RFC eliminating zeroing of heap/workspace

[Thomas Doerfler]

Joel Sherrill schrieb:
> Thomas Doerfler wrote:
> 
>> 2.) The behaviour of systems is a bit more repeatable when the memory is
>> set to a known state after boot
>>
>>   
> 
> Agreed and if this is the case, then the BSP certainly has the option of
> turning on the cpu_table.do_zero flag.
> 
>> These are not really striking arguments, so I am a bit torn between
>> zeroing memory or not. And no, I don't think this is worth another
>> general RTEMS configuration option :-)
>>
>>   
> 
> It already is. :)  I just changed the default in bspstart.c from TRUE to
> FALSE. :)

ok, wow, I really forgot about this. Switching it off by default seems
nice for me.
> 
>> wkr,
>> Thomas.
>>
>>  
>>
>>> On Apr 5, 2007, at 3:58 PM, Joel Sherrill wrote:
>>>
>>>
>>>    
>>>
>>>> Hi,
>>>>
>>>> I have done some investigation on a simulator
>>>> and determined that much of the time required
>>>> to bring the minimum test from reset to the
>>>> first task is consumed by zero'ing the
>>>> C Program Heap and RTEMS Workspace.
>>>>
>>>> My testing is on a simulated system which
>>>> has 4MB of RAM and zeroes all but maybe
>>>> 64K of it since that is the code and data.
>>>> It takes 97% of the boot time to clear this
>>>> much RAM.
>>>>
>>>> What's the general sentiment about clearing:
>>>>
>>>> + the C program heap
>>>> + the RTEMS workspace
>>>>
>>>> Just wanting opinions and thoughts.
>>>>
>>>> --joel
>>>> _______________________________________________
>>>> rtems-users mailing list
>>>> rtems-users at rtems.com
>>>> http://rtems.rtems.org/mailman/listinfo/rtems-users
>>>>       
>>>
>>>     
>>
>>
>>
>>   
> 
> 


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