On Thu, Aug 13, 2020 at 9:28 AM Richi Dubey <richidu...@gmail.com> wrote: > > Thanks, > > But I still can't find the code that links the 'Ready' in this > > >> #define RTEMS_SCHEDULER_EDF_SMP( name ) \ > >> static struct { \ > >> Scheduler_EDF_SMP_Context Base; \ This 'Base' will be an instance of the struct Scheduler_EDF_SMP_Context. In memory, it will look like this: Scheduler_EDF_SMP_Context Base = the 0-valued array won't actually take any storage.
> >> Scheduler_EDF_SMP_Ready_queue Ready[ CONFIGURE_MAXIMUM_PROCESSORS This > >> + 1 ]; \ > In memory this structure will look like this: { Scheduler_SMP_Context, int64_t, Chain_Control, Scheduler_EDF_SMP_Ready_queue[CONFIGURE_MAXIMUM_PROCESSORS + 1] } Because the Scheduler_EDF_SMP_Context type comes first and provides { Scheduler_SMP_Context, int64_t, Chain_Control, Scheduler_EDF_SMP_Ready_queue[0] } where the last element is a 0-value array so it doesn't actually take up any memory storage, then the Scheduler_EDF_SMP_Ready_queue Ready[ CONFIGURE_MAXIMUM_PROCESSORS + 1] overlaps with the Scheduler_EDF_SMP_Ready_queue[0] because the end of Base aligns with the start of Ready. This is what I meant by you need to review how C struct layout works. > to the 'Ready' in scheduleredfsmp.h: > > typedef struct { > Scheduler_SMP_Context Base; > > /** > * @brief Current generation for LIFO (index 0) and FIFO (index 1) ordering. > */ > int64_t generations[ 2 ]; > > /** > * @brief Chain of ready queues with affine threads to determine the highest > * priority ready thread. > */ > Chain_Control Affine_queues; > > /** > * @brief A table with ready queues. > * > * The index zero queue is used for threads with a one-to-all processor > * affinity. Index one corresponds to processor index zero, and so on. > */ > Scheduler_EDF_SMP_Ready_queue Ready[ RTEMS_ZERO_LENGTH_ARRAY ]; > } Scheduler_EDF_SMP_Context; > > If I figure this out, everything else would make sense too. Please help me > out. > > On Thu, Aug 13, 2020 at 8:47 PM Gedare Bloom <ged...@rtems.org> wrote: >> >> On Thu, Aug 13, 2020 at 8:34 AM Richi Dubey <richidu...@gmail.com> wrote: >> > >> > Thanks, >> > I am assuming this is the code that allocates space: >> > >> >> #define RTEMS_SCHEDULER_EDF_SMP( name ) \ >> >> static struct { \ >> >> Scheduler_EDF_SMP_Context Base; \ >> >> Scheduler_EDF_SMP_Ready_queue Ready[ CONFIGURE_MAXIMUM_PROCESSORS >> >> + 1 ]; \ >> >> } SCHEDULER_EDF_SMP_CONTEXT_NAME( name ) >> > >> This is declaring a structure type that will have a particular format >> of the struct name. >> >> > >> > How do we use or refer to this 'Base'? How do we link this 'Ready' to the >> > 'Ready' inside the EDF_SMP_Context? >> > >> >> This stuff gets set up during confdefs step. Eventually the scheduler >> contexts are instantiated in the scheduler table. >> >> confdefs/scheduler.h: >> #define CONFIGURE_SCHEDULER RTEMS_SCHEDULER_EDF_SMP( dflt ) >> >> #define CONFIGURE_SCHEDULER_TABLE_ENTRIES \ >> RTEMS_SCHEDULER_TABLE_EDF_SMP( dflt, CONFIGURE_SCHEDULER_NAME ) >> .... >> const Scheduler_Control _Scheduler_Table[] = { >> CONFIGURE_SCHEDULER_TABLE_ENTRIES >> }; >> >> This is where the space actually gets allocated, based on how >> CONFIGURE_SCHEDULER_TABLE_ENTRIES gets defined up to here from the CPP >> macros. >> >> >> >> > On Thu, Aug 13, 2020 at 6:17 PM Sebastian Huber >> > <sebastian.hu...@embedded-brains.de> wrote: >> > > >> > > On 13/08/2020 14:42, Richi Dubey wrote: >> > > >> > > > I want to use arrays with size _CONFIGURE_MAXIMUM_PROCESSORS. Is it >> > > > okay if I define the arrays with this size while writing the scheduler >> > > > strong APA header file? I am asking this because the value of this >> > > > header gets defined at the time the test case runs while the scheduler >> > > > gets linked to the test case at the time of linking. So how would it >> > > > work? >> > > >> > > Do NOT use _CONFIGURE_MAXIMUM_PROCESSORS. >> > > >> > > In <rtems/scheduler.h> please use something similar to the EDF scheduler >> > > instantiation: >> > > >> > > #ifdef CONFIGURE_SCHEDULER_EDF_SMP >> > > #include <rtems/score/scheduleredfsmp.h> >> > > >> > > #ifndef CONFIGURE_MAXIMUM_PROCESSORS >> > > #error "CONFIGURE_MAXIMUM_PROCESSORS must be defined to configure >> > > the EDF SMP scheduler" >> > > #endif >> > > >> > > #define SCHEDULER_EDF_SMP_CONTEXT_NAME( name ) \ >> > > SCHEDULER_CONTEXT_NAME( EDF_SMP_ ## name ) >> > > >> > > #define RTEMS_SCHEDULER_EDF_SMP( name ) \ >> > > static struct { \ >> > > Scheduler_EDF_SMP_Context Base; \ >> > > Scheduler_EDF_SMP_Ready_queue Ready[ CONFIGURE_MAXIMUM_PROCESSORS >> > > + 1 ]; \ >> > > } SCHEDULER_EDF_SMP_CONTEXT_NAME( name ) >> > > >> > > #define RTEMS_SCHEDULER_TABLE_EDF_SMP( name, obj_name ) \ >> > > { \ >> > > &SCHEDULER_EDF_SMP_CONTEXT_NAME( name ).Base.Base.Base, \ >> > > SCHEDULER_EDF_SMP_ENTRY_POINTS, \ >> > > SCHEDULER_EDF_MAXIMUM_PRIORITY, \ >> > > ( obj_name ) \ >> > > SCHEDULER_CONTROL_IS_NON_PREEMPT_MODE_SUPPORTED( false ) \ >> > > } >> > > >> > > /* Provided for backward compatibility */ >> > > >> > > #define RTEMS_SCHEDULER_CONTEXT_EDF_SMP( name, max_cpu_count ) \ >> > > RTEMS_SCHEDULER_EDF_SMP( name ) >> > > >> > > #define RTEMS_SCHEDULER_CONTROL_EDF_SMP( name, obj_name ) \ >> > > RTEMS_SCHEDULER_TABLE_EDF_SMP( name, obj_name ) >> > > #endif >> > > >> > _______________________________________________ >> > 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