On Fri, May 15, 2009 at 8:32 PM, Kanigeri, Hari <h-kanige...@ti.com> wrote: >> Do you know of any client that doing ReseveMemory and Map independently? >> How much overhead is there in ReserveMemory? >> What happens if the Map size is different than the ReserveMemory? What >> happens if the size is bigger? > > -- I cannot disclose the name, but it is some major Mobile Company that is > following this approach. One big chunk of DSP Virtual address region is > grabbed during boot time, and after that all the maps/unmaps are managed from > this memory region.
On Linux? So the DSP VA passed to Map would be v + chunk_size * i? >> How much overhead is there in ReserveMemory? > -- The overhead is the ioctls to the Bridge driver and the search that is > involved in searching for the DSP virtual address region that meets the size > requirement. Search a DSP virtual memory region from where? >> What happens if the Map size is different than the ReserveMemory? What >> happens if the size is bigger? > > -- The onus will be on the Client that reserved the memory to make sure that > the size to map is within the reserved memory block. Aha! Yet another place where the kernel is letting user-space screw up the system. >> In fact I don't even understand what is DSP VA memory. Is that virtual >> memory? > -- Yes, that is the DSP Virtual address. > >> What meaning is there on virtual memory that has no physical >> memory? > > -- The mapping to the physical address is done with the DSPProcessor_Map > function call. Yes, but before the Map function the virtual memory has no meaning. -- Felipe Contreras -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
