Re: [PATCH v5 0/2] skb_array: array based FIFO for skbs

[Jason Wang]

On 2016å05æ30æ 23:37, Michael S. Tsirkin wrote:
> On Mon, May 30, 2016 at 05:59:33PM +0800, Jason Wang wrote:
> > On 2016å05æ23æ 18:43, Michael S. Tsirkin wrote:
> > > 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.

> > 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?