From: Ka-Cheong Poon <ka-cheong.p...@oracle.com> Date: Mon, 30 Sep 2019 02:08:00 -0700
> Currently, RDS calls ib_dma_alloc_coherent() to allocate a large piece > of contiguous DMA coherent memory to store struct rds_header for > sending/receiving packets. The memory allocated is then partitioned > into struct rds_header. This is not necessary and can be costly at > times when memory is fragmented. Instead, RDS should use the DMA > memory pool interface to handle this. > > Suggested-by: Håkon Bugge <haakon.bu...@oracle.com> > Signed-off-by: Ka-Cheong Poon <ka-cheong.p...@oracle.com> This is trading a one-time overhead for extra levels of dereferencing on every single descriptor access in the fast paths. I do not agree with this tradeoff, please implement this more reasonably.
