From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 0B2441B10C; Thu, 1 Nov 2018 12:48:12 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 01 Nov 2018 04:48:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,451,1534834800"; d="scan'208";a="105088825" Received: from irsmsx107.ger.corp.intel.com ([163.33.3.99]) by orsmga002.jf.intel.com with ESMTP; 01 Nov 2018 04:48:10 -0700 Received: from irsmsx105.ger.corp.intel.com ([169.254.7.144]) by IRSMSX107.ger.corp.intel.com ([169.254.10.79]) with mapi id 14.03.0415.000; Thu, 1 Nov 2018 11:48:09 +0000 From: "Ananyev, Konstantin" To: "Xing, Beilei" , "Zhang, Qi Z" CC: "dev@dpdk.org" , "stable@dpdk.org" Thread-Topic: [dpdk-dev] [PATCH v3] net/i40e: fix Rx instability with vector mode Thread-Index: AQHUcacNrHPldvftD0iJeVI+q5RZVaU6ympg Date: Thu, 1 Nov 2018 11:48:09 +0000 Message-ID: <2601191342CEEE43887BDE71AB9772580103067496@irsmsx105.ger.corp.intel.com> References: <1540535607-115720-1-git-send-email-beilei.xing@intel.com> <1541051597-28949-1-git-send-email-beilei.xing@intel.com> In-Reply-To: <1541051597-28949-1-git-send-email-beilei.xing@intel.com> Accept-Language: en-IE, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiODdhZTQxMjItN2JiMi00ODlkLThmNjQtYThiY2UyMGM0NzBlIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjEwLjE4MDQuNDkiLCJUcnVzdGVkTGFiZWxIYXNoIjoidVc1XC9sZVZmUUNnNHArbTh0TjJ3dUpxanBKNUNPZ3dTTytQUlg2NDZSRzlPZ3hsZXZnU2hlNXVpK3VCd0J5dkEifQ== x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.0.400.15 dlp-reaction: no-action x-originating-ip: [163.33.239.182] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH v3] net/i40e: fix Rx instability with vector mode 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: , X-List-Received-Date: Thu, 01 Nov 2018 11:48:13 -0000 Hi >=20 > Previously, there is instability during vector Rx if descriptor > number is not power of 2, e.g. process hang and some Rx packets > are unexpectedly empty. That's because vector Rx mode assumes Rx > descriptor number is power of 2 when doing bit mask. > This patch allows vector mode only when the number of Rx descriptor > is power of 2. >=20 > Fixes: 8e109464c022 ("i40e: allow vector Rx and Tx usage") > Fixes: a3c83a2527e1 ("net/i40e: enable runtime queue setup") > Cc: stable@dpdk.org >=20 > Signed-off-by: Beilei Xing > --- > v3 changes: > - Add branch for non-first queue during runtime queue setup. > - Use function rte_is_power_of_2(). > - Configure rx_vec_allowed during setting Rx function. > v2 changes: > - rx_vec_allowed is global configuration, avoid overwrite. >=20 > doc/guides/nics/i40e.rst | 7 +++++++ > drivers/net/i40e/i40e_rxtx.c | 30 +++++++++++++++++++++++++++--- > 2 files changed, 34 insertions(+), 3 deletions(-) >=20 > diff --git a/doc/guides/nics/i40e.rst b/doc/guides/nics/i40e.rst > index ab3928a..bfacbd1 100644 > --- a/doc/guides/nics/i40e.rst > +++ b/doc/guides/nics/i40e.rst > @@ -172,6 +172,13 @@ Runtime Config Options >=20 > -w 84:00.0,use-latest-supported-vec=3D1 >=20 > +Vector RX Pre-conditions > +~~~~~~~~~~~~~~~~~~~~~~~~ > +For Vector RX it is assumed that the number of descriptor rings will be = a power > +of 2. With this pre-condition, the ring pointer can easily scroll back t= o the > +head after hitting the tail without a conditional check. In addition Vec= tor RX > +can use this assumption to do a bit mask using ``ring_size - 1``. > + > Driver compilation and testing > ------------------------------ >=20 > diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c > index a827456..771193a 100644 > --- a/drivers/net/i40e/i40e_rxtx.c > +++ b/drivers/net/i40e/i40e_rxtx.c > @@ -1735,12 +1735,21 @@ i40e_dev_rx_queue_setup_runtime(struct rte_eth_de= v *dev, > * i40e_set_rx_function. > */ > ad->rx_bulk_alloc_allowed =3D true; > - ad->rx_vec_allowed =3D true; > dev->data->scattered_rx =3D use_scattered_rx; > if (use_def_burst_func) > ad->rx_bulk_alloc_allowed =3D false; > + /** > + * Vector mode is allowed only when number of Rx queue > + * descriptor is a power of 2. > + */ > + ad->rx_vec_allowed =3D rte_is_power_of_2(rxq->nb_rx_desc); Actually do we need to do it here? We call set_rx_function() anyway, it would do that check for us, wouldn't i= t? > i40e_set_rx_function(dev); > return 0; > + } else if (ad->rx_vec_allowed && !rte_is_power_of_2(rxq->nb_rx_desc)) { > + PMD_DRV_LOG(ERR, "Vector mode is allowed, but descriptor" > + " number %d of queue %d isn't power of 2", > + rxq->nb_rx_desc, rxq->queue_id); > + return -EINVAL; > } >=20 > /* check bulk alloc conflict */ > @@ -2948,11 +2957,26 @@ i40e_set_rx_function(struct rte_eth_dev *dev) > { > struct i40e_adapter *ad =3D > I40E_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private); > + struct i40e_rx_queue *rxq; > uint16_t rx_using_sse, i; > + uint16_t desc; Please add empty line between var definitions and start of code. Helps readability. > /* In order to allow Vector Rx there are a few configuration > * conditions to be met and Rx Bulk Allocation should be allowed. > */ > if (rte_eal_process_type() =3D=3D RTE_PROC_PRIMARY) { > + if (!dev->data->dev_started) { > + for (i =3D 0; i < dev->data->nb_rx_queues; i++) { > + rxq =3D dev->data->rx_queues[i]; > + desc =3D rxq->nb_rx_desc; > + if (!i) > + ad->rx_vec_allowed =3D > + rte_is_power_of_2(desc); > + else if (ad->rx_vec_allowed && > + !rte_is_power_of_2(desc)) > + ad->rx_vec_allowed =3D false; Wouldn't be a bit cleaner: ad->rx_vec_allowed =3D (ad->rx_vec_allowed =3D=3D true) ? rte_is_power_of_2= (desc)) : ad->rx_vec_allowed; > + } > + } > + Probably better to move that code into i40e_rx_vec_dev_conf_condition_check= () that will be called on next line? > if (i40e_rx_vec_dev_conf_condition_check(dev) || > !ad->rx_bulk_alloc_allowed) { > PMD_INIT_LOG(DEBUG, "Port[%d] doesn't meet" > @@ -2961,10 +2985,10 @@ i40e_set_rx_function(struct rte_eth_dev *dev) >=20 > ad->rx_vec_allowed =3D false; > } > + > if (ad->rx_vec_allowed) { > for (i =3D 0; i < dev->data->nb_rx_queues; i++) { > - struct i40e_rx_queue *rxq =3D > - dev->data->rx_queues[i]; > + rxq =3D dev->data->rx_queues[i]; >=20 > if (rxq && i40e_rxq_vec_setup(rxq)) { > ad->rx_vec_allowed =3D false; > -- > 2.5.5