diff mbox

[dpdk-dev,v2] net/i40e: set no drop for traffic class

Message ID 1484581948-10736-1-git-send-email-rory.sexton@intel.com (mailing list archive)
State Rejected, archived
Delegated to: Ferruh Yigit
Headers

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel compilation success Compilation OK

Commit Message

Sexton, Rory Jan. 16, 2017, 3:52 p.m. UTC 
  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(+)

Comments

Jingjing Wu Jan. 17, 2017, 3:09 p.m. UTC | #1 
> -----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
Sexton, Rory Jan. 19, 2017, 10:38 a.m. UTC | #2 
Perhaps the best solution is as suggested to set
rte_eth_conf.dcb_capability_en = ETH_DCB_PFC_SUPPORT
rte_eth_conf.rxmode.mq_mode = ETH_MQ_RX_DCB_FLAG
and set rte_eth_dcb_rx_conf.nb_tcs to the number of tc's to apply
Using this port configuration will give the same behavior of the patch and it removes the need for an API change.

Rory

-----Original Message-----
From: Wu, Jingjing 
Sent: Tuesday, January 17, 2017 3:09 PM
To: Sexton, Rory <rory.sexton@intel.com>
Cc: dev@dpdk.org; Marjanovic, Nemanja <nemanja.marjanovic@intel.com>
Subject: RE: [PATCH v2] net/i40e: set no drop for traffic class



> -----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

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Jingjing Wu Feb. 7, 2017, 3:25 p.m. UTC | #3 
> -----Original Message-----
> From: Sexton, Rory
> Sent: Thursday, January 19, 2017 6:38 PM
> To: Wu, Jingjing <jingjing.wu@intel.com>
> Cc: dev@dpdk.org; Marjanovic, Nemanja <nemanja.marjanovic@intel.com>
> Subject: RE: [PATCH v2] net/i40e: set no drop for traffic class
> 
> Perhaps the best solution is as suggested to set rte_eth_conf.dcb_capability_en
> = ETH_DCB_PFC_SUPPORT rte_eth_conf.rxmode.mq_mode =
> ETH_MQ_RX_DCB_FLAG and set rte_eth_dcb_rx_conf.nb_tcs to the number of
> tc's to apply Using this port configuration will give the same behavior of the
> patch and it removes the need for an API change.
> 
> Rory
> 
Yes, That's what I thought when the v1 patch. So do we still need this patch now?

> -----Original Message-----
> From: Wu, Jingjing
> Sent: Tuesday, January 17, 2017 3:09 PM
> To: Sexton, Rory <rory.sexton@intel.com>
> Cc: dev@dpdk.org; Marjanovic, Nemanja <nemanja.marjanovic@intel.com>
> Subject: RE: [PATCH v2] net/i40e: set no drop for traffic class
> 
> 
> 
> > -----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
Ferruh Yigit Feb. 9, 2017, 3:34 p.m. UTC | #4 
On 2/7/2017 3:25 PM, Wu, Jingjing wrote:
> 
> 
>> -----Original Message-----
>> From: Sexton, Rory
>> Sent: Thursday, January 19, 2017 6:38 PM
>> To: Wu, Jingjing <jingjing.wu@intel.com>
>> Cc: dev@dpdk.org; Marjanovic, Nemanja <nemanja.marjanovic@intel.com>
>> Subject: RE: [PATCH v2] net/i40e: set no drop for traffic class
>>
>> Perhaps the best solution is as suggested to set rte_eth_conf.dcb_capability_en
>> = ETH_DCB_PFC_SUPPORT rte_eth_conf.rxmode.mq_mode =
>> ETH_MQ_RX_DCB_FLAG and set rte_eth_dcb_rx_conf.nb_tcs to the number of
>> tc's to apply Using this port configuration will give the same behavior of the
>> patch and it removes the need for an API change.
>>
>> Rory
>>
> Yes, That's what I thought when the v1 patch. So do we still need this patch now?

I guess answer is No.
The patch is marked as "Rejected" in patchwork, please shout if that is
not the case.

Thanks,
ferruh
diff mbox

Patch

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);
 	return -ENOSYS;
 }