-volatile memory (NVM) sections, offer opportunities for efficient operating system (OS) services to ensure data persistence over power interruptions. However, the lack of OS awareness of hybrid cache structures can result in inefficient backups, data loss and inconsistencies, as well as underutilization of the potential of hybrid caches. This paper introduces the Cache Hybridization-aware Operating System (CHaOS), that is based on a co-design of the OS and the underlying hardware to systematically persist volatile states and data in case of power outages. Our evaluation demonstrates that CHaOS not only proves robust against power outages, but also can significantly reduce the backup latency. In our test of using CHaOS to execute an image processing application on a hybrid-cache system, already with 75% of caches being non-volatile, the backup latency drops to only 8.2% compared to a completely volatile cache. At the same time, the energy demand could be reduced due to lower static power consumption of NVM technology. Our investigations validate the feasibility of CHaOS and establish a strong foundation for future research.}, author = {Wilbert, Nils and Szymanski, Matthias and Wildermann, Stefan and Herzog, Henriette and Hönig, Timo and Teich, Jürgen}, booktitle = {Architecture of Computing Systems}, keywords = {myown}, publisher = {Springer Nature Switzerland}, title = {CHaOS: A Persistent Lightweight Cache Hybridization-aware OS}, volume = 38, year = 2025 }

2024[ to top ]

To Keep or Not to Keep - The Volatility of Replacement Policy Metadata in Hybrid Caches. Wilbert, Nils; Wildermann, Stefan; Teich, Jürgen. In Proceedings of the 2nd Workshop on Disruptive Memory Systems, pp. 17–24. 2024.
- [ BibTeX ]
- [ DOI ]
@inproceedings{faucris.328840998, author = {Wilbert, Nils and Wildermann, Stefan and Teich, Jürgen}, booktitle = {Proceedings of the 2nd Workshop on Disruptive Memory Systems}, keywords = {from:myzinsky}, pages = {17 - 24}, title = {{To} {Keep} or {Not} to {Keep} - {The} {Volatility} of {Replacement} {Policy} {Metadata} in {Hybrid} {Caches}}, year = 2024 }
Hybrid Cache Design Under Varying Power Supply Stability - A Comparative Study. Wilbert, Nils; Wildermann, Stefan; Teich, Jürgen. In MEMSYS ’24: Proceedings of the International Symposium on Memory Systems, pp. 257–269. 2024.
- [ BibTeX ]
- [ DOI ]
@inproceedings{faucris.326778945, abstract = {co<br /></p><pre>As emerging Non-Volatile Memory (NVM) technologies are ever maturing, the usage of such novel memory technologies in embedded systems is becoming increasingly viable. Especially when introduced at the cache level, these technologies can promise great advantages over conventional SRAM technology as they can serve read requests at lower energy and, in applications of intermittent computing, reduce the backup overhead during a power outage. Nevertheless, write accesses to NVMs consume more energy compared to writing to a conventional SRAM. As a remedy, hybrid caches, introducing both NVM and SRAM to the cache hierarchy, can realize trade-offs by minimizing the expected NVM write overhead while still exploiting the NVM read efficiency and non-volatility property. However, these hybrid designs open up a number of additional decisions in the design space, which are examined in this paper. Most notably, the choice of the degree of non-volatility introduced to the cache hierarchy in addition to the choice of a suitable cache replacement policy has not been analyzed and solved systematically yet. By employing simulation-based experiments, we evaluate embedded applications featuring various memory access patterns under both continuous and intermittent power supplies for different types of hybrid cache designs. Our results show how the combination of application and architecture characteristics, in addition to the expected power supply stability, leads to a vast range of hard-to-predict cache effects affecting both performance and energy efficiency. Both the potential and a necessity for automated design tools, including the exploration of hybrid memory hierarchies, therefore arise.}, author = {Wilbert, Nils and Wildermann, Stefan and Teich, Jürgen}, booktitle = {MEMSYS '24: Proceedings of the International Symposium on Memory Systems}, keywords = {cache}, pages = {257–269}, title = {{Hybrid} {Cache} {Design} {Under} {Varying} {Power} {Supply} {Stability} - {A} {Comparative} {Study}}, year = 2024 }

Hubland Süd, Geb. M2

M.Sc. Nils Wilbert

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