Re: [PATCH v2 2/2] virtio-ring: Allocate indirect buffers from cache when possible

On Thu, Sep 06, 2012 at 05:27:23PM +0930, Rusty Russell wrote:

"Michael S. Tsirkin" [off-list ref] writes:

quoted

Yes without checksum net core always linearizes packets, so yes it is
screwed.
For -net, skb always allocates space for 17 frags + linear part so
it seems sane to do same in virtio core, and allocate, for -net,
up to max_frags + 1 from cache.
We can adjust it: no _SG -> 2 otherwise 18.

But I thought it used individual buffers these days?

Yes for receive, no for transmit. That's probably why
we should have the threshold per vq, not per device, BTW.

-- 
MST