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--- realtime [03/26/2018 15:30] – admin
+++ realtime [06/09/2026 18:45] (current) – admin
@@ Line 1: / Line 1: @@
 https://wiki.linuxfoundation.org/realtime/rtl/start
 https://wiki.linuxfoundation.org/realtime/rtl/all_topics
+https://www.embedded-software-engineering.de/entwicklung-einer-linux-realtime-applikation-a-b862ea485a877e6a7e2f25edd98f5ef7/
+{{:screenshot_from_2026-06-09_20-43-34.png?direct&400|}}
+====== Learning ======
+https://realtime-linux.org/a-checklist-for-real-time-applications-in-linux/
+https://bootlin.com/training/preempt-rt/
+====== Core partitioning ======
+User-space partitioning, core isolation, NO_HZ_FULL
+Dual-OS partitioning, using a POSIX RTOS in some cores, over a hypervisor
+https://yosh.ke.mu/raspberry_pi_isolating_cores_in_linux_kernel
+====== Multitasking ======
+In user space:
+  * Process (fork)
+  * Thread (pthread_create)
+In kernel:
+  * Kernel thread (kthreadd)
+====== Scheduler ======
+sched_class
+stop > dl > rt > cfs > idle
+(e.g. rt threads will run with higher priority than cfs threads)
+(stop and idle scheduling class are not accessible for user space applications)
+rt includes SCHED_FIFO and SCHED_RR policies.
+dl includes SCHED_DEADLINE policy (augmented EDF).
+====== Utilities ======
+  * chrt
+  * taskset
+==== Linux specific APIs ====
+  * sched_setattr
+  * sched_setaffinity
+  * CPU_SET
+  * pthread_setaffinity_np
+==== POSIX realtime APIs ====
+  * sched_setscheduler
+  * ...
+==== Benchmarking ====
+Latency measurement with **cyclictest** (results for SCHED_FIFO).
+Sources of latency:
+  * Kernel system call
+  * ISR
+  * Kernel locks
+  * Priority inversions
+  * Timers
+  * Page faults
+**Ftrace**
+**Kernel Shark**
+**LLTng**