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From: Thomas Monjalon <thomas@monjalon.net>
To: Carsten Andrich <carsten.andrich@tu-ilmenau.de>
Cc: users@dpdk.org, viacheslavo@nvidia.com
Subject: Re: [dpdk-users] MLX5: Using packet send scheduling / packet pacing
Date: Fri, 29 Jan 2021 17:50:20 +0100
Message-ID: <1768623.GMc5ikO6cA@thomas> (raw)
In-Reply-To: <43ddc3a8-a48f-0930-a2da-9e2fcdde1b98@tu-ilmenau.de>

+Cc Slava

29/01/2021 17:30, Carsten Andrich:
> Hello everyone,
> 
> I'm trying to use packet send scheduling [1] with DPDK 20.11 and the 
> MLX5 PMD (NIC: ConnectX-5 MCX516A-CDAT). This patch contains some 
> additional information on this feature also know as packet pacing [2].
> 
> According to MLX5's docs, packet pacing requires the "tx_pp" parameter 
> [3, CTRL+F: "tx_pp"]. However, when firing up testpmd with that 
> parameter, it fails as follows:
> 
> > # dpdk-testpmd -a 81:00.0,tx_pp=500 -- -i
> > ...
> > EAL: Probe PCI driver: mlx5_pci (15b3:1019) device: 0000:81:00.0 (socket 0)
> > mlx5_pci: WQE rate mode is required for packet pacing
> > mlx5_pci: probe of PCI device 0000:81:00.0 aborted after encountering an error: No such device
> > common_mlx5: Failed to load driver = mlx5_pci.
> >
> > EAL: Requested device 0000:81:00.0 cannot be used
> The error message originates here [4] and is caused by what to me 
> appears to be a value read from the NIC [5]. Unfortunately, that leaves 
> me clueless on how to activate the required "WQE rate mode".  According 
> to the output of ibv_devinfo, my NIC does support packet pacing:
> 
> > # ibv_devinfo -v 81:00.0
> > ...
> > 	packet_pacing_caps:
> > 		qp_rate_limit_min:	1kbps
> > 		qp_rate_limit_max:	100000000kbps
> > 		supported_qp:
> > 					SUPPORT_RAW_PACKET
> I'd be grateful for any information on how to get packet pacing up and 
> running. Am I just missing another required option (which is not given 
> in the docs) or does my NIC lack packet pacing support?
> 
> Thank you very much in advance.
> 
> Best regards,
> Carsten
> 
> [1] 
> https://doc.dpdk.org/api/rte__ethdev_8h.html#a990d8351447a710628cbb24a28d3252d
> [2] https://patches.dpdk.org/patch/73742/
> [3] https://doc.dpdk.org/guides/nics/mlx5.html#run-time-configuration
> [4] 
> http://code.dpdk.org/dpdk/v20.11/source/drivers/net/mlx5/linux/mlx5_os.c#L1278
> [5] 
> http://code.dpdk.org/dpdk/v20.11/source/drivers/common/mlx5/mlx5_devx_cmds.c#L748
> 
> 






  reply	other threads:[~2021-01-29 16:50 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-29 16:30 Carsten Andrich
2021-01-29 16:50 ` Thomas Monjalon [this message]
2021-01-29 18:04   ` Slava Ovsiienko
2021-01-30 10:54     ` Carsten Andrich
2021-01-30 13:13       ` Thomas Monjalon

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