On Fri, Mar 23, 2018 at 05:00:34PM +0000, Bruce Richardson wrote: > On Wed, Mar 21, 2018 at 09:04:01AM -0400, Neil Horman wrote: > > On Tue, Mar 20, 2018 at 04:34:04PM +0000, Ferruh Yigit wrote: > > > "struct rte_eth_rxtx_callback" is defined as internal data structure and > > > used as named opaque type. > > > > > > So the functions that are adding callbacks can return objects in this > > > type instead of void pointer. > > > > > > Also const qualifier added to "struct rte_eth_rxtx_callback *" to > > > protect it better from application modification. > > > > > > Signed-off-by: Ferruh Yigit <ferruh.yi...@intel.com> > > > --- > > > v2: > > > * keep using struct * in parameters, instead add callback functions > > > return struct rte_eth_rxtx_callback pointer. > > > > > > v4: > > > * Remove deprecation notice. LIBABIVER already increased in this release > > > > > > v5: > > > * add const qualifier to rte_eth_rxtx_callback > > I still wish we could find a way to remove the inline functions and truly > > protect that struct, but a const is definately better than nothing > > > > Acked-by: Neil Horman <nhor...@tuxdriver.com> > > > Actually, I think we should do exactly that - convert the rx and tx burst > calls into actual function calls (and consider any other inlined functions > too). The cost would be the overhead of making an additional function call > per-burst, which is likely to be pretty minimal for most common burst sizes > e.g. 32. > > We did some quick tests here with the i40e driver, and for a burst size of > 32 saw less than 1% perf drop, and for even a small burst of 8 saw less > than 5% drop. Note that this is testing with testpmd, which has nothing but > I/O in the datapath. A real-world app is likely to do far more with the > packets and therefore see proportionally far less perf hit. > > Thoughts? > > /Bruce > > PS: This un-inlining could probably be applied to other device types too, > e.g. cryptodev (though probably not eventdev as it tends to have smaller > bursts in some use-cases). > I would be 1000% on board with this conversion.
Best Neil
