----- Am 5. Sep 2019 um 7:25 schrieb Chris Johns chr...@rtems.org: > On 5/9/19 2:25 pm, Sebastian Huber wrote: >> ----- Am 4. Sep 2019 um 23:41 schrieb Chris Johns chr...@rtems.org: >> >>> On 5/9/19 2:09 am, Sebastian Huber wrote: >>>> Hello, >>>> >>>> I would like to wrap calls to interrupt handlers which use the generic >>>> interrupt >>>> framework (<rtems/irq-extension.h>) to get RTEMS_RECORD_INTERRUPT_ENTRY and >>>> RTEMS_RECORD_INTERRUPT_EXIT events. This cannot be done by the linker >>>> since the >>>> loop to call the handlers is inlined due to performance reasons. I would >>>> like >>>> to add some sort of a callback mechanism which is invoked in >>>> rtems_interrupt_handler_install() and rtems_interrupt_handler_remove() >>>> operations (similar to the user extensions). There are some options to do >>>> this. >>>> >>>> 1. A new linker set with functions. >>>> >>>> 2. A new user extension, maybe a generic: >>>> >>>> void (*event)(rtems_extension_event event, void *arg); >>>> >>>> 3. An API to install/remove a specific callback for this purpose. >>>> >>> >>> 4. Update or add a new API call to return the currently installed >>> handler. This way interrupts can be chained. >> >> This API already exists: >> >> https://docs.rtems.org/doxygen/branches/master/group__rtems__interrupt__extension.html#ga31d23275b676018c06e13c7bedc87983 >> >> The problem with this approach is that it doesn't wrap new handlers and if >> you >> remove a wrapped handler, then a memory leak or worse may happen. > > Yes care needs to be taken with this approach. > >> >>> >>>> I am in favour of 1. I also would like to hide it from the user for now. >>> >>> Does 1. allow runtime installing and then tracing of an interrupt? I know 3. >>> would. >> >> Yes, 1., 2., and 3. do the same, the difference is how you install the >> wrapper >> functionality and maybe how many you can install. > > It is difficult because you may want to trace one of a number of interrupt > sources or you may want to trigger tracing of another event due to system > issues.
For this complex scenario the proposed approach is not the right tool. To trace individual interrupts, you can wrap the specific interrupt handler and do your complex stuff. > >> >> 5. Use a weak function. >> > > Would this mean the overhead of the weak function happens all the time? I mean weak functions which are called during interrupt handler install/remove. The interrupt dispatching should remain as is with absolutely no overhead if recording is disabled. _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
