From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 66876A2EEB for ; Tue, 10 Sep 2019 15:56:05 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 870981EC86; Tue, 10 Sep 2019 15:56:04 +0200 (CEST) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by dpdk.org (Postfix) with ESMTP id 781D11EC21; Tue, 10 Sep 2019 15:56:03 +0200 (CEST) X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Sep 2019 06:56:02 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,489,1559545200"; d="scan'208";a="189350914" Received: from yexl-server.sh.intel.com (HELO localhost) ([10.67.117.5]) by orsmga006.jf.intel.com with ESMTP; 10 Sep 2019 06:56:00 -0700 Date: Tue, 10 Sep 2019 21:53:47 +0800 From: Ye Xiaolong To: "Zhang, Qi Z" Cc: "Yigit, Ferruh" , "Loftus, Ciara" , "dev@dpdk.org" , "stable@dpdk.org" , "Karlsson, Magnus" Message-ID: <20190910135347.GD6732@intel.com> References: <20190909161247.61801-1-xiaolong.ye@intel.com> <039ED4275CED7440929022BC67E7061153D93589@SHSMSX105.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <039ED4275CED7440929022BC67E7061153D93589@SHSMSX105.ccr.corp.intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) Subject: Re: [dpdk-dev] [PATCH] net/af_xdp: fix Tx halt when no recv packets X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list 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 09/10, Zhang, Qi Z wrote: > > >> -----Original Message----- >> From: Ye, Xiaolong >> Sent: Tuesday, September 10, 2019 12:13 AM >> To: Yigit, Ferruh ; Loftus, Ciara >> ; Ye, Xiaolong ; Zhang, Qi Z >> >> Cc: dev@dpdk.org; stable@dpdk.org >> Subject: [PATCH] net/af_xdp: fix Tx halt when no recv packets >> >> The kernel only consumes Tx packets if we have some Rx traffic on specified >> queue or we have called send(). So we need to issue a send() even when the >> allocation fails so that kernel will start to consume packets again. > >So "allocation fails" means " xsk_ring_prod__reserve" fail right? Yes. >I don't understand when xsk_ring_prod__needs_wakeup is true why kernel will stop Tx packet at this situation >would you share more insight? Actually, the fail case is xsk_ring_prod__needs_wakeup is false, then we can't issue a send() when xsk_ring_prod__reserve fails. Thanks, Xiaolong > >Thanks >Qi > >> >> Commit 45bba02c95b0 ("net/af_xdp: support need wakeup feature") breaks >> above rule by adding some condition to send, this patch fixes it while still >> keeps the need_wakeup feature for Tx. >> >> Fixes: 45bba02c95b0 ("net/af_xdp: support need wakeup feature") >> Cc: stable@dpdk.org >> >> Signed-off-by: Xiaolong Ye >> --- >> drivers/net/af_xdp/rte_eth_af_xdp.c | 28 ++++++++++++++-------------- >> 1 file changed, 14 insertions(+), 14 deletions(-) >> >> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c >> b/drivers/net/af_xdp/rte_eth_af_xdp.c >> index 41ed5b2af..e496e9aaa 100644 >> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c >> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c >> @@ -286,19 +286,16 @@ kick_tx(struct pkt_tx_queue *txq) { >> struct xsk_umem_info *umem = txq->pair->umem; >> >> -#if defined(XDP_USE_NEED_WAKEUP) >> - if (xsk_ring_prod__needs_wakeup(&txq->tx)) >> -#endif >> - while (send(xsk_socket__fd(txq->pair->xsk), NULL, >> - 0, MSG_DONTWAIT) < 0) { >> - /* some thing unexpected */ >> - if (errno != EBUSY && errno != EAGAIN && errno != EINTR) >> - break; >> - >> - /* pull from completion queue to leave more space */ >> - if (errno == EAGAIN) >> - pull_umem_cq(umem, ETH_AF_XDP_TX_BATCH_SIZE); >> - } >> + while (send(xsk_socket__fd(txq->pair->xsk), NULL, >> + 0, MSG_DONTWAIT) < 0) { >> + /* some thing unexpected */ >> + if (errno != EBUSY && errno != EAGAIN && errno != EINTR) >> + break; >> + >> + /* pull from completion queue to leave more space */ >> + if (errno == EAGAIN) >> + pull_umem_cq(umem, ETH_AF_XDP_TX_BATCH_SIZE); >> + } >> pull_umem_cq(umem, ETH_AF_XDP_TX_BATCH_SIZE); } >> >> @@ -367,7 +364,10 @@ eth_af_xdp_tx(void *queue, struct rte_mbuf >> **bufs, uint16_t nb_pkts) >> >> xsk_ring_prod__submit(&txq->tx, nb_pkts); >> >> - kick_tx(txq); >> +#if defined(XDP_USE_NEED_WAKEUP) >> + if (xsk_ring_prod__needs_wakeup(&txq->tx)) >> +#endif >> + kick_tx(txq); >> >> txq->stats.tx_pkts += nb_pkts; >> txq->stats.tx_bytes += tx_bytes; >> -- >> 2.17.1 >