@misc{RamsauerBulwahnLohmannetal., author = {Ramsauer, Ralf and Bulwahn, Lukas and Lohmann, Daniel and Mauerer, Wolfgang}, title = {The Sound of Silence: Mining Security Vulnerabilities from Secret Integration Channels in Open-Source Projects}, series = {MiniDebConf Regensburg (MDC) 2021}, journal = {MiniDebConf Regensburg (MDC) 2021}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, language = {en} } @misc{RamsauerKiszkaMauerer, author = {Ramsauer, Ralf and Kiszka, Jan and Mauerer, Wolfgang}, title = {Building Mixed Criticality Linux Systems with the Jailhouse Hypervisor}, series = {Embedded Lunux Conference + OpenIoTSummit, Portland, OR, 21.-23.02.2017}, journal = {Embedded Lunux Conference + OpenIoTSummit, Portland, OR, 21.-23.02.2017}, abstract = {The partitioning hypervisor Jaihouse allows us to run safety critical and uncritical applications in parallel on a single SoC. We present our experiences when porting a safety and real-time critical existing application as a Jailhouse guest. It shows a novel and promising approach for implementing mixed-criticality applications with real-time requirement while not loosing the benefits of Linux. This is done by static partitioning of hardware resources; guests do not interfere. We will present a multicopter platform running the real-time critical flight stack in an isolated Jailhouse guest. This proves the practicability of Jailhouse as well as the suitability for real-time safety critical systems by porting an existing application to a Jailhouse cell. We stress its concept and show up current hardware limitations, like undesired behaviour and present possible workarounds and solutions.}, language = {en} } @misc{RamsauerDudaBulwahnetal., author = {Ramsauer, Ralf and Duda, Sebastian and Bulwahn, Lukas and Mauerer, Wolfgang}, title = {The list is our process! An analysis of the kernel's email-based development process}, series = {Embedded Linux Conference Europe, Lyon 28.10.2019}, journal = {Embedded Linux Conference Europe, Lyon 28.10.2019}, language = {en} } @misc{RamsauerDudaMauereretal., author = {Ramsauer, Ralf and Duda, Sebastian and Mauerer, Wolfgang and Bulwahn, Lukas}, title = {The list is our process: An analysis of the kernel's email-based development process}, series = {Linux Plumbers Conference, Lisbon September 9, 2019}, journal = {Linux Plumbers Conference, Lisbon September 9, 2019}, language = {en} } @misc{RamsauerKiszkaLohmannetal., author = {Ramsauer, Ralf and Kiszka, Jan and Lohmann, Daniel and Mauerer, Wolfgang}, title = {Implementierung gemischt kritischer Systeme durch statische Hardwarepartitionierung}, series = {Fr{\"u}hjahrstreffen der Fachgruppen Betriebssysteme, Hannover, 2. M{\"a}rz 2018}, journal = {Fr{\"u}hjahrstreffen der Fachgruppen Betriebssysteme, Hannover, 2. M{\"a}rz 2018}, language = {de} } @misc{RamsauerKiszkaMauerer, author = {Ramsauer, Ralf and Kiszka, Jan and Mauerer, Wolfgang}, title = {Spectre and Meltdown vs. Real-Time: How Much do Mitigations Cost?}, series = {Embedded Linux Conference Europe 2018, October 22 - 24, 2018, Edinburgh, UK}, journal = {Embedded Linux Conference Europe 2018, October 22 - 24, 2018, Edinburgh, UK}, language = {en} } @misc{RamsauerLohmannMauerer, author = {Ramsauer, Ralf and Lohmann, Daniel and Mauerer, Wolfgang}, title = {Quantifying Upstream Integration with PaStA}, series = {LTSI Workshop @ ELC17}, journal = {LTSI Workshop @ ELC17}, language = {en} } @misc{MintelRamsauerLohmannetal., author = {Mintel, Mario and Ramsauer, Ralf and Lohmann, Daniel and Scherzinger, Stefanie and Mauerer, Wolfgang}, title = {Fork {\`a} la carte f{\"u}r In-Memory-Datenbanken}, series = {Fr{\"u}hjahrstreffen der Fachgruppen Betriebssysteme, Hamburg, 17. M{\"a}rz 2022}, journal = {Fr{\"u}hjahrstreffen der Fachgruppen Betriebssysteme, Hamburg, 17. M{\"a}rz 2022}, language = {de} } @misc{MauererRamsauerKoelbl, author = {Mauerer, Wolfgang and Ramsauer, Ralf and K{\"o}lbl, Andreas}, title = {The Many Approaches to Real-Time and Safety-Critical Linux}, series = {Open Source Summit Japan 2017}, journal = {Open Source Summit Japan 2017}, language = {en} } @inproceedings{RamsauerLohmannMauerer, author = {Ramsauer, Ralf and Lohmann, Daniel and Mauerer, Wolfgang}, title = {The List is the Process: Reliable Pre-Integration Tracking of Commits on Mailing Lists}, series = {2019 IEEE/ACM 41st International Conference on Software Engineering (ICSE), 25-31 May 2019, Montreal, QC, Canada}, booktitle = {2019 IEEE/ACM 41st International Conference on Software Engineering (ICSE), 25-31 May 2019, Montreal, QC, Canada}, publisher = {IEEE}, doi = {10.1109/ICSE.2019.00088}, pages = {807 -- 818}, abstract = {A considerable corpus of research on software evolution focuses on mining changes in software repositories, but omits their pre-integration history. We present a novel method for tracking this otherwise invisible evolution of software changes on mailing lists by connecting all early revisions of changes to their final version in repositories. Since artefact modifications on mailing lists are communicated by updates to fragments (i.e., patches) only, identifying semantically similar changes is a non-trivial task that our approach solves in a language-independent way. We evaluate our method on high-profile open source software (OSS) projects like the Linux kernel, and validate its high accuracy using an elaborately created ground truth. Our approach can be used to quantify properties of OSS development processes, which is an essential requirement for using OSS in reliable or safety-critical industrial products, where certifiability and conformance to processes are crucial. The high accuracy of our technique allows, to the best of our knowledge, for the first time to quantitatively determine if an open development process effectively aligns with given formal process requirements.}, language = {en} } @inproceedings{MauererRamsauerLucasetal., author = {Mauerer, Wolfgang and Ramsauer, Ralf and Lucas, Edson R. F. and Scherzinger, Stefanie}, title = {Silentium! Run-Analyse-Eradicate the Noise out of the DB/OS Stack}, series = {Datenbanksysteme f{\"u}r Business, Technologie und Web (BTW 2021): 13.-17. September 2021, Dresden, Deutschland}, booktitle = {Datenbanksysteme f{\"u}r Business, Technologie und Web (BTW 2021): 13.-17. September 2021, Dresden, Deutschland}, publisher = {Gesellschaft f{\"u}r Informatik}, doi = {10.18420/btw2021-21}, pages = {397 -- 421}, abstract = {When multiple tenants compete for resources, database performance tends to suffer. Yet there are scenarios where guaranteed sub-millisecond latencies are crucial, such as in real-time data processing, IoT devices, or when operating in safety-critical environments. In this paper, we study how to make query latencies deterministic in the face of noise (whether caused by other tenants or unrelated operating system tasks). We perform controlled experiments with an in-memory database engine in a multi-tenant setting, where we successively eradicate noisy interference from within the system software stack, to the point where the engine runs close to bare-metal on the underlying hardware. We show that we can achieve query latencies comparable to the database engine running as the sole tenant, but without noticeably impacting the workload of competing tenants. We discuss these results in the context of ongoing efforts to build custom operating systems for database workloads, and point out that for certain use cases, the margin for improvement is rather narrow. In fact, for scenarios like ours, existing operating systems might just be good enough, provided that they are expertly configured. We then critically discuss these findings in the light of a broader family of database systems (e.g., including disk-based), and how to extend the approach of this paper accordingly. Low-latency databases; tail latency; real-time databases; bounded-time query processing; DB-OS co-engineering}, language = {de} }