> On Wed, 2010-11-17 at 16:03 -0600, steven....@teradyne.com wrote: > > My application needs a fast way to access a specific physical DDR > > memory region. The application runs on an MPC8548 PowerPC which has an > > MMU. I've tried two approaches that are typical for Linux, mmap() and > > using a kernel module that implements read()/write() into this region > > and I'm finding that performance is very slow for both. It's a couple > > orders of magnitude slower than, for example, copying a large buffer > > from one place in the application's virtual memory to another place in > > the application's virtual memory. > > The mmap() version should basically run at "full speed", at least once > you've faulted the address range in. > > This specific DDR region isn't specifically slow is it ? :)
Or being mapped uncached ? David _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev