обзор очередей сообщений POSIX (overview of POSIX message queues)
Ошибки (баги) (Bugs)
In Linux versions 3.5 to 3.14, the kernel imposed a ceiling of
1024 (HARD_QUEUESMAX) on the value to which the queues_max limit
could be raised, and the ceiling was enforced even for privileged
processes. This ceiling value was removed in Linux 3.14, and
patches to stable kernels 3.5.x to 3.13.x also removed the
ceiling.
As originally implemented (and documented), the QSIZE field
displayed the total number of (user-supplied) bytes in all
messages in the message queue. Some changes in Linux 3.5
inadvertently changed the behavior, so that this field also
included a count of kernel overhead bytes used to store the
messages in the queue. This behavioral regression was rectified
in Linux 4.2 (and earlier stable kernel series), so that the
count once more included just the bytes of user data in messages
in the queue.
