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[FreeRTOS Home] [Live FreeRTOS Forum] [FAQ] [Archive Top] [October 2012 Threads] Extra bytes in heapSTRUCT_SIZE?Posted by Tom Daugherty on October 9, 2012 Using v7.2.0, it looks like there are an extra 8 bytes added for every pvPortMalloc call due to the computation of heapSTRUCT_SIZE. This is true for heap_2 and heap_4. Currently,
static const unsigned short heapSTRUCT_SIZE= ( sizeof( xBlockLink ) + portBYTE_ALIGNMENT - ( sizeof( xBlockLink ) % portBYTE_ALIGNMENT ) );
and in my case of a Cortex-M4 and a Keil compiler, portBYTE_ALIGNMENT is 8, and sizeof(xBlockLink) is 8. This line of code results in a heapSTRUCT_SIZE of 16 when the actual structure size is already on an 8 byte boundary. Would it be better to do something like,
static const unsigned short heapSTRUCT_SIZE = (sizeof(xBlockLink) & portBYTE_ALIGNMENT_MASK)? (sizeof(xBlockLink) + (portBYTE_ALIGNMENT - (sizeof(xBlockLink) & portBYTE_ALIGNMENT_MASK))): (sizeof(xBlockLink));
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