> From: Kamalakshitha Aligeri [mailto:kamalakshitha.alig...@arm.com] > Sent: Wednesday, 5 July 2023 20.03 > > 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.alig...@arm.com> > Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com> > Reviewed-by: Feifei Wang <feifei.wa...@arm.com> > --- > drivers/net/i40e/i40e_rxtx_vec_common.h | 27 ++++++++++++++++++++----- > 1 file changed, 22 insertions(+), 5 deletions(-) > > diff --git a/drivers/net/i40e/i40e_rxtx_vec_common.h > b/drivers/net/i40e/i40e_rxtx_vec_common.h > index fe1a6ec75e..35cdb31b2e 100644 > --- a/drivers/net/i40e/i40e_rxtx_vec_common.h > +++ b/drivers/net/i40e/i40e_rxtx_vec_common.h > @@ -95,18 +95,35 @@ 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[i].mbuf; > /* no need to reset txep[i].mbuf in vector path */ > } > - 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);
Patchwork, when building with gcc-debug for FreeBSD13-64 and RHEL92-64, complains that "free" may be used uninitialized in rte_mempool_check_cookies() called via RTE_MEMPOOL_CHECK_COOKIES() from rte_mempool_generic_put() here. But "free" is initialized by the preceding loop, so I don't understand why GCC thinks it may be uninitialized. Does adding curly braces to the loop help GCC understand that the free array is initialized, or what is the proper workaround? > + goto done; > + > } > > m = rte_pktmbuf_prefree_seg(txep[0].mbuf); > -- > 2.25.1 Acked-by: Morten Brørup <m...@smartsharesystems.com>
