From: "Wu, Jingjing" <jingjing.wu@intel.com>
To: "Sexton, Rory" <rory.sexton@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"Marjanovic, Nemanja" <nemanja.marjanovic@intel.com>
Subject: Re: [dpdk-dev] [PATCH v2] net/i40e: set no drop for traffic class
Date: Tue, 17 Jan 2017 15:09:15 +0000 [thread overview]
Message-ID: <9BB6961774997848B5B42BEC655768F810CCA338@SHSMSX103.ccr.corp.intel.com> (raw)
In-Reply-To: <1484581948-10736-1-git-send-email-rory.sexton@intel.com>
> -----Original Message-----
> From: Sexton, Rory
> Sent: Monday, January 16, 2017 11:52 PM
> To: Wu, Jingjing <jingjing.wu@intel.com>
> Cc: dev@dpdk.org; Sexton, Rory <rory.sexton@intel.com>; Marjanovic,
> Nemanja <nemanja.marjanovic@intel.com>
> Subject: [PATCH v2] net/i40e: set no drop for traffic class
>
> From: Rory Sexton <rory.sexton@intel.com>
>
> The default traffic class in i40e is set to drop versus on ixgbe it isset to no
> drop. This means when packets build up in the RX SRAM on the NIC, they are
> dropped, and they do this when the SW descriptor rings fill up.
>
> This patch changes this behaviour and our testing shows there are no drops
> as a result.
>
> Signed-off-by: Rory Sexton <rory.sexton@intel.com>
> Signed-off-by: Nemanja Marjanovic <nemanja.marjanovic@intel.com>
> ---
> v2:
> * Changed to use existing api to set priority register directly.
>
> drivers/net/i40e/i40e_ethdev.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
> index 67778ba..97339b5 100644
> --- a/drivers/net/i40e/i40e_ethdev.c
> +++ b/drivers/net/i40e/i40e_ethdev.c
> @@ -2985,8 +2985,11 @@ static int
> i40e_priority_flow_ctrl_set(__rte_unused struct rte_eth_dev *dev,
> __rte_unused struct rte_eth_pfc_conf *pfc_conf)
> {
> + struct i40e_hw *hw = I40E_DEV_PRIVATE_TO_HW(dev->data-
> >dev_private);
> +
> PMD_INIT_FUNC_TRACE();
>
> + I40E_WRITE_REG(hw, I40E_PRTDCB_TC2PFC, 0xff);
PRTDCB_TC2PFC is the Bitmap who controls the use of Priority Flow Control (PFC) per each
TC. Bit n set to 1b indicates TC n uses PFC in Rx and Tx. The TC is referred as a no-drop TC.
And if look the rte_eth_pfc_conf, there is a field called priority, which would map to a TC.
Currently, the TC and priority is 1:1 map when dcb is enabled.
So how about change it like:
Check dcb info, and map the priority to tc, then
val = 0x1 << tc;
I40E_WRITE_REG(hw, I40E_PRTDCB_TC2PFC, val);
Thanks
Jingjing
> return -ENOSYS;
> }
>
> --
> 2.4.3
next prev parent reply other threads:[~2017-01-17 15:09 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-04 13:54 [dpdk-dev] [PATCH v1] " Rory Sexton
2016-12-05 8:44 ` Wu, Jingjing
2016-12-09 14:02 ` Sexton, Rory
2016-12-26 8:45 ` Wu, Jingjing
2017-01-16 15:52 ` [dpdk-dev] [PATCH v2] " rory.sexton
2017-01-17 15:09 ` Wu, Jingjing [this message]
2017-01-19 10:38 ` Sexton, Rory
2017-02-07 15:25 ` Wu, Jingjing
2017-02-09 15:34 ` Ferruh Yigit
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