RE: [PATCH v2 1/2] net/i40e: replace put function

[Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>]

<snip>
[
> 
> > From: Kamalakshitha Aligeri [mailto:kamalakshitha.aligeri@arm.com]
> > Sent: Friday, 10 February 2023 07.54
> >
> > Integrated zero-copy put API in mempool cache in i40e PMD.
> > On Ampere Altra server, l3fwd single core's performance improves by 5%
> > with the new API
> >
> > Signed-off-by: Kamalakshitha Aligeri <kamalakshitha.aligeri@arm.com>
> > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> > Reviewed-by: Feifei Wang <feifei.wang2@arm.com>
> > ---
> > Link:
> > https://patchwork.dpdk.org/project/dpdk/patch/20230209145833.129986-1-
> > mb@smartsharesystems.com/
> 
> If you agree with the referred patch, please review or acknowledge it on the
> mailing list, so it can be merged.
> 
> >
> >  .mailmap                                |  1 +
> >  drivers/net/i40e/i40e_rxtx_vec_common.h | 28
> > ++++++++++++++++++++-----
> >  2 files changed, 24 insertions(+), 5 deletions(-)
> >
> > diff --git a/.mailmap b/.mailmap
> > index 75884b6fe2..05a42edbcf 100644
> > --- a/.mailmap
> > +++ b/.mailmap
> > @@ -670,6 +670,7 @@ Kai Ji <kai.ji@intel.com>  Kaiwen Deng
> > <kaiwenx.deng@intel.com>  Kalesh AP
> > <kalesh-anakkur.purayil@broadcom.com>
> >  Kamalakannan R <kamalakannan.r@intel.com>
> > +Kamalakshitha Aligeri <kamalakshitha.aligeri@arm.com>
> >  Kamil Bednarczyk <kamil.bednarczyk@intel.com>  Kamil Chalupnik
> > <kamilx.chalupnik@intel.com>  Kamil Rytarowski
> > <kamil.rytarowski@caviumnetworks.com>
> > diff --git a/drivers/net/i40e/i40e_rxtx_vec_common.h
> > b/drivers/net/i40e/i40e_rxtx_vec_common.h
> > index fe1a6ec75e..113599d82b 100644
> > --- a/drivers/net/i40e/i40e_rxtx_vec_common.h
> > +++ b/drivers/net/i40e/i40e_rxtx_vec_common.h
> > @@ -95,18 +95,36 @@ i40e_tx_free_bufs(struct i40e_tx_queue *txq)
> >
> >  	n = txq->tx_rs_thresh;
> >
> > -	 /* first buffer to free from S/W ring is at index
> > -	  * tx_next_dd - (tx_rs_thresh-1)
> > -	  */
> > +	/* first buffer to free from S/W ring is at index
> > +	 * tx_next_dd - (tx_rs_thresh-1)
> > +	 */
> >  	txep = &txq->sw_ring[txq->tx_next_dd - (n - 1)];
> >
> >  	if (txq->offloads & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE) {
> > +		struct rte_mempool *mp = txep[0].mbuf->pool;
> > +		struct rte_mempool_cache *cache =
> > rte_mempool_default_cache(mp, rte_lcore_id());
> > +		void **cache_objs;
> > +
> > +		if (unlikely(!cache))
> > +			goto fallback;
> > +
> > +		cache_objs = rte_mempool_cache_zc_put_bulk(cache, mp, n);
> > +		if (unlikely(!cache_objs))
> > +			goto fallback;
> > +
> >  		for (i = 0; i < n; i++) {
> > -			free[i] = txep[i].mbuf;
> > +			cache_objs[i] = txep->mbuf;
> >  			/* no need to reset txep[i].mbuf in vector path */
> > +			txep++;
> 
> Why the change from "xyz[i] = txep[i].mbuf;" to "xyz[i] = txep->mbuf; txep++;"? I
> don't see "txep" being used after the "done" label. And at the fallback, you still
> use "xyz[i] = txep[i].mbuf;". It would look cleaner using the same method in
> both places.
+1

> 
> It's not important, so feel free to keep as is or change as suggested. Both ways,
> 
> Acked-by: Morten Brørup <mb@smartsharesystems.com>
> 
> >  		}
> > -		rte_mempool_put_bulk(free[0]->pool, (void **)free, n);
> >  		goto done;
> > +
> > +fallback:
> > +		for (i = 0; i < n; i++)
> > +			free[i] = txep[i].mbuf;
> > +		rte_mempool_generic_put(mp, (void **)free, n, cache);
> > +		goto done;
> > +
> >  	}
> >
> >  	m = rte_pktmbuf_prefree_seg(txep[0].mbuf);
> > --
> > 2.25.1
> >