> I truly believe that priority inheritance on counting semaphores should be
explicitly enabled (disabled by default) and enabling it by default might lead to unexpected priority boost for low priority tasks that violates real-time requirements. It has been enabled by default since day one so nothing will be broken. Disabling it now will break things – that is an orthogonal discussion to spec compliance. Currently, priorioty inheritance is explicitly disabled in all places where it should not be enabled (i.e., signaling semahores). If the default changes, then you would need to explicitly enable prority inheritance on all semaphores that are used as locks in order to retain the previous behavior. See https://cwiki.apache.org/confluence/display/NUTTX/Signaling+Semaphores+and+Priority+Inheritance – the POSIX definition does not have this issue because POSIX does not support priority inheritance on counting semaphores.
