Ken Schumm wrote:
> We're trying to optimize performance of our pxa270 product.
> 
> Towards that end we want to map in a region of the processors internal on-chip SRAM as shared memory.
> 
> When using SHMCTL_PHYS|SHMCTL_GLOBAL flags, shm_ctl() returns errno 89 (Function not implemented).
> 
> If we leave off the SHMCTL_GLOBAL then the code works but we need to map it GLOBAL to prevent the cache flush on 
context switch slowdown that occurs with this cache design.
> 
> The docs indicate this should be possible.
> 
> Anyone know anything about this?


I think you will get a better/faster response to your question if you post it to OSTech forum. 

If you're just trying to access physical memory, how about trying mmap instead?