From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id 0EC1DF94; Mon, 29 Oct 2018 02:48:36 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Oct 2018 18:48:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,438,1534834800"; d="scan'208";a="81658122" Received: from fmsmsx104.amr.corp.intel.com ([10.18.124.202]) by fmsmga007.fm.intel.com with ESMTP; 28 Oct 2018 18:48:35 -0700 Received: from fmsmsx155.amr.corp.intel.com (10.18.116.71) by fmsmsx104.amr.corp.intel.com (10.18.124.202) with Microsoft SMTP Server (TLS) id 14.3.408.0; Sun, 28 Oct 2018 18:48:35 -0700 Received: from shsmsx103.ccr.corp.intel.com (10.239.4.69) by FMSMSX155.amr.corp.intel.com (10.18.116.71) with Microsoft SMTP Server (TLS) id 14.3.408.0; Sun, 28 Oct 2018 18:48:34 -0700 Received: from shsmsx101.ccr.corp.intel.com ([169.254.1.102]) by SHSMSX103.ccr.corp.intel.com ([169.254.4.161]) with mapi id 14.03.0415.000; Mon, 29 Oct 2018 09:48:33 +0800 From: "Xing, Beilei" To: "Zhang, Qi Z" , "Ananyev, Konstantin" CC: "dev@dpdk.org" , "stable@dpdk.org" Thread-Topic: [dpdk-dev] [PATCH v2] net/i40e: fix Rx instability with vector mode Thread-Index: AQHUbPW1fPFUG9VcVESuhAu9fVdHPqUwsOUAgABz1wCABFIlAA== Date: Mon, 29 Oct 2018 01:48:31 +0000 Message-ID: <94479800C636CB44BD422CB454846E013CD0DFE0@SHSMSX101.ccr.corp.intel.com> References: <1540453252-128654-1-git-send-email-beilei.xing@intel.com> <1540535607-115720-1-git-send-email-beilei.xing@intel.com> <2601191342CEEE43887BDE71AB9772580102FED12C@IRSMSX106.ger.corp.intel.com> <039ED4275CED7440929022BC67E70611532DBD72@SHSMSX103.ccr.corp.intel.com> In-Reply-To: <039ED4275CED7440929022BC67E70611532DBD72@SHSMSX103.ccr.corp.intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiYjQxNzMwYWItZGViNS00NmVmLWI2ODYtNjMyODFlN2JiYzg0IiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjEwLjE4MDQuNDkiLCJUcnVzdGVkTGFiZWxIYXNoIjoiY2lXak9FdWhER0Q5dm0yXC9LMHRjQnhBcnAyYzBCNHBBQmk2ZHZPXC8xT3NrUDFTZVNTc3lmQTgzSkwzSFRVZlY5In0= x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.0.400.15 dlp-reaction: no-action x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH v2] 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: Mon, 29 Oct 2018 01:48:37 -0000 > -----Original Message----- > From: Zhang, Qi Z > Sent: Friday, October 26, 2018 11:42 PM > To: Ananyev, Konstantin ; Xing, Beilei > > Cc: dev@dpdk.org; stable@dpdk.org > Subject: RE: [dpdk-dev] [PATCH v2] net/i40e: fix Rx instability with vect= or > mode >=20 >=20 >=20 > > -----Original Message----- > > From: Ananyev, Konstantin > > Sent: Friday, October 26, 2018 3:47 AM > > To: Xing, Beilei ; Zhang, Qi Z > > > > Cc: dev@dpdk.org; stable@dpdk.org > > Subject: RE: [dpdk-dev] [PATCH v2] net/i40e: fix Rx instability with > > vector mode > > > > > > Hi, > > > > > > > > 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. > > > > > > Fixes: 8e109464c022 ("i40e: allow vector Rx and Tx usage") > > > Fixes: a3c83a2527e1 ("net/i40e: enable runtime queue setup") > > > Cc: stable@dpdk.org > > > > > > Signed-off-by: Beilei Xing > > > --- > > > > > > v2 changes: > > > - rx_vec_allowed is global configuration, avoid overwrite. > > > > > > doc/guides/nics/i40e.rst | 7 +++++++ > > > drivers/net/i40e/i40e_rxtx.c | 13 ++++++++++++- > > > 2 files changed, 19 insertions(+), 1 deletion(-) > > > > > > 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 > > > > > > -w 84:00.0,use-latest-supported-vec=3D1 > > > > > > +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 to the head after hitting the tail without a > > > +conditional check. In addition Vector RX can use this assumption to > > > +do a bit mask > > using ``ring_size - 1``. > > > + > > > Driver compilation and testing > > > ------------------------------ > > > > > > diff --git a/drivers/net/i40e/i40e_rxtx.c > > > b/drivers/net/i40e/i40e_rxtx.c index a827456..f6dcca0 100644 > > > --- a/drivers/net/i40e/i40e_rxtx.c > > > +++ b/drivers/net/i40e/i40e_rxtx.c > > > @@ -1735,10 +1735,14 @@ i40e_dev_rx_queue_setup_runtime(struct > > rte_eth_dev *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 !(rxq->nb_rx_desc & (rxq->nb_rx_desc - > 1)); > > > i40e_set_rx_function(dev); > > > return 0; > > > } > > > > I think this is not complete - if it is not the first function, we hav= e to do: > > If (if (ad->rx_vec_allowed && (rxq->nb_rx_desc & (rxq->nb_rx_desc - 1) > > !=3D 0) { > > PMD_DRV_LOG(ERR, ...); > > return -EINVAL; > > } >=20 > Yes, we should prevent downgrade if the device is already running. OK, will update in next version. >=20 > > > > BTW, here and below why not to use rte_is_power_of_2()? Thanks for the reminder, will use the inline function in next version. > > Konstantin > > > > > @@ -1811,6 +1815,13 @@ i40e_dev_rx_queue_setup(struct > rte_eth_dev > > *dev, > > > return -EINVAL; > > > } > > > > > > + /** > > > + * Vector mode is allowed only when number of Rx queue > > > + * descriptor is a power of 2. > > > + */ > > > + if (ad->rx_vec_allowed) > > > + ad->rx_vec_allowed =3D !(nb_desc & (nb_desc - 1)); >=20 > Looks like we are not able to get back to vec mode once some queue is set > to no power of 2, even if all queues has been re-setup to power of 2 agai= n. > Seems we still need to check all other queue's configure here. We can allow vector again when runtime configuring the first queue whose de= scriptor number is power of 2, right? >=20 > > > + > > > /* Free memory if needed */ > > > if (dev->data->rx_queues[queue_idx]) { > > > > i40e_dev_rx_queue_release(dev->data->rx_queues[queue_idx]); > > > > > > > > > > > >