More background: https://nuttx.yahoogroups.narkive.com/3hggphCi/problem-related-semaphore-and-priority-inheritance
On Wed, Jan 5, 2022 at 2:22 PM Gregory Nutt <spudan...@gmail.com> wrote: > > 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. > > >
