On Fri, Sep 7, 2018 at 9:48 AM, Sebastian Huber <sebastian.hu...@embedded-brains.de> wrote: > Close #3508. > --- > c-user/symmetric_multiprocessing_services.rst | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/c-user/symmetric_multiprocessing_services.rst > b/c-user/symmetric_multiprocessing_services.rst > index 4204d3f..4c80cb9 100644 > --- a/c-user/symmetric_multiprocessing_services.rst > +++ b/c-user/symmetric_multiprocessing_services.rst > @@ -809,3 +809,21 @@ RTMES provides two means for per-processor data: > `<rtems/score/percpudata.h> > <https://git.rtems.org/rtems/tree/cpukit/include/rtems/score/percpudata.h>`_. > This API is not intended for general application use. Please ask on the > development mailing list in case you want to use it. > + > +Thread Pinning > +-------------- > + This is fine, but I think a single sentence to briefly just explain what pinning is could be helpful at the start of this section, like: "Thread pinning ensures that a thread is only dispatched to the processor on which it is pinned."
> +Thread pinning may be used to access per-processor data structures in > critical > +sections with enabled thread dispatching, e.g. a pinned thread is allowed to > +block. The `_Thread_Pin()` operation will pin the executing thread to its > +current processor. A thread may be pinned recursively, the last unpin > request > +via `_Thread_Unpin()` revokes the pinning. > + > +Thread pinning should be used only for short critical sections and not all > +the time. Thread pinning is a very low overhead operation in case the > +thread is not preempted during the pinning. A preemption will result in > +scheduler operations to ensure that the thread executes only on its pinned > +processor. Thread pinning must be used with care, since it prevents help > +through the locking protocols. This makes the :ref:`OMIP <OMIP>` and > +:ref:`MrsP <MrsP>` locking protocols ineffective if pinned threads are > +involved. > -- > 2.13.7 > > _______________________________________________ > devel mailing list > devel@rtems.org > http://lists.rtems.org/mailman/listinfo/devel _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
