On Wed, 2020-06-24 at 03:24 -0300, Leonardo Bras wrote: > As of today, if a DDW is created and can't map the whole partition, it's > removed and the default DMA window "ibm,dma-window" is used instead. > > Usually this DDW is bigger than the default DMA window, so it would be > better to make use of it instead. > > Signed-off-by: Leonardo Bras <leobra...@gmail.com> > ---
I tested this change with a 256GB DDW which did not map the whole partition, with a MT27700 Family [ConnectX-4 Virtual Function]. I noticed the performance improvement is about the same as using DDW with IOMMU bypass. 64 thread write throughput: +203.0% 64 thread read throughput: +17.5% 1 thread write throughput: +20.5% 1 thread read throughput: +3.43% Averag e write latency: -23.0% Average read latency: -2.26%
