This was originally posted to the tools forum and it was pointed out that this is a better place for it.

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?