[PATCH v1] net/i40e: remove redundant number of packets check

[PATCH v1] net/i40e: remove redundant number of packets check

[Feifei Wang]

For i40e_xmit_pkts_vec_xx function, it checks nb_pkts to ensure nb_pkts
does not cross rs_thresh.

However, in i40e_xmit_fixed_burst_vec_xx function, this check will be
performed again. To improve code, delete this redundant check.

Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
 drivers/net/i40e/i40e_rxtx.c             | 1 +
 drivers/net/i40e/i40e_rxtx_vec_altivec.c | 3 ---
 drivers/net/i40e/i40e_rxtx_vec_avx2.c    | 4 +---
 drivers/net/i40e/i40e_rxtx_vec_avx512.c  | 4 +---
 drivers/net/i40e/i40e_rxtx_vec_neon.c    | 3 ---
 drivers/net/i40e/i40e_rxtx_vec_sse.c     | 3 ---
 6 files changed, 3 insertions(+), 15 deletions(-)

diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
index 25a28ecea2..788ffb51c2 100644
--- a/drivers/net/i40e/i40e_rxtx.c
+++ b/drivers/net/i40e/i40e_rxtx.c
@@ -1523,6 +1523,7 @@ i40e_xmit_pkts_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
 	while (nb_pkts) {
 		uint16_t ret, num;
 
+		/* cross rs_thresh boundary is not allowed */
 		num = (uint16_t)RTE_MIN(nb_pkts, txq->tx_rs_thresh);
 		ret = i40e_xmit_fixed_burst_vec(tx_queue, &tx_pkts[nb_tx],
 						num);
diff --git a/drivers/net/i40e/i40e_rxtx_vec_altivec.c b/drivers/net/i40e/i40e_rxtx_vec_altivec.c
index f78ba994f7..825834c5cd 100644
--- a/drivers/net/i40e/i40e_rxtx_vec_altivec.c
+++ b/drivers/net/i40e/i40e_rxtx_vec_altivec.c
@@ -560,9 +560,6 @@ i40e_xmit_fixed_burst_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
 	uint64_t rs = I40E_TX_DESC_CMD_RS | I40E_TD_CMD;
 	int i;
 
-	/* cross rx_thresh boundary is not allowed */
-	nb_pkts = RTE_MIN(nb_pkts, txq->tx_rs_thresh);
-
 	if (txq->nb_tx_free < txq->tx_free_thresh)
 		i40e_tx_free_bufs(txq);
 
diff --git a/drivers/net/i40e/i40e_rxtx_vec_avx2.c b/drivers/net/i40e/i40e_rxtx_vec_avx2.c
index c73b2a321b..761edb9d20 100644
--- a/drivers/net/i40e/i40e_rxtx_vec_avx2.c
+++ b/drivers/net/i40e/i40e_rxtx_vec_avx2.c
@@ -766,9 +766,6 @@ i40e_xmit_fixed_burst_vec_avx2(void *tx_queue, struct rte_mbuf **tx_pkts,
 	uint64_t flags = I40E_TD_CMD;
 	uint64_t rs = I40E_TX_DESC_CMD_RS | I40E_TD_CMD;
 
-	/* cross rx_thresh boundary is not allowed */
-	nb_pkts = RTE_MIN(nb_pkts, txq->tx_rs_thresh);
-
 	if (txq->nb_tx_free < txq->tx_free_thresh)
 		i40e_tx_free_bufs(txq);
 
@@ -832,6 +829,7 @@ i40e_xmit_pkts_vec_avx2(void *tx_queue, struct rte_mbuf **tx_pkts,
 	while (nb_pkts) {
 		uint16_t ret, num;
 
+		/* cross rs_thresh boundary is not allowed */
 		num = (uint16_t)RTE_MIN(nb_pkts, txq->tx_rs_thresh);
 		ret = i40e_xmit_fixed_burst_vec_avx2(tx_queue, &tx_pkts[nb_tx],
 						num);
diff --git a/drivers/net/i40e/i40e_rxtx_vec_avx512.c b/drivers/net/i40e/i40e_rxtx_vec_avx512.c
index 2e8a3f0df6..60c97d5331 100644
--- a/drivers/net/i40e/i40e_rxtx_vec_avx512.c
+++ b/drivers/net/i40e/i40e_rxtx_vec_avx512.c
@@ -1060,9 +1060,6 @@ i40e_xmit_fixed_burst_vec_avx512(void *tx_queue, struct rte_mbuf **tx_pkts,
 	uint64_t flags = I40E_TD_CMD;
 	uint64_t rs = I40E_TX_DESC_CMD_RS | I40E_TD_CMD;
 
-	/* cross rx_thresh boundary is not allowed */
-	nb_pkts = RTE_MIN(nb_pkts, txq->tx_rs_thresh);
-
 	if (txq->nb_tx_free < txq->tx_free_thresh)
 		i40e_tx_free_bufs_avx512(txq);
 
@@ -1127,6 +1124,7 @@ i40e_xmit_pkts_vec_avx512(void *tx_queue, struct rte_mbuf **tx_pkts,
 	while (nb_pkts) {
 		uint16_t ret, num;
 
+		/* cross rs_thresh boundary is not allowed */
 		num = (uint16_t)RTE_MIN(nb_pkts, txq->tx_rs_thresh);
 		ret = i40e_xmit_fixed_burst_vec_avx512
 				(tx_queue, &tx_pkts[nb_tx], num);
diff --git a/drivers/net/i40e/i40e_rxtx_vec_neon.c b/drivers/net/i40e/i40e_rxtx_vec_neon.c
index 6433f9d051..be2d8d08ca 100644
--- a/drivers/net/i40e/i40e_rxtx_vec_neon.c
+++ b/drivers/net/i40e/i40e_rxtx_vec_neon.c
@@ -682,9 +682,6 @@ i40e_xmit_fixed_burst_vec(void *__rte_restrict tx_queue,
 	uint64_t rs = I40E_TX_DESC_CMD_RS | I40E_TD_CMD;
 	int i;
 
-	/* cross rx_thresh boundary is not allowed */
-	nb_pkts = RTE_MIN(nb_pkts, txq->tx_rs_thresh);
-
 	if (txq->nb_tx_free < txq->tx_free_thresh)
 		i40e_tx_free_bufs(txq);
 
diff --git a/drivers/net/i40e/i40e_rxtx_vec_sse.c b/drivers/net/i40e/i40e_rxtx_vec_sse.c
index 3782e8052f..bdc979a839 100644
--- a/drivers/net/i40e/i40e_rxtx_vec_sse.c
+++ b/drivers/net/i40e/i40e_rxtx_vec_sse.c
@@ -709,9 +709,6 @@ i40e_xmit_fixed_burst_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
 	uint64_t rs = I40E_TX_DESC_CMD_RS | I40E_TD_CMD;
 	int i;
 
-	/* cross rx_thresh boundary is not allowed */
-	nb_pkts = RTE_MIN(nb_pkts, txq->tx_rs_thresh);
-
 	if (txq->nb_tx_free < txq->tx_free_thresh)
 		i40e_tx_free_bufs(txq);
 
-- 
2.25.1

RE: [PATCH v1] net/i40e: remove redundant number of packets check

[Zhang, Qi Z]

> -----Original Message-----
> From: Feifei Wang <feifei.wang2@arm.com>
> Sent: Thursday, March 3, 2022 9:54 AM
> To: Xing, Beilei <beilei.xing@intel.com>; David Christensen
> <drc@linux.vnet.ibm.com>; Richardson, Bruce <bruce.richardson@intel.com>;
> Ananyev, Konstantin <konstantin.ananyev@intel.com>; Ruifeng Wang
> <ruifeng.wang@arm.com>
> Cc: dev@dpdk.org; nd@arm.com; Feifei Wang <feifei.wang2@arm.com>;
> Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> Subject: [PATCH v1] net/i40e: remove redundant number of packets check
> 
> For i40e_xmit_pkts_vec_xx function, it checks nb_pkts to ensure nb_pkts does
> not cross rs_thresh.
> 
> However, in i40e_xmit_fixed_burst_vec_xx function, this check will be
> performed again. To improve code, delete this redundant check.
> 
> Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>

Applied to dpdk-next-net-intel.

Thanks
Qi

Re: [PATCH v1] net/i40e: remove redundant number of packets check

[Ferruh Yigit]

On 3/3/2022 2:28 AM, Zhang, Qi Z wrote:
> 
> 
>> -----Original Message-----
>> From: Feifei Wang <feifei.wang2@arm.com>
>> Sent: Thursday, March 3, 2022 9:54 AM
>> To: Xing, Beilei <beilei.xing@intel.com>; David Christensen
>> <drc@linux.vnet.ibm.com>; Richardson, Bruce <bruce.richardson@intel.com>;
>> Ananyev, Konstantin <konstantin.ananyev@intel.com>; Ruifeng Wang
>> <ruifeng.wang@arm.com>
>> Cc: dev@dpdk.org; nd@arm.com; Feifei Wang <feifei.wang2@arm.com>;
>> Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
>> Subject: [PATCH v1] net/i40e: remove redundant number of packets check
>>
>> For i40e_xmit_pkts_vec_xx function, it checks nb_pkts to ensure nb_pkts does
>> not cross rs_thresh.
>>
>> However, in i40e_xmit_fixed_burst_vec_xx function, this check will be
>> performed again. To improve code, delete this redundant check.
>>
>> Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
>> Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
>> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> 
> Applied to dpdk-next-net-intel.
> 

Hi Qi,

This patch is not acked by the i40e maintainers.

And this is changing the datapath for the -rc3, two weeks before
the release. Is it tested enough?

What is the gain with this patch, I don't see any numbers
in the commit log.
If the gain is small, can we postpone this patch to next
release instead of getting it for -rc3?

RE: [PATCH v1] net/i40e: remove redundant number of packets check

[Zhang, Qi Z]

> -----Original Message-----
> From: Yigit, Ferruh <ferruh.yigit@intel.com>
> Sent: Friday, March 4, 2022 12:44 AM
> To: Zhang, Qi Z <qi.z.zhang@intel.com>; Feifei Wang <feifei.wang2@arm.com>;
> Xing, Beilei <beilei.xing@intel.com>; David Christensen
> <drc@linux.vnet.ibm.com>; Richardson, Bruce <bruce.richardson@intel.com>;
> Ananyev, Konstantin <konstantin.ananyev@intel.com>; Ruifeng Wang
> <ruifeng.wang@arm.com>
> Cc: dev@dpdk.org; nd@arm.com; Honnappa Nagarahalli
> <honnappa.nagarahalli@arm.com>; Thomas Monjalon
> <thomas@monjalon.net>; David Marchand <david.marchand@redhat.com>
> Subject: Re: [PATCH v1] net/i40e: remove redundant number of packets check
> 
> On 3/3/2022 2:28 AM, Zhang, Qi Z wrote:
> >
> >
> >> -----Original Message-----
> >> From: Feifei Wang <feifei.wang2@arm.com>
> >> Sent: Thursday, March 3, 2022 9:54 AM
> >> To: Xing, Beilei <beilei.xing@intel.com>; David Christensen
> >> <drc@linux.vnet.ibm.com>; Richardson, Bruce
> >> <bruce.richardson@intel.com>; Ananyev, Konstantin
> >> <konstantin.ananyev@intel.com>; Ruifeng Wang <ruifeng.wang@arm.com>
> >> Cc: dev@dpdk.org; nd@arm.com; Feifei Wang <feifei.wang2@arm.com>;
> >> Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> >> Subject: [PATCH v1] net/i40e: remove redundant number of packets
> >> check
> >>
> >> For i40e_xmit_pkts_vec_xx function, it checks nb_pkts to ensure
> >> nb_pkts does not cross rs_thresh.
> >>
> >> However, in i40e_xmit_fixed_burst_vec_xx function, this check will be
> >> performed again. To improve code, delete this redundant check.
> >>
> >> Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> >> Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
> >> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> >
> > Applied to dpdk-next-net-intel.
> >
> 
> Hi Qi,
> 
> This patch is not acked by the i40e maintainers.
> 
> And this is changing the datapath for the -rc3, two weeks before the release. Is
> it tested enough?
> 
> What is the gain with this patch, I don't see any numbers in the commit log.
> If the gain is small, can we postpone this patch to next release instead of getting
> it for -rc3?

The patch applied the same thing as below which I have reviewed.
https://patchwork.dpdk.org/project/dpdk/patch/20220222224818.8612-1-kathleen.capella@arm.com/

I didn't see the risk of having it, and I will add a "reviewed-by" to avoid confusion, but if you think it's risky, we can still defer it to next-net.

Thanks
Qi

回复: [PATCH v1] net/i40e: remove redundant number of packets check

[Feifei Wang]

> -----邮件原件-----
> 发件人: Zhang, Qi Z <qi.z.zhang@intel.com>
> 发送时间: Friday, March 4, 2022 9:24 AM
> 收件人: Yigit, Ferruh <ferruh.yigit@intel.com>; Feifei Wang
> <Feifei.Wang2@arm.com>; Xing, Beilei <beilei.xing@intel.com>; David
> Christensen <drc@linux.vnet.ibm.com>; Richardson, Bruce
> <bruce.richardson@intel.com>; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; Ruifeng Wang <Ruifeng.Wang@arm.com>
> 抄送: dev@dpdk.org; nd <nd@arm.com>; Honnappa Nagarahalli
> <Honnappa.Nagarahalli@arm.com>; thomas@monjalon.net; David Marchand
> <david.marchand@redhat.com>
> 主题: RE: [PATCH v1] net/i40e: remove redundant number of packets check
> 
> 
> 
> > -----Original Message-----
> > From: Yigit, Ferruh <ferruh.yigit@intel.com>
> > Sent: Friday, March 4, 2022 12:44 AM
> > To: Zhang, Qi Z <qi.z.zhang@intel.com>; Feifei Wang
> > <feifei.wang2@arm.com>; Xing, Beilei <beilei.xing@intel.com>; David
> > Christensen <drc@linux.vnet.ibm.com>; Richardson, Bruce
> > <bruce.richardson@intel.com>; Ananyev, Konstantin
> > <konstantin.ananyev@intel.com>; Ruifeng Wang <ruifeng.wang@arm.com>
> > Cc: dev@dpdk.org; nd@arm.com; Honnappa Nagarahalli
> > <honnappa.nagarahalli@arm.com>; Thomas Monjalon
> <thomas@monjalon.net>;
> > David Marchand <david.marchand@redhat.com>
> > Subject: Re: [PATCH v1] net/i40e: remove redundant number of packets
> > check
> >
> > On 3/3/2022 2:28 AM, Zhang, Qi Z wrote:
> > >
> > >
> > >> -----Original Message-----
> > >> From: Feifei Wang <feifei.wang2@arm.com>
> > >> Sent: Thursday, March 3, 2022 9:54 AM
> > >> To: Xing, Beilei <beilei.xing@intel.com>; David Christensen
> > >> <drc@linux.vnet.ibm.com>; Richardson, Bruce
> > >> <bruce.richardson@intel.com>; Ananyev, Konstantin
> > >> <konstantin.ananyev@intel.com>; Ruifeng Wang
> <ruifeng.wang@arm.com>
> > >> Cc: dev@dpdk.org; nd@arm.com; Feifei Wang <feifei.wang2@arm.com>;
> > >> Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> > >> Subject: [PATCH v1] net/i40e: remove redundant number of packets
> > >> check
> > >>
> > >> For i40e_xmit_pkts_vec_xx function, it checks nb_pkts to ensure
> > >> nb_pkts does not cross rs_thresh.
> > >>
> > >> However, in i40e_xmit_fixed_burst_vec_xx function, this check will
> > >> be performed again. To improve code, delete this redundant check.
> > >>
> > >> Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> > >> Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
> > >> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> > >
> > > Applied to dpdk-next-net-intel.
> > >
> >
> > Hi Qi,
> >
> > This patch is not acked by the i40e maintainers.
> >
> > And this is changing the datapath for the -rc3, two weeks before the
> > release. Is it tested enough?

Hi, Ferruh

Thanks for your remind. Test the performance in l3fwd with this patch:
In arm server, there is no performance change.
In x86 server, there is also no obvious performance change
according to performance test in public CI.

Best Regards
Feifei

> >
> > What is the gain with this patch, I don't see any numbers in the commit log.
> > If the gain is small, can we postpone this patch to next release
> > instead of getting it for -rc3?
> 
> The patch applied the same thing as below which I have reviewed.
> https://patchwork.dpdk.org/project/dpdk/patch/20220222224818.8612-1-
> kathleen.capella@arm.com/
> 
> I didn't see the risk of having it, and I will add a "reviewed-by" to avoid
> confusion, but if you think it's risky, we can still defer it to next-net.

Hi, Qi

Thanks for your review.

Best Regards
Feifei

> 
> Thanks
> Qi

Re: [PATCH v1] net/i40e: remove redundant number of packets check

[Ferruh Yigit]

On 3/4/2022 1:23 AM, Zhang, Qi Z wrote:
> 
> 
>> -----Original Message-----
>> From: Yigit, Ferruh <ferruh.yigit@intel.com>
>> Sent: Friday, March 4, 2022 12:44 AM
>> To: Zhang, Qi Z <qi.z.zhang@intel.com>; Feifei Wang <feifei.wang2@arm.com>;
>> Xing, Beilei <beilei.xing@intel.com>; David Christensen
>> <drc@linux.vnet.ibm.com>; Richardson, Bruce <bruce.richardson@intel.com>;
>> Ananyev, Konstantin <konstantin.ananyev@intel.com>; Ruifeng Wang
>> <ruifeng.wang@arm.com>
>> Cc: dev@dpdk.org; nd@arm.com; Honnappa Nagarahalli
>> <honnappa.nagarahalli@arm.com>; Thomas Monjalon
>> <thomas@monjalon.net>; David Marchand <david.marchand@redhat.com>
>> Subject: Re: [PATCH v1] net/i40e: remove redundant number of packets check
>>
>> On 3/3/2022 2:28 AM, Zhang, Qi Z wrote:
>>>
>>>
>>>> -----Original Message-----
>>>> From: Feifei Wang <feifei.wang2@arm.com>
>>>> Sent: Thursday, March 3, 2022 9:54 AM
>>>> To: Xing, Beilei <beilei.xing@intel.com>; David Christensen
>>>> <drc@linux.vnet.ibm.com>; Richardson, Bruce
>>>> <bruce.richardson@intel.com>; Ananyev, Konstantin
>>>> <konstantin.ananyev@intel.com>; Ruifeng Wang <ruifeng.wang@arm.com>
>>>> Cc: dev@dpdk.org; nd@arm.com; Feifei Wang <feifei.wang2@arm.com>;
>>>> Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
>>>> Subject: [PATCH v1] net/i40e: remove redundant number of packets
>>>> check
>>>>
>>>> For i40e_xmit_pkts_vec_xx function, it checks nb_pkts to ensure
>>>> nb_pkts does not cross rs_thresh.
>>>>
>>>> However, in i40e_xmit_fixed_burst_vec_xx function, this check will be
>>>> performed again. To improve code, delete this redundant check.
>>>>
>>>> Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
>>>> Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
>>>> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
>>>
>>> Applied to dpdk-next-net-intel.
>>>
>>
>> Hi Qi,
>>
>> This patch is not acked by the i40e maintainers.
>>
>> And this is changing the datapath for the -rc3, two weeks before the release. Is
>> it tested enough?
>>
>> What is the gain with this patch, I don't see any numbers in the commit log.
>> If the gain is small, can we postpone this patch to next release instead of getting
>> it for -rc3?
> 
> The patch applied the same thing as below which I have reviewed.
> https://patchwork.dpdk.org/project/dpdk/patch/20220222224818.8612-1-kathleen.capella@arm.com/
> 
> I didn't see the risk of having it, and I will add a "reviewed-by" to avoid confusion, but if you think it's risky, we can still defer it to next-net.
> 

Code change looks simple, but risk is more theoretical
to get a datapath code optimization close to the release,
and Feifei reported that there is no visible performance
gain.
So I think safer to postpone to next release if you don't
object.

RE: [PATCH v1] net/i40e: remove redundant number of packets check

[Zhang, Qi Z]

> -----Original Message-----
> From: Yigit, Ferruh <ferruh.yigit@intel.com>
> Sent: Friday, March 4, 2022 7:10 PM
> To: Zhang, Qi Z <qi.z.zhang@intel.com>; Feifei Wang
> <feifei.wang2@arm.com>; Xing, Beilei <beilei.xing@intel.com>; David
> Christensen <drc@linux.vnet.ibm.com>; Richardson, Bruce
> <bruce.richardson@intel.com>; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; Ruifeng Wang <ruifeng.wang@arm.com>
> Cc: dev@dpdk.org; nd@arm.com; Honnappa Nagarahalli
> <honnappa.nagarahalli@arm.com>; Thomas Monjalon
> <thomas@monjalon.net>; David Marchand <david.marchand@redhat.com>
> Subject: Re: [PATCH v1] net/i40e: remove redundant number of packets
> check
> 
> On 3/4/2022 1:23 AM, Zhang, Qi Z wrote:
> >
> >
> >> -----Original Message-----
> >> From: Yigit, Ferruh <ferruh.yigit@intel.com>
> >> Sent: Friday, March 4, 2022 12:44 AM
> >> To: Zhang, Qi Z <qi.z.zhang@intel.com>; Feifei Wang
> >> <feifei.wang2@arm.com>; Xing, Beilei <beilei.xing@intel.com>; David
> >> Christensen <drc@linux.vnet.ibm.com>; Richardson, Bruce
> >> <bruce.richardson@intel.com>; Ananyev, Konstantin
> >> <konstantin.ananyev@intel.com>; Ruifeng Wang
> <ruifeng.wang@arm.com>
> >> Cc: dev@dpdk.org; nd@arm.com; Honnappa Nagarahalli
> >> <honnappa.nagarahalli@arm.com>; Thomas Monjalon
> >> <thomas@monjalon.net>; David Marchand
> <david.marchand@redhat.com>
> >> Subject: Re: [PATCH v1] net/i40e: remove redundant number of packets
> >> check
> >>
> >> On 3/3/2022 2:28 AM, Zhang, Qi Z wrote:
> >>>
> >>>
> >>>> -----Original Message-----
> >>>> From: Feifei Wang <feifei.wang2@arm.com>
> >>>> Sent: Thursday, March 3, 2022 9:54 AM
> >>>> To: Xing, Beilei <beilei.xing@intel.com>; David Christensen
> >>>> <drc@linux.vnet.ibm.com>; Richardson, Bruce
> >>>> <bruce.richardson@intel.com>; Ananyev, Konstantin
> >>>> <konstantin.ananyev@intel.com>; Ruifeng Wang
> <ruifeng.wang@arm.com>
> >>>> Cc: dev@dpdk.org; nd@arm.com; Feifei Wang
> <feifei.wang2@arm.com>;
> >>>> Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> >>>> Subject: [PATCH v1] net/i40e: remove redundant number of packets
> >>>> check
> >>>>
> >>>> For i40e_xmit_pkts_vec_xx function, it checks nb_pkts to ensure
> >>>> nb_pkts does not cross rs_thresh.
> >>>>
> >>>> However, in i40e_xmit_fixed_burst_vec_xx function, this check will
> >>>> be performed again. To improve code, delete this redundant check.
> >>>>
> >>>> Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> >>>> Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
> >>>> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> >>>
> >>> Applied to dpdk-next-net-intel.
> >>>
> >>
> >> Hi Qi,
> >>
> >> This patch is not acked by the i40e maintainers.
> >>
> >> And this is changing the datapath for the -rc3, two weeks before the
> >> release. Is it tested enough?
> >>
> >> What is the gain with this patch, I don't see any numbers in the commit log.
> >> If the gain is small, can we postpone this patch to next release
> >> instead of getting it for -rc3?
> >
> > The patch applied the same thing as below which I have reviewed.
> > https://patchwork.dpdk.org/project/dpdk/patch/20220222224818.8612-1-
> ka
> > thleen.capella@arm.com/
> >
> > I didn't see the risk of having it, and I will add a "reviewed-by" to avoid
> confusion, but if you think it's risky, we can still defer it to next-net.
> >
> 
> Code change looks simple, but risk is more theoretical to get a datapath code
> optimization close to the release, and Feifei reported that there is no visible
> performance gain.
> So I think safer to postpone to next release if you don't object.

Re-applied to dpdk-next-net-intel.

Thanks
Qi

RE: [PATCH v1] net/i40e: remove redundant number of packets check

[Zhang, Qi Z]

> -----Original Message-----
> From: Feifei Wang <feifei.wang2@arm.com>
> Sent: Thursday, March 3, 2022 9:54 AM
> To: Xing, Beilei <beilei.xing@intel.com>; David Christensen
> <drc@linux.vnet.ibm.com>; Richardson, Bruce <bruce.richardson@intel.com>;
> Ananyev, Konstantin <konstantin.ananyev@intel.com>; Ruifeng Wang
> <ruifeng.wang@arm.com>
> Cc: dev@dpdk.org; nd@arm.com; Feifei Wang <feifei.wang2@arm.com>;
> Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> Subject: [PATCH v1] net/i40e: remove redundant number of packets check
> 
> For i40e_xmit_pkts_vec_xx function, it checks nb_pkts to ensure nb_pkts does
> not cross rs_thresh.
> 
> However, in i40e_xmit_fixed_burst_vec_xx function, this check will be
> performed again. To improve code, delete this redundant check.
> 
> Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>

Reviewed-by: Qi Zhang <qi.z.zhang@intel.com>

Applied to dpdk-next-net-intel.

Thanks
Qi