From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f45.google.com (mail-wm0-f45.google.com [74.125.82.45]) by dpdk.org (Postfix) with ESMTP id 87919201 for ; Thu, 22 Mar 2018 11:46:21 +0100 (CET) Received: by mail-wm0-f45.google.com with SMTP id x82so15133667wmg.1 for ; Thu, 22 Mar 2018 03:46:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=6wind-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=Zlu2u885inEyYEbeqWlZTzNiv1dyoKmTKkC9Yc6mngk=; b=RT8ZPYlKfSMY6nSe4iIO7I0LqVx0oUnhQH4b4qF0xPNQcICw9Dx63BFpWVWMpCoQxk fAfIFrFiJZNy9h5bpUixewhje8VemgFQq2x/E4EEchlD2vrFtxq7YCTGHASkVC8esnpT C1OdC1jSReEv7/0mw6QoS/44jOrYHWns74ZG8B/EjBiflrbwG6AqAm1HWrcxCny0Mk8o laUwqAOoyDo7O6DTm853fqgluiHSnWReRG/06PUCHjzqGXilcjMQYFwRcKPEoXCkY+DC eXhfMPvWqCtQQQ8woCW+/c5jNuOgnsfFTK2Jquos5ZxOJoy4OWqyd9Ir4sVqeatAHZ4s Luhw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=Zlu2u885inEyYEbeqWlZTzNiv1dyoKmTKkC9Yc6mngk=; b=JGDQ5HbALZzDKrKwxO/sW7RWHagB2C8KnrHOLfCUNgmpmnwNcm1jvOGtTsbtc8BsgQ QfjNPs2gHxUoxZdsiuAsu9z04ZmBNXgSdf4sv5/RBLTaCyvJXGK+0zjoqODmpPWRtzbp tApB9yRv4zjVrnjzeFuUmqpyZyt37G+tuFip2S5mNmN94h7mAkNsEXNGLOnDbXeugqRt 5TFCAVtledz3N1CGAp3SpdXuOPRgPOA/eraa4FG7ICdqdUxSvLqXQDv207eAwtA6s+jr JCoGeA8MxLzGU4GOk8uU7j2YUfjoAX42tllfsXNQ8B7vMpFo54bhyIF9rPA+pzF/CPWl 3AbA== X-Gm-Message-State: AElRT7HPXAkwPa7PMn15bWBmUd5sJ9RvYz2d0XrsRHGcuf50m2HDJNVb VCsRuUmEMNIceurF2uB8HS07 X-Google-Smtp-Source: AG47ELuhyU6qUg3Ydx3Oi80Jl8Ed+VYbQloyX90acSi6nZ+pWtyjsr0qT7rMysekngfk59+d5rzPbQ== X-Received: by 10.28.144.134 with SMTP id s128mr4803664wmd.4.1521715581146; Thu, 22 Mar 2018 03:46:21 -0700 (PDT) Received: from laranjeiro-vm.dev.6wind.com (host.78.145.23.62.rev.coltfrance.com. [62.23.145.78]) by smtp.gmail.com with ESMTPSA id k1sm7820683wrf.66.2018.03.22.03.46.20 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 22 Mar 2018 03:46:20 -0700 (PDT) Date: Thu, 22 Mar 2018 11:45:31 +0100 From: =?iso-8859-1?Q?N=E9lio?= Laranjeiro To: "Hanoch Haim (hhaim)" Cc: Yongseok Koh , "dev@dpdk.org" Message-ID: <20180322104531.ivfs3hdqezobcxjn@laranjeiro-vm.dev.6wind.com> References: <1b6a9384a5604f15948162766cde90a9@XCH-RTP-017.cisco.com> <20180321214749.GA53128@yongseok-MBP.local> <20180322085441.a3o2eyvols7jkzxo@laranjeiro-vm.dev.6wind.com> <92a7d23b9df748b6af83f7dda88672e4@XCH-RTP-017.cisco.com> <20180322092734.6iulb7yxfkbdsi3h@laranjeiro-vm.dev.6wind.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Subject: Re: [dpdk-dev] mlx5 reta size is dynamic 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, 22 Mar 2018 10:46:21 -0000 Hi Hanoch, On Thu, Mar 22, 2018 at 10:00:45AM +0000, Hanoch Haim (hhaim) wrote: > Hi Nelio, > > Let me provide more background. > The context is TRex running in Advance Stateful (ASTf) mode using multi-core. > In this case the flows are distributed using RSS. New flows (c->s) > need to have a tuple that will match the generated core. For this > calculation there is a need of to know the *RETA table size* > > > Code: > > /*1. verify that driver can support RSS */ > rte_eth_dev_info_get(m_repid,&dev_info); > save_reta_size = dev_info.reta_size > save_hash_key = dev_info.hash_key_size > printf("RETA_SIZE : %d \n",save_reta_size); > printf("HASH_SIZE : %d \n",save_hash_key); > > /*2. configure queues */ > ret = rte_eth_dev_configure(m_repid, > nb_rx_queue, > nb_tx_queue, > eth_conf); > .. > > /* 3. reading the RETA again */ > rte_eth_dev_info_get(m_repid,&dev_info); > save_reta_size = dev_info.reta_size << > save_hash_key = dev_info.hash_key_size > printf("RETA_SIZE1 : %d \n",save_reta_size); > > > /* 4. update the RETA table */ > rte_eth_dev_rss_reta_update(m_repid, &reta_conf[0], dev_info.reta_size) > > > 2. /*Output in case of Intel i40e*/ > > RETA_SIZE : 512 > HASH_SIZE : 52 > > RETA_SIZE1 : 512 > > 3. /*Output in case of Mlx5 */ > > RETA_SIZE : 512 > HASH_SIZE : 0 > > RETA_SIZE1 : 4 << not round of 64 , depends on the number of rx queues Your need is to have a fixed size returned by the rte_eth_dev_info_get(), the PMD can have an internal dynamic size, it won't modify your spreading. An information, you are getting the hash key size, according to the documentation of struct rte_eth_rss_conf, only the i40e can have a key len different from 40 bytes, others should just ignore the field [1]. Regards, [1] https://dpdk.org/browse/dpdk/tree/lib/librte_ether/rte_ethdev.h#n380 > Hanoh > > -----Original Message----- > From: Nélio Laranjeiro [mailto:nelio.laranjeiro@6wind.com] > Sent: Thursday, March 22, 2018 11:28 AM > To: Hanoch Haim (hhaim) > Cc: Yongseok Koh; dev@dpdk.org > Subject: Re: [dpdk-dev] mlx5 reta size is dynamic > > Hi Hanoch, > > On Thu, Mar 22, 2018 at 09:02:19AM +0000, Hanoch Haim (hhaim) wrote: > > Hi Nelio, > > I think you didn't understand me. I suggest to keep the RETA table > > size constant (maximum 512 in your case) and don't change its base on > > the number of configured Rx-queue. > > It is even simpler, we can return the maximum size or a multiple of RTE_RETA_GROUP_SIZE according to the number of Rx queues being used, in the devop->dev_infos_get() as it is what the > rte_eth_dev_rss_reta_update() implementation will expect. > > > This will make the DPDK API consistent. As a user I need to do tricks > > (allocate an odd/prime number of rx-queues) to get the RETA size > > constant at 512 > > I understand this issue, what I don't fully understand your needs. > > > I'm not talking about changing the values in the RETA table which can > > be done while there is traffic. > > On MLX5 changing the entries of the RETA table don't affect the current traffic, it needs a port restart to affect it and only for "default" > flows, any flow created through the public flow API are not impacted by the RETA table. > > > From my understanding, you wish to have a size returned by > devop->dev_infos_get() usable directly by rte_eth_dev_rss_reta_update(). > This is why you are asking for a fix size? So, if internally the PMD starts with a smaller RETA table does not really matter, until the RETA API works without any trick from the application side. Is this correct? > > Thanks, > > > Thanks, > > Hanoh > > > > > > -----Original Message----- > > From: Nélio Laranjeiro [mailto:nelio.laranjeiro@6wind.com] > > Sent: Thursday, March 22, 2018 10:55 AM > > To: Hanoch Haim (hhaim) > > Cc: Yongseok Koh; dev@dpdk.org > > Subject: Re: [dpdk-dev] mlx5 reta size is dynamic > > > > On Thu, Mar 22, 2018 at 06:52:53AM +0000, Hanoch Haim (hhaim) wrote: > > > Hi Yongseok, > > > > > > > > > RSS has a DPDK API,application can ask for the reta table size and > > > configure it. In your case you are assuming specific use case and > > > change the size dynamically which solve 90% of the use-cases but > > > break the 10% use-case. > > > Instead, you could provide the application a consistent API and with > > > that 100% of the applications can work with no issue. This is what > > > happen with Intel (ixgbe/i40e) Another minor issue the rss_key_size > > > return as zero but internally it is 40 bytes > > > > Hi Hanoch, > > > > Legacy DPDK API has always considered there is only a single indirection table aka. RETA whereas this is not true [1][2] on this device. > > > > On MLX5 there is an indirection table per Hash Rx queue according to the list of queues making part of it. > > The Hash Rx queue is configured to make the hash with configured > > information: > > - Algorithm, > > - key > > - hash field (Verbs hash field) > > - Indirection table > > An Hash Rx queue cannot handle multiple RSS configuration, we have an Hash Rx queue per protocol and thus a full configuration per protocol. > > > > In such situation, changing the RETA means stopping the traffic, destroying every single flow, hash Rx queue, indirection table to remake everything with the new configuration. > > Until then, we always recommended to any application to restart the port on this device after a RETA update to apply this new configuration. > > > > Since the flow API is the new way to configure flows, application should move to this new one instead of using old API for such behavior. > > We should also remove such devop from the PMD to avoid any confusion. > > > > Regards, > > > > > Thanks, > > > Hanoh > > > > > > -----Original Message----- > > > From: Yongseok Koh [mailto:yskoh@mellanox.com] > > > Sent: Wednesday, March 21, 2018 11:48 PM > > > To: Hanoch Haim (hhaim) > > > Cc: dev@dpdk.org > > > Subject: Re: [dpdk-dev] mlx5 reta size is dynamic > > > > > > On Wed, Mar 21, 2018 at 06:56:33PM +0000, Hanoch Haim (hhaim) wrote: > > > > Hi mlx5 driver expert, > > > > > > > > DPDK: 17.11 > > > > Any reason mlx5 driver change the rate table size dynamically > > > > based on the rx- queues# ? > > > > > > The device only supports 2^n-sized indirection table. For example, if the number of Rx queues is 6, device can't have 1-1 mapping but the size of ind tbl could be 8, 16, 32 and so on. If we configure it as 8 for example, 2 out of 6 queues will have 1/4 of traffic while the rest 4 queues receives 1/8. We thought it was too much disparity and preferred setting the max size in order to mitigate the imbalance. > > > > > > > There is a hidden assumption that the user wants to distribute the > > > > packets evenly which is not always correct. > > > > > > But it is mostly correct because RSS is used for uniform distribution. The decision wasn't made based on our speculation but by many request from multiple customers. > > > > > > > /* If the requested number of RX queues is not a power of two, use the > > > > * maximum indirection table size for better balancing. > > > > * The result is always rounded to the next power of two. */ > > > > reta_idx_n = (1 << log2above((rxqs_n & (rxqs_n - 1)) ? > > > > priv->ind_table_max_size : > > > > rxqs_n)); > > > > > > Thanks, > > > Yongseok > > > > [1] https://dpdk.org/ml/archives/dev/2015-October/024668.html > > [2] https://dpdk.org/ml/archives/dev/2015-October/024669.html > > > > -- > > Nélio Laranjeiro > > 6WIND > > -- > Nélio Laranjeiro > 6WIND -- Nélio Laranjeiro 6WIND