Re: [PATCH net-next v2 3/4] virtio-net: auto-tune mergeable rx buffer size for improved performance
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2014-01-09 06:48:07
Also in:
netdev
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2014-01-09 06:48:07
Also in:
netdev
On Wed, Jan 08, 2014 at 07:41:58PM -0800, Michael Dalton wrote:
Sorry, forgot to mention - if we want to explore combining the buffer address and truesize into a single void *, we could also exploit the fact that our size ranges from aligned GOOD_PACKET_LEN to PAGE_SIZE, and potentially encode fewer values for truesize (and require a smaller alignment than 256). The prior e-mails discussion of 256 byte alignment with 256 values is just one potential design point. Best, Mike
Good point. I think we should keep the option to make buffers bigger than 4K, so I think we should start with 256 alignment, then see if there are workloads that are improved by smaller alignment. Can you add wrapper inline functions to pack/unpack size and buffer pointer to/from void *? This way it will be easy to experiment with different alignments.