Seminarium: Systemy Rozproszone
9 października 2025 12:15, sala 4070
W prezentacji przedstawię system 1KT, jego działanie oraz wyzwania związane ze zdalną aktualizacją oprogramowania. Omówię podjęte próby wykonania aktualizacji w ramach mojej pracy magisterskiej zatytułowanej "Projekt i wdrożenie niezawodnych procedur zdalnej aktualizacji oprogramowania zarządzającego urządzeniami o ograniczonych zasobach w rozproszonej wielkoskalowej platformie eksperymentalnej Internetu Rzeczy" oraz napotkane problemy i trudności w jej realizacji.
Zapraszam,
Artur Kamieniecki
Microkernel-based operating systems are robust thanks to most of their complexity being shifted from the kernel and divided into multiple cooperative user-space processes. This provides memory isolation, allowing for greater overall system stability and safety, but comes at a price – the performance of the whole system is now dependent on the efficiency of kernel-managed inter-process communication (IPC) primitives. Classic communication via IPC requires complex kernel intervention (various validity checks, context switching, memory copying, invoking a scheduler, etc.), thus it cannot compete with the performance of direct memory sharing between threads executed in system mode.
First generations of microkernels suffered greatly from performance overhead of IPC, and the issue has been deeply studied since the 1990s. Modern implementations – such as QNX OS, or L4 microkernel family members (i.e. NOVA, seL4, L4Re/Fiasco.OC) – all exhibit various approaches to IPC optimization (optimized system call semantics, shared memory usage, scheduler bypass, thread migration and more), but they are often mutually exclusive, due to differences in system architectures, or do not support platforms without Memory Management Unit (MMU).
During my presentation I will briefly introduce the advancements of the last 30 years in microkernel design and discuss the performance of state-of-the-art implementations. I will then present my current state of things and challenges with optimizing the IPC in the Phoenix-RTOS - an open-source microkernel-based real-time operating system developed commercially by Phoenix Systems - a task I work on as part of my master's thesis.
Zapraszam,
Adam Greloch