On Fri, May 15, 2015 at 7:41 AM, Sebastian Huber <sebastian.hu...@embedded-brains.de> wrote: > Aggregate several critical sections into a bigger one. Sending and > receiving messages is now protected by an ISR lock. Thread dispatching > is only disabled in case a blocking operation is necessary. The message > copy procedure is done inside the critical section (interrupts > disabled). Thus this change may have a negative impact on the interrupt > latency in case very large messages are transferred. > > Update #2273. > --- > diff --git a/doc/user/msg.t b/doc/user/msg.t > index f58d677..4ca5611 100644 > --- a/doc/user/msg.t > +++ b/doc/user/msg.t > @@ -50,7 +50,10 @@ wait for a message to arrive at a queue. Also, a task may > poll > a queue for the arrival of a message. > > The maximum length message which can be sent is set > -on a per message queue basis. > +on a per message queue basis. The message content must be copied in general > +to/from an internal buffer of the message queue or directly to a peer in > +certain cases. This copy operation is performed with interrupts disabled. > So > +it is advisible to keep the messages as short as possible. s/advisible/advisable
Thanks for making this note. Do we have any documentation that lists all the kinds of factors that affect the interrupt-disabled time? That would be "nice to have". _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
