On Wed, Jul 08, 2015 at 04:28:19PM +0200, Thomas Petazzoni wrote: > Due to how async_tx behaves internally, having more XOR channels than > CPUs is actually hurting performance more than it improves it, because > memcpy requests get scheduled on a different channel than the XOR > requests, but async_tx will still wait for the completion of the > memcpy requests before scheduling the XOR requests. > > It is in fact more efficient to have at most one channel per CPU, > which this patch implements by limiting the number of channels per > engine, and the number of engines registered depending on the number > of availables CPUs. > > Marvell platforms are currently available in one CPU, two CPUs and > four CPUs configurations: > > - in the configurations with one CPU, only one channel from one > engine is used. > > - in the configurations with two CPUs, only one channel from each > engine is used (they are two XOR engines) > > - in the configurations with four CPUs, both channels of both engines > are used. Applied, thanks -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
