[rds-devel] [PATCH net-next v2] net/rds: Use DMA memory pool allocation for rds_header

[David Miller]

From: Ka-Cheong Poon <ka-cheong.poon at oracle.com>
Date: Wed,  2 Oct 2019 21:11:08 -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.  The DMA addresses of the pre-
> allocated headers are stored in an array.  At send/receive ring
> initialization and refill time, this arrary is de-referenced to get
> the DMA addresses.  This array is not accessed at send/receive packet
> processing.
> 
> Suggested-by: Håkon Bugge <haakon.bugge at oracle.com>
> Signed-off-by: Ka-Cheong Poon <ka-cheong.poon at oracle.com>
> Acked-by: Santosh Shilimkar <santosh.shilimkar at oracle.com>

Applied.