Optimization issue in RISC-V BSP

Joel Sherrill joel at rtems.org
Sat Jul 29 01:45:50 UTC 2017


On Jul 28, 2017 7:11 PM, "Denis Obrezkov" <denisobrezkov at gmail.com> wrote:

2017-07-29 1:41 GMT+02:00 Joel Sherrill <joel at rtems.org>:

>
>
> On Jul 28, 2017 6:39 PM, "Denis Obrezkov" <denisobrezkov at gmail.com> wrote:
>
> 2017-07-29 1:28 GMT+02:00 Joel Sherrill <joel at rtems.org>:
>
>>
>>
>> On Jul 28, 2017 6:14 PM, "Denis Obrezkov" <denisobrezkov at gmail.com>
>> wrote:
>>
>> 2017-07-29 0:57 GMT+02:00 Joel Sherrill <joel at rtems.org>:
>>
>>>
>>>
>>> On Jul 28, 2017 5:55 PM, "Denis Obrezkov" <denisobrezkov at gmail.com>
>>> wrote:
>>>
>>> 2017-07-28 22:36 GMT+02:00 Joel Sherrill <joel at rtems.org>:
>>>
>>>> Can you check the memory immediately after a download'?
>>>>
>>>> Then after the loop that copies initialized data into place?
>>>>
>>>> I suspect something off there. Could be a linker script issue or the
>>>> copy gone crazy.
>>>>
>>>> --joel
>>>>
>>>> On Fri, Jul 28, 2017 at 3:20 PM, Denis Obrezkov <
>>>> denisobrezkov at gmail.com> wrote:
>>>>
>>>>> 2017-07-28 22:16 GMT+02:00 Joel Sherrill <joel at rtems.org>:
>>>>>
>>>>>>
>>>>>>
>>>>>> On Fri, Jul 28, 2017 at 2:50 PM, Denis Obrezkov <
>>>>>> denisobrezkov at gmail.com> wrote:
>>>>>>
>>>>>>>
>>>>>>>>> I can see that during task initialization I have a call:
>>>>>>>>>  _Thread_Initialize_information (information=information at entry=0x80000ad4
>>>>>>>>> <_RTEMS_tasks_Information>, the_api=the_api at entry=OBJECTS_CLASSIC_API,
>>>>>>>>> the_class=the_class at entry=1, maximum=124,
>>>>>>>>>     is_string=is_string at entry=false,
>>>>>>>>> maximum_name_length=maximum_name_length at entry=4)
>>>>>>>>>
>>>>>>>>> And maximum is 124, but I have a configuration parameter:
>>>>>>>>> #define CONFIGURE_MAXIMUM_TASKS             4
>>>>>>>>>
>>>>>>>>
>>>>>>>> I can't imagine any standard RTEMS test configuring that many
>>>>>>>> tasks.
>>>>>>>> Is there a data corruption issue?
>>>>>>>>
>>>>>>>> 124 = 0x7c which doesn't ring any bells for me on odd memory issues.
>>>>>>>>
>>>>>>>> What is the contents of "Configuration_RTEMS_API"?
>>>>>>>>
>>>>>>> Oh, I change my configuration options a bit, they are:
>>>>>>>   #define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER
>>>>>>>   #define CONFIGURE_APPLICATION_DISABLE_FILESYSTEM
>>>>>>>   #define CONFIGURE_DISABLE_NEWLIB_REENTRANCY
>>>>>>>   #define CONFIGURE_TERMIOS_DISABLED
>>>>>>>   #define CONFIGURE_LIBIO_MAXIMUM_FILE_DESCRIPTORS 0
>>>>>>>   #define CONFIGURE_MINIMUM_TASK_STACK_SIZE 512
>>>>>>>   #define CONFIGURE_MAXIMUM_PRIORITY 3
>>>>>>>   #define CONFIGURE_DISABLE_CLASSIC_API_NOTEPADS
>>>>>>>   #define CONFIGURE_IDLE_TASK_BODY Init
>>>>>>>   #define CONFIGURE_IDLE_TASK_INITIALIZES_APPLICATION
>>>>>>>   #define CONFIGURE_TASKS 4
>>>>>>>
>>>>>>>   #define CONFIGURE_MAXIMUM_TASKS             4
>>>>>>>
>>>>>>>   #define CONFIGURE_UNIFIED_WORK_AREAS
>>>>>>>
>>>>>>> Also it is the test from a lower ticker example.
>>>>>>> Configuration_RTEMS_API with -O0 option:
>>>>>>> {maximum_tasks = 5, maximum_timers = 0, maximum_semaphores = 7,
>>>>>>> maximum_message_queues = 0, maximum_partitions = 0, maximum_regions = 0,
>>>>>>> maximum_ports = 0, maximum_periods = 0,
>>>>>>>   maximum_barriers = 0, number_of_initialization_tasks = 0,
>>>>>>> User_initialization_tasks_table = 0x0}
>>>>>>>
>>>>>>> with -Os option:
>>>>>>> {maximum_tasks = 124, maximum_timers = 0, maximum_semaphores = 7,
>>>>>>> maximum_message_queues = 0, maximum_partitions = 0, maximum_regions = 0,
>>>>>>> maximum_ports = 0, maximum_periods = 0,
>>>>>>>   maximum_barriers = 0, number_of_initialization_tasks = 0,
