Hi, Recently, I experienced a problem on scaterlist DMA mappping. It is said that if mapping 128KB data length for DMA tranfer, when I enable jbd2, dma_map_sg_attrs() will take more thant two times of time, comparing to the condition which jbd2 disabled. Somebody suggested me to print out DMA entry to look at what happening. I studied dma_map_sg_attrs() funciton a little bit, But don't much clear how to print this kind of info. Is there anyone who knows this? Thanks. //Bean
