Reducing RTEMS size to <32KB to fit in Epiphany local memories

[Sebastian Huber]

On 18/12/14 11:22, Hesham Moustafa wrote:
>> PS:
>> >
>> >The unlimited objects feature and the identifier to object translation in
>> >general are also a huge problem for SMP.
>> >
> Could you provide more details? I may work on this problem alongside
> some SMP locks implementation part of my research.

The _Objects_Get() obtains the Giant lock and then uses 
information->local_table[ index ] to get the object.  For fine grained 
locking have have to get the object without locks, but this is a problem 
since _Objects_Extend_information() allocates a new table and frees the 
old one.  There is a time frame in which we might access freed memory. 
One option is to disable interrupts before the information->local_table[ 
index ] since this would make the time frame very short.

A general question is whether the identifier to object translations 
should be completely dropped.

-- 
Sebastian Huber, embedded brains GmbH

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