On 2016年05月30日 23:37, Michael S. Tsirkin wrote:

On Mon, May 30, 2016 at 05:59:33PM +0800, Jason Wang wrote:

quoted

On 2016年05月23日 18:43, Michael S. Tsirkin wrote:

quoted

This is in response to the proposal by Jason to make tun
rx packet queue lockless using a circular buffer.
My testing seems to show that at least for the common usecase
in networking, which isn't lockless, circular buffer
with indices does not perform that well, because
each index access causes a cache line to bounce between
CPUs, and index access causes stalls due to the dependency.

I change tun to use skb array, looks like it can give about 5% more faster
than skb ring.

OK and skb ring is 9% faster than the linked list, so together
this is a 14% speedup?

Right.

quoted

And we usually don't need touch bhs during consume and produce (e.g for the
case of tun).

Thanks

Maybe I'll drop it in v6 then ...
Could you post the full tun patchset please?

Since it needs no bh versions of produce/consume, maybe you can post v6 
first, then I can post the tun patches?