diff mbox series

[v2] net/i40e: remove redundant judgment

Message ID 20230328072828.386576-1-feifei.wang2@arm.com (mailing list archive)
State Accepted, archived
Delegated to: Qi Zhang
Headers
Series [v2] net/i40e: remove redundant judgment |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/loongarch-compilation success Compilation OK
ci/loongarch-unit-testing success Unit Testing PASS
ci/github-robot: build success github build: passed
ci/iol-broadcom-Functional success Functional Testing PASS
ci/iol-mellanox-Performance success Performance Testing PASS
ci/iol-broadcom-Performance success Performance Testing PASS
ci/iol-intel-Performance success Performance Testing PASS
ci/iol-intel-Functional success Functional Testing PASS
ci/iol-abi-testing success Testing PASS
ci/iol-unit-testing success Testing PASS
ci/iol-aarch64-unit-testing success Testing PASS
ci/iol-testing success Testing PASS
ci/iol-x86_64-unit-testing success Testing PASS
ci/iol-x86_64-compile-testing success Testing PASS
ci/iol-aarch64-compile-testing success Testing PASS
ci/Intel-compilation success Compilation OK
ci/intel-Testing success Testing PASS
ci/intel-Functional success Functional PASS

Commit Message

Feifei Wang March 28, 2023, 7:28 a.m. UTC 
  Merged variable updates under the same condition. It reduces branch.

In ampere-altra, there is no performance improvement with this patch.
In x86 sse and avx2 path, there is also no performance improvement.


v2:
1. add change for avx and altivec path.

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_common_avx.h  | 9 +++++----
 drivers/net/i40e/i40e_rxtx_vec_altivec.c | 9 +++++----
 drivers/net/i40e/i40e_rxtx_vec_neon.c    | 9 +++++----
 drivers/net/i40e/i40e_rxtx_vec_sse.c     | 9 +++++----
 4 files changed, 20 insertions(+), 16 deletions(-)

Comments

Qi Zhang April 27, 2023, 7:37 a.m. UTC | #1 
> -----Original Message-----
> From: Feifei Wang <feifei.wang2@arm.com>
> Sent: Tuesday, March 28, 2023 3:28 PM
> To: Richardson, Bruce <bruce.richardson@intel.com>; Konstantin Ananyev
> <konstantin.v.ananyev@yandex.ru>; Zhang, Yuying
> <yuying.zhang@intel.com>; Xing, Beilei <beilei.xing@intel.com>; David
> Christensen <drc@linux.vnet.ibm.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 v2] net/i40e: remove redundant judgment
> 
> Merged variable updates under the same condition. It reduces branch.
> 
> In ampere-altra, there is no performance improvement with this patch.
> In x86 sse and avx2 path, there is also no performance improvement.

Thanks for sharing the results. While the code implements some best practices, such as reducing branching and adding compiler hints, which should generally improve performance, it's not necessary to highlight that it didn't provide benefits on certain specific platforms.

Would it be ok to remove the last two lines when merging the patch?

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


> 
> 
> v2:
> 1. add change for avx and altivec path.
> 
> 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_common_avx.h  | 9 +++++----
> drivers/net/i40e/i40e_rxtx_vec_altivec.c | 9 +++++----
>  drivers/net/i40e/i40e_rxtx_vec_neon.c    | 9 +++++----
>  drivers/net/i40e/i40e_rxtx_vec_sse.c     | 9 +++++----
>  4 files changed, 20 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/net/i40e/i40e_rxtx_common_avx.h
> b/drivers/net/i40e/i40e_rxtx_common_avx.h
> index cfc1e63173..85958d6c81 100644
> --- a/drivers/net/i40e/i40e_rxtx_common_avx.h
> +++ b/drivers/net/i40e/i40e_rxtx_common_avx.h
> @@ -198,14 +198,15 @@ i40e_rxq_rearm_common(struct i40e_rx_queue
> *rxq, __rte_unused bool avx512)  #endif
> 
>  	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
> -	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
> +	rx_id = rxq->rxrearm_start - 1;
> +
> +	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
>  		rxq->rxrearm_start = 0;
> +		rx_id = rxq->nb_rx_desc - 1;
> +	}
> 
>  	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
> 
> -	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
> -			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
> -
>  	/* Update the tail pointer on the NIC */
>  	I40E_PCI_REG_WC_WRITE(rxq->qrx_tail, rx_id);  } diff --git
> a/drivers/net/i40e/i40e_rxtx_vec_altivec.c
> b/drivers/net/i40e/i40e_rxtx_vec_altivec.c
> index 2dfa04599c..8672ad1c41 100644
> --- a/drivers/net/i40e/i40e_rxtx_vec_altivec.c
> +++ b/drivers/net/i40e/i40e_rxtx_vec_altivec.c
> @@ -89,14 +89,15 @@ i40e_rxq_rearm(struct i40e_rx_queue *rxq)
>  	}
> 
>  	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
> -	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
> +	rx_id = rxq->rxrearm_start - 1;
> +
> +	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
>  		rxq->rxrearm_start = 0;
> +		rx_id = rxq->nb_rx_desc - 1;
> +	}
> 
>  	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
> 
> -	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
> -			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
> -
>  	/* Update the tail pointer on the NIC */
>  	I40E_PCI_REG_WRITE(rxq->qrx_tail, rx_id);  } diff --git
> a/drivers/net/i40e/i40e_rxtx_vec_neon.c
> b/drivers/net/i40e/i40e_rxtx_vec_neon.c
> index 12e6f1cbcb..49391fe4c7 100644
> --- a/drivers/net/i40e/i40e_rxtx_vec_neon.c
> +++ b/drivers/net/i40e/i40e_rxtx_vec_neon.c
> @@ -64,14 +64,15 @@ i40e_rxq_rearm(struct i40e_rx_queue *rxq)
>  	}
> 
>  	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
> -	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
> +	rx_id = rxq->rxrearm_start - 1;
> +
> +	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
>  		rxq->rxrearm_start = 0;
> +		rx_id = rxq->nb_rx_desc - 1;
> +	}
> 
>  	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
> 
> -	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
> -			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
> -
>  	rte_io_wmb();
>  	/* Update the tail pointer on the NIC */
>  	I40E_PCI_REG_WRITE_RELAXED(rxq->qrx_tail, rx_id); diff --git
> a/drivers/net/i40e/i40e_rxtx_vec_sse.c
> b/drivers/net/i40e/i40e_rxtx_vec_sse.c
> index bdc979a839..baf83cb3df 100644
> --- a/drivers/net/i40e/i40e_rxtx_vec_sse.c
> +++ b/drivers/net/i40e/i40e_rxtx_vec_sse.c
> @@ -77,14 +77,15 @@ i40e_rxq_rearm(struct i40e_rx_queue *rxq)
>  	}
> 
>  	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
> -	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
> +	rx_id = rxq->rxrearm_start - 1;
> +
> +	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
>  		rxq->rxrearm_start = 0;
> +		rx_id = rxq->nb_rx_desc - 1;
> +	}
> 
>  	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
> 
> -	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
> -			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
> -
>  	/* Update the tail pointer on the NIC */
>  	I40E_PCI_REG_WC_WRITE(rxq->qrx_tail, rx_id);  }
> --
> 2.25.1
Qi Zhang May 15, 2023, 1:59 a.m. UTC | #2 
> -----Original Message-----
> From: Zhang, Qi Z <qi.z.zhang@intel.com>
> Sent: Thursday, April 27, 2023 3:38 PM
> To: Feifei Wang <feifei.wang2@arm.com>; Richardson, Bruce
> <bruce.richardson@intel.com>; Konstantin Ananyev
> <konstantin.v.ananyev@yandex.ru>; Zhang, Yuying
> <yuying.zhang@intel.com>; Xing, Beilei <beilei.xing@intel.com>; David
> Christensen <drc@linux.vnet.ibm.com>; Ruifeng Wang
> <ruifeng.wang@arm.com>
> Cc: dev@dpdk.org; nd@arm.com; Honnappa Nagarahalli
> <honnappa.nagarahalli@arm.com>
> Subject: RE: [PATCH v2] net/i40e: remove redundant judgment
> 
> 
> 
> > -----Original Message-----
> > From: Feifei Wang <feifei.wang2@arm.com>
> > Sent: Tuesday, March 28, 2023 3:28 PM
> > To: Richardson, Bruce <bruce.richardson@intel.com>; Konstantin Ananyev
> > <konstantin.v.ananyev@yandex.ru>; Zhang, Yuying
> > <yuying.zhang@intel.com>; Xing, Beilei <beilei.xing@intel.com>; David
> > Christensen <drc@linux.vnet.ibm.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 v2] net/i40e: remove redundant judgment
> >
> > Merged variable updates under the same condition. It reduces branch.
> >
> > In ampere-altra, there is no performance improvement with this patch.
> > In x86 sse and avx2 path, there is also no performance improvement.
> 
> Thanks for sharing the results. While the code implements some best
> practices, such as reducing branching and adding compiler hints, which
> should generally improve performance, it's not necessary to highlight that it
> didn't provide benefits on certain specific platforms.
> 
> Would it be ok to remove the last two lines when merging the patch?

Ping

> 
> Otherwise
> Acked-by: Qi Zhang <qi.z.zhang@intel.com>
> 
> 
> >
> >
> > v2:
> > 1. add change for avx and altivec path.
> >
> > 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_common_avx.h  | 9 +++++----
> > drivers/net/i40e/i40e_rxtx_vec_altivec.c | 9 +++++----
> >  drivers/net/i40e/i40e_rxtx_vec_neon.c    | 9 +++++----
> >  drivers/net/i40e/i40e_rxtx_vec_sse.c     | 9 +++++----
> >  4 files changed, 20 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/net/i40e/i40e_rxtx_common_avx.h
> > b/drivers/net/i40e/i40e_rxtx_common_avx.h
> > index cfc1e63173..85958d6c81 100644
> > --- a/drivers/net/i40e/i40e_rxtx_common_avx.h
> > +++ b/drivers/net/i40e/i40e_rxtx_common_avx.h
> > @@ -198,14 +198,15 @@ i40e_rxq_rearm_common(struct i40e_rx_queue
> *rxq,
> > __rte_unused bool avx512)  #endif
> >
> >  	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
> > -	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
> > +	rx_id = rxq->rxrearm_start - 1;
> > +
> > +	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
> >  		rxq->rxrearm_start = 0;
> > +		rx_id = rxq->nb_rx_desc - 1;
> > +	}
> >
> >  	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
> >
> > -	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
> > -			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
> > -
> >  	/* Update the tail pointer on the NIC */
> >  	I40E_PCI_REG_WC_WRITE(rxq->qrx_tail, rx_id);  } diff --git
> > a/drivers/net/i40e/i40e_rxtx_vec_altivec.c
> > b/drivers/net/i40e/i40e_rxtx_vec_altivec.c
> > index 2dfa04599c..8672ad1c41 100644
> > --- a/drivers/net/i40e/i40e_rxtx_vec_altivec.c
> > +++ b/drivers/net/i40e/i40e_rxtx_vec_altivec.c
> > @@ -89,14 +89,15 @@ i40e_rxq_rearm(struct i40e_rx_queue *rxq)
> >  	}
> >
> >  	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
> > -	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
> > +	rx_id = rxq->rxrearm_start - 1;
> > +
> > +	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
> >  		rxq->rxrearm_start = 0;
> > +		rx_id = rxq->nb_rx_desc - 1;
> > +	}
> >
> >  	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
> >
> > -	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
> > -			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
> > -
> >  	/* Update the tail pointer on the NIC */
> >  	I40E_PCI_REG_WRITE(rxq->qrx_tail, rx_id);  } diff --git
> > a/drivers/net/i40e/i40e_rxtx_vec_neon.c
> > b/drivers/net/i40e/i40e_rxtx_vec_neon.c
> > index 12e6f1cbcb..49391fe4c7 100644
> > --- a/drivers/net/i40e/i40e_rxtx_vec_neon.c
> > +++ b/drivers/net/i40e/i40e_rxtx_vec_neon.c
> > @@ -64,14 +64,15 @@ i40e_rxq_rearm(struct i40e_rx_queue *rxq)
> >  	}
> >
> >  	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
> > -	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
> > +	rx_id = rxq->rxrearm_start - 1;
> > +
> > +	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
> >  		rxq->rxrearm_start = 0;
> > +		rx_id = rxq->nb_rx_desc - 1;
> > +	}
> >
> >  	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
> >
> > -	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
> > -			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
> > -
> >  	rte_io_wmb();
> >  	/* Update the tail pointer on the NIC */
> >  	I40E_PCI_REG_WRITE_RELAXED(rxq->qrx_tail, rx_id); diff --git
> > a/drivers/net/i40e/i40e_rxtx_vec_sse.c
> > b/drivers/net/i40e/i40e_rxtx_vec_sse.c
> > index bdc979a839..baf83cb3df 100644
> > --- a/drivers/net/i40e/i40e_rxtx_vec_sse.c
> > +++ b/drivers/net/i40e/i40e_rxtx_vec_sse.c
> > @@ -77,14 +77,15 @@ i40e_rxq_rearm(struct i40e_rx_queue *rxq)
> >  	}
> >
> >  	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
> > -	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
> > +	rx_id = rxq->rxrearm_start - 1;
> > +
> > +	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
> >  		rxq->rxrearm_start = 0;
> > +		rx_id = rxq->nb_rx_desc - 1;
> > +	}
> >
> >  	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
> >
> > -	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
> > -			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
> > -
> >  	/* Update the tail pointer on the NIC */
> >  	I40E_PCI_REG_WC_WRITE(rxq->qrx_tail, rx_id);  }
> > --
> > 2.25.1
Feifei Wang May 16, 2023, 1:54 a.m. UTC | #3 
> -----Original Message-----
> From: Zhang, Qi Z <qi.z.zhang@intel.com>
> Sent: Monday, May 15, 2023 9:59 AM
> To: Zhang, Qi Z <qi.z.zhang@intel.com>; Feifei Wang
> <Feifei.Wang2@arm.com>; Richardson, Bruce <bruce.richardson@intel.com>;
> Konstantin Ananyev <konstantin.v.ananyev@yandex.ru>; Zhang, Yuying
> <yuying.zhang@intel.com>; Xing, Beilei <beilei.xing@intel.com>; David
> Christensen <drc@linux.vnet.ibm.com>; Ruifeng Wang
> <Ruifeng.Wang@arm.com>
> Cc: dev@dpdk.org; nd <nd@arm.com>; Honnappa Nagarahalli
> <Honnappa.Nagarahalli@arm.com>
> Subject: RE: [PATCH v2] net/i40e: remove redundant judgment
> 
> 
> 
> > -----Original Message-----
> > From: Zhang, Qi Z <qi.z.zhang@intel.com>
> > Sent: Thursday, April 27, 2023 3:38 PM
> > To: Feifei Wang <feifei.wang2@arm.com>; Richardson, Bruce
> > <bruce.richardson@intel.com>; Konstantin Ananyev
> > <konstantin.v.ananyev@yandex.ru>; Zhang, Yuying
> > <yuying.zhang@intel.com>; Xing, Beilei <beilei.xing@intel.com>; David
> > Christensen <drc@linux.vnet.ibm.com>; Ruifeng Wang
> > <ruifeng.wang@arm.com>
> > Cc: dev@dpdk.org; nd@arm.com; Honnappa Nagarahalli
> > <honnappa.nagarahalli@arm.com>
> > Subject: RE: [PATCH v2] net/i40e: remove redundant judgment
> >
> >
> >
> > > -----Original Message-----
> > > From: Feifei Wang <feifei.wang2@arm.com>
> > > Sent: Tuesday, March 28, 2023 3:28 PM
> > > To: Richardson, Bruce <bruce.richardson@intel.com>; Konstantin
> > > Ananyev <konstantin.v.ananyev@yandex.ru>; Zhang, Yuying
> > > <yuying.zhang@intel.com>; Xing, Beilei <beilei.xing@intel.com>;
> > > David Christensen <drc@linux.vnet.ibm.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 v2] net/i40e: remove redundant judgment
> > >
> > > Merged variable updates under the same condition. It reduces branch.
> > >
> > > In ampere-altra, there is no performance improvement with this patch.
> > > In x86 sse and avx2 path, there is also no performance improvement.
> >
> > Thanks for sharing the results. While the code implements some best
> > practices, such as reducing branching and adding compiler hints, which
> > should generally improve performance, it's not necessary to highlight
> > that it didn't provide benefits on certain specific platforms.
> >
> > Would it be ok to remove the last two lines when merging the patch?
> 
> Ping
> 
Sorry for I did not reply this. I agree with this when  merging the patch.
Thanks for the comments~.
> >
> > Otherwise
> > Acked-by: Qi Zhang <qi.z.zhang@intel.com>
> >
> >
> > >
> > >
> > > v2:
> > > 1. add change for avx and altivec path.
> > >
> > > 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_common_avx.h  | 9 +++++----
> > > drivers/net/i40e/i40e_rxtx_vec_altivec.c | 9 +++++----
> > >  drivers/net/i40e/i40e_rxtx_vec_neon.c    | 9 +++++----
> > >  drivers/net/i40e/i40e_rxtx_vec_sse.c     | 9 +++++----
> > >  4 files changed, 20 insertions(+), 16 deletions(-)
> > >
> > > diff --git a/drivers/net/i40e/i40e_rxtx_common_avx.h
> > > b/drivers/net/i40e/i40e_rxtx_common_avx.h
> > > index cfc1e63173..85958d6c81 100644
> > > --- a/drivers/net/i40e/i40e_rxtx_common_avx.h
> > > +++ b/drivers/net/i40e/i40e_rxtx_common_avx.h
> > > @@ -198,14 +198,15 @@ i40e_rxq_rearm_common(struct
> i40e_rx_queue
> > *rxq,
> > > __rte_unused bool avx512)  #endif
> > >
> > >  	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
> > > -	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
> > > +	rx_id = rxq->rxrearm_start - 1;
> > > +
> > > +	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
> > >  		rxq->rxrearm_start = 0;
> > > +		rx_id = rxq->nb_rx_desc - 1;
> > > +	}
> > >
> > >  	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
> > >
> > > -	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
> > > -			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
> > > -
> > >  	/* Update the tail pointer on the NIC */
> > >  	I40E_PCI_REG_WC_WRITE(rxq->qrx_tail, rx_id);  } diff --git
> > > a/drivers/net/i40e/i40e_rxtx_vec_altivec.c
> > > b/drivers/net/i40e/i40e_rxtx_vec_altivec.c
> > > index 2dfa04599c..8672ad1c41 100644
> > > --- a/drivers/net/i40e/i40e_rxtx_vec_altivec.c
> > > +++ b/drivers/net/i40e/i40e_rxtx_vec_altivec.c
> > > @@ -89,14 +89,15 @@ i40e_rxq_rearm(struct i40e_rx_queue *rxq)
> > >  	}
> > >
> > >  	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
> > > -	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
> > > +	rx_id = rxq->rxrearm_start - 1;
> > > +
> > > +	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
> > >  		rxq->rxrearm_start = 0;
> > > +		rx_id = rxq->nb_rx_desc - 1;
> > > +	}
> > >
> > >  	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
> > >
> > > -	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
> > > -			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
> > > -
> > >  	/* Update the tail pointer on the NIC */
> > >  	I40E_PCI_REG_WRITE(rxq->qrx_tail, rx_id);  } diff --git
> > > a/drivers/net/i40e/i40e_rxtx_vec_neon.c
> > > b/drivers/net/i40e/i40e_rxtx_vec_neon.c
> > > index 12e6f1cbcb..49391fe4c7 100644
> > > --- a/drivers/net/i40e/i40e_rxtx_vec_neon.c
> > > +++ b/drivers/net/i40e/i40e_rxtx_vec_neon.c
> > > @@ -64,14 +64,15 @@ i40e_rxq_rearm(struct i40e_rx_queue *rxq)
> > >  	}
> > >
> > >  	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
> > > -	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
> > > +	rx_id = rxq->rxrearm_start - 1;
> > > +
> > > +	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
> > >  		rxq->rxrearm_start = 0;
> > > +		rx_id = rxq->nb_rx_desc - 1;
> > > +	}
> > >
> > >  	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
> > >
> > > -	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
> > > -			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
> > > -
> > >  	rte_io_wmb();
> > >  	/* Update the tail pointer on the NIC */