>>>>>>> User_initialization_tasks_table = 0x0}
>>>>>>>
>>>>>>
>>>>>> Hmmm.. If you look at this structure in gdb without attaching to the
>>>>>> target, what
>>>>>> is maximum_tasks?
>>>>>>
>>>>>> --joel
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>>>
>>>>>>>>> It seems that other tasks are LIBBLOCK tasks.
>>>>>>>>>
>>>>>>>>> Also, this is my Configuration during run:
>>>>>>>>> (gdb) p Configuration.stack_space_size
>>>>>>>>> $1 = 2648
>>>>>>>>> (gdb) p Configuration.work_space_size
>>>>>>>>> $2 = 4216
>>>>>>>>> (gdb) p Configuration.interrupt_stack_size
>>>>>>>>> $3 = 512
>>>>>>>>> (gdb) p Configuration.idle_task_stack_size
>>>>>>>>> $4 = 512
>>>>>>>>>
>>>>>>>>
>>>>>>>> That looks reasonable. Add CONFIGURE_MAXIMUM_PRIORITY and set it to
>>>>>>>> 4. That should
>>>>>>>> reduce the workspace.
>>>>>>>>
>>>>>>>>  long term, we might want to consider lowering it permanently like
>>>>>>>> one of the Coldfires
>>>>>>>> had to. Or change the default scheduler to the Simple one to save
>>>>>>>> memory.
>>>>>>>>
>>>>>>>>
>>>>>>> I haven't dealt with the Scheduler option yet.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Regards, Denis Obrezkov
>>>>>>>
>>>>>>
>>>>>> maximum_tasks = 4
>>>>> So, is it a linker file issue?
>>>>>
>>>>> This is it:
>>>>> https://github.com/embeddedden/rtems-riscv/blob/hifive1/c/sr
>>>>> c/lib/libbsp/riscv32/hifive1/startup/linkcmds
>>>>>
>>>>> --
>>>>> Regards, Denis Obrezkov
>>>>>
>>>>
>>>> After download:
>>> {maximum_tasks = 938162044, maximum_timers = 1270834941,
>>> maximum_semaphores = 2534801264 <(253)%20480-1264>,
>>> maximum_message_queues = 425684620, maximum_partitions = 1496738036,
>>>   maximum_regions = 3085560870 <(308)%20556-0870>, maximum_ports =
>>> 4269782132, maximum_periods = 2362012542 <(236)%20201-2542>,
>>> maximum_barriers = 1138223297, number_of_initialization_tasks = 4224313421,
>>>   User_initialization_tasks_table = 0x43bd1bd3}
>>>
>>> right after data copying:
>>> {maximum_tasks = 124, maximum_timers = 0, maximum_semaphores = 1,
>>> maximum_message_queues = 0, maximum_partitions = 0, maximum_regions = 0,
>>> maximum_ports = 0, maximum_periods = 0,
>>>   maximum_barriers = 0, number_of_initialization_tasks = 0,
>>> User_initialization_tasks_table = 0x0}
>>>
>>> But I found the mistake - I made it in .data initialization code
>>> (https://github.com/embeddedden/rtems-riscv/blob/hifive1/c/s
>>> rc/lib/libbsp/riscv32/hifive1/start/start.S#L116 - first byte in the
>>> loop was uninitialized)
>>>
>>>
>>> Awesome! Does that mean it is running?
>>>
>>>
>>>
>>> --
>>> Regards, Denis Obrezkov
>>>
>>>
>>> Yes, it is running now. Not far, but running.
>> Now I am having an exception during atexit( Clock_exit )
>>
>>
>> Does it get to bsp_cleanup and bsp_reset? Are you seeing the Terminate?
>>
>> I think those are the names. Basically some BSPs deliberately throw an
>> exception as the way to end.
>>
>>
>>
>>
>>
>> --
>> Regards, Denis Obrezkov
>>
>>
>> Unfortunately, I have an exception in the beginning during clock driver
> initialization around this line:
> 0x204053a0      80      in ../../../../../gcc-7.1.0/newli
> b/libc/stdlib/__atexit.c
>
>
> No obvious suggestions from me right now except to debug.
>
>
>
>
>
> --
> Regards, Denis Obrezkov
>
>
> Is it possible that newlib has a wrong linker file? That a variable placed
out of the rtems-linkcmd-defined bounds?


I don't think so. Look at the atexit source and see what it assume is
initialized




-- 
Regards, Denis Obrezkov
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.rtems.org/pipermail/devel/attachments/20170728/ff53994f/attachment-0002.html>


More information about the devel mailing list