Re: dma api errors with swiotlb

From: Thomas HellstrÃm (VMware)
Date: Wed Sep 04 2019 - 08:54:32 EST

On 9/4/19 2:17 PM, Christoph Hellwig wrote:
A call to dma_max_mapping_size() to limit the maximum I/O size solves
that problem. With the latest kernel that should actually be done
automatically by the SCSI midlayer for you.

Hmm, OK. I guess with a sufficient queue depth and many mappings waiting for DMA completion, the SWIOTLB may fill up anyway...

I'll see if I can come up with something.