From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yongseok Koh Subject: Re: [PATCH 2/5] net/mlx5: free buffers in bulk on Tx completion Date: Fri, 30 Jun 2017 10:49:56 -0700 Message-ID: <20170630174956.GA911@yongseok-MBP.local> References: <20170628230403.10142-1-yskoh@mellanox.com> <20170628230403.10142-3-yskoh@mellanox.com> <20170630123047.GO18305@autoinstall.dev.6wind.com> <20170630124321.GP18305@autoinstall.dev.6wind.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Cc: ferruh.yigit@intel.com, dev@dpdk.org, adrien.mazarguil@6wind.com To: =?iso-8859-1?Q?N=E9lio?= Laranjeiro Return-path: Received: from EUR03-DB5-obe.outbound.protection.outlook.com (mail-eopbgr40070.outbound.protection.outlook.com [40.107.4.70]) by dpdk.org (Postfix) with ESMTP id 55771377A for ; Fri, 30 Jun 2017 19:50:12 +0200 (CEST) Content-Disposition: inline In-Reply-To: <20170630124321.GP18305@autoinstall.dev.6wind.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Fri, Jun 30, 2017 at 02:43:21PM +0200, Nélio Laranjeiro wrote: > On Fri, Jun 30, 2017 at 02:30:47PM +0200, Nélio Laranjeiro wrote: > > On Wed, Jun 28, 2017 at 04:04:00PM -0700, Yongseok Koh wrote: > > > When processing Tx completion, it is more efficient to free buffers in bulk > > > using rte_mempool_put_bulk() if buffers are from a same mempool. > > > > > > Signed-off-by: Yongseok Koh > > > --- > > > drivers/net/mlx5/mlx5_rxtx.c | 36 +++++++++++++++++++++++++++--------- > > > 1 file changed, 27 insertions(+), 9 deletions(-) > > > > > > diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c > > > index 43db06ad8..d81d630f7 100644 > > > --- a/drivers/net/mlx5/mlx5_rxtx.c > > > +++ b/drivers/net/mlx5/mlx5_rxtx.c > > > @@ -264,6 +264,8 @@ txq_complete(struct txq *txq) > > > uint16_t cq_ci = txq->cq_ci; > > > volatile struct mlx5_cqe *cqe = NULL; > > > volatile struct mlx5_wqe_ctrl *ctrl; > > > + struct rte_mbuf *m, *free[elts_n]; > > > + unsigned int blk_n = 0; > > > > > > do { > > > volatile struct mlx5_cqe *tmp; > > > @@ -296,21 +298,37 @@ txq_complete(struct txq *txq) > > > assert((elts_tail & elts_m) < (1 << txq->wqe_n)); > > > /* Free buffers. */ > > > while (elts_free != elts_tail) { > > > - struct rte_mbuf *elt = (*txq->elts)[elts_free & elts_m]; > > > - struct rte_mbuf *elt_next = > > > - (*txq->elts)[(elts_free + 1) & elts_m]; > > > - > > > + m = rte_pktmbuf_prefree_seg((*txq->elts)[elts_free++ & elts_m]); > > > + if (likely(m != NULL)) { > > > + if (blk_n) { > > > + if (likely(m->pool == free[0]->pool)) { > > > + free[blk_n++] = m; > > > + } else { > > > + rte_mempool_put_bulk( > > > + free[0]->pool, > > > + (void *)free, > > > + blk_n); > > > > The indentation is strange here, free[0] should be on the same line as > > rte_mempool_put_bulk. > > > > > + free[0] = m; > > > + blk_n = 1; > > > + } > > > + } else { > > > + free[0] = m; > > > + blk_n = 1; > > > + } > > > + } > > > > This loop could be smaller, blk_n can only be equal to 0 in the first > > iteration, otherwise is >= 1. > > The first if statement can be merged with the second one: > > > > if (likely(m != NULL)) { > > if (likely(blk_n && m->pool == free[0]->pool)) { > > This condition is a wrong also, it should be !blk_n || (m->pool ... > > Why don't you keep a pointer to the mpool (e.g. m->pool == pool)? It > seems to cost a little to deference two pointers to reach the pool's > one. Good point. The following will be the final streamlined code. /* Free buffers. */ while (elts_free != elts_tail) { m = rte_pktmbuf_prefree_seg((*txq->elts)[elts_free++ & elts_m]); if (likely(m != NULL)) { if (likely(m->pool == pool)) { free[blk_n++] = m; } else { if (likely(pool != NULL)) rte_mempool_put_bulk(pool, (void *)free, blk_n); free[0] = m; pool = m->pool; blk_n = 1; } } } if (blk_n) rte_mempool_put_bulk(pool, (void *)free, blk_n); Thanks, Yongseok