On Mon, May 30, 2016 at 05:59:33PM +0800, Jason Wang wrote: > > > On 2016年05月23日 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? > 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? -- MST
