Re: [virtio-comment] Re: [PATCH RESEND] virtio-net: support setting coalescing params for multiple vqs

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Dec 22, 2023 at 02:45:21PM +0800, Heng Qi wrote:
> > > For the current upstream code, the overhead is 256 kicks + 256*8 DMA times.
> > > The overhead of batch cmds is 1 kick + 256*8 DMA times.
> > This can furtherly optimized by using IN_ORDER. The DMA can be batched as well.
> 
> DMA batch reduces the number of DMA requests, but not the actual number of
> DMAs.
> For out DPU, how much to batch and when to end the batch also need to be
> evaluated in detail.

And what is the result of this evaluation? Again all this is slow path
stuff. Speed only matters if the operation takes many milliseconds.

-- 
MST