From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755655Ab3LSShF (ORCPT ); Thu, 19 Dec 2013 13:37:05 -0500 Received: from na01-by1-obe.ptr.o365filtering.com ([64.4.22.90]:14282 "EHLO na01-by1-obe.outbound.o365filtering.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754636Ab3LSShB (ORCPT ); Thu, 19 Dec 2013 13:37:01 -0500 From: Haiyang Zhang To: Ben Hutchings CC: "davem@davemloft.net" , "netdev@vger.kernel.org" , KY Srinivasan , "olaf@aepfle.de" , "jasowang@redhat.com" , "linux-kernel@vger.kernel.org" , "driverdev-devel@linuxdriverproject.org" Subject: RE: [PATCH net-next] hyperv: Add support for Virtual Receive Side Scaling (vRSS) Thread-Topic: [PATCH net-next] hyperv: Add support for Virtual Receive Side Scaling (vRSS) Thread-Index: AQHO/DjpLyfIXxkiYUqDQo2oHD6XuZpcUhsA//+GhuA= Date: Thu, 19 Dec 2013 18:36:27 +0000 Message-ID: References: <1387405262-18334-1-git-send-email-haiyangz@microsoft.com> <1387475178.1876.29.camel@bwh-desktop.uk.level5networks.com> In-Reply-To: <1387475178.1876.29.camel@bwh-desktop.uk.level5networks.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [157.59.235.233] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 X-EOPAttributedMessage: 0 X-Forefront-Antispam-Report: CIP:131.107.159.100;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(10009001)(13464003)(377454003)(164054003)(377424004)(51704005)(189002)(199002)(24454002)(83072002)(47776003)(66066001)(63696002)(76482001)(74706001)(47736001)(2656002)(49866001)(54316002)(47446002)(20776003)(65816001)(80022001)(46102001)(47976001)(81686001)(59766001)(81342001)(77982001)(85306002)(80976001)(87266001)(85852003)(50986001)(56776001)(74662001)(76786001)(76796001)(81542001)(74876001)(50466002)(53806001)(4396001)(69226001)(79102001)(19580395003)(83322001)(19580405001)(54356001)(6806004)(74366001)(87936001)(90146001)(44976005)(81816001)(31966008)(51856001)(74502001)(33646001)(23676002)(56816005)(24736002);DIR:OUT;SFP:1101;SCL:1;SRVR:BY2SR01MB595;H:hybrid.exchange.microsoft.com;CLIP:131.107.159.100;FPR:;RD:InfoDomainNonexistent;MX:1;A:1;LANG:en; X-Forefront-PRVS: 006546F32A X-OriginatorOrg: microsoft.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id rBJIbCBJ006822 > -----Original Message----- > From: Ben Hutchings [mailto:bhutchings@solarflare.com] > Sent: Thursday, December 19, 2013 12:46 PM > To: Haiyang Zhang > Cc: davem@davemloft.net; netdev@vger.kernel.org; KY Srinivasan; > olaf@aepfle.de; jasowang@redhat.com; linux-kernel@vger.kernel.org; > driverdev-devel@linuxdriverproject.org > Subject: Re: [PATCH net-next] hyperv: Add support for Virtual Receive Side > Scaling (vRSS) > > On Wed, 2013-12-18 at 14:21 -0800, Haiyang Zhang wrote: > > This feature allows multiple channels to be used by each virtual NIC. > > It is available on Hyper-V host 2012 R2. > > } else if (ret == -EAGAIN) { > > - netif_stop_queue(ndev); > > + netif_tx_stop_all_queues(ndev); > > if (atomic_read(&net_device->num_outstanding_sends) < 1) { > > - netif_wake_queue(ndev); > > + netif_tx_wake_all_queues(ndev); > > ret = -ENOSPC; > > } > > } else { > > This doesn't makes any sense to me. How can you safely share the same > channels between all TX queues? > > I think you need to associate TX queues and channels 1-1. If you are required to > map packets to TX queues using the Toeplitz hash, you should implement > ndo_select_queue and do the mapping there. Then in > netvsc_send() you would use the queue number from the skb to find which > channel to use and which queue may need to be stopped/woken. > > [...] > > --- a/drivers/net/hyperv/netvsc_drv.c > > +++ b/drivers/net/hyperv/netvsc_drv.c > [...] > > +/* Toeplitz hash function > > + * data: network byte order > > + * return: host byte order > > + */ > > This looks incredibly slow. I've seen software implementations that are likely to > be more efficient, e.g. > > > [...] > > int netvsc_probe(struct hv_device *dev, > > return ret; > > } > > memcpy(net->dev_addr, device_info.mac_adr, ETH_ALEN); > > + nvdev = hv_get_drvdata(dev); > > + rtnl_lock(); > > + netif_set_real_num_tx_queues(net, nvdev->num_chn); > > + netif_set_real_num_rx_queues(net, nvdev->num_chn); > [...] > > These functions can fail if called after registering the net device, so you should > either call them with the final values earlier or handle failure here. > > Also, I notice that dev_addr is only set after registering; that should be fixed. > Thank you for the suggestions! I will re-write the send queue selection, enhance the hash calculation, also fix the initialization sequence. Thanks, - Haiyang {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I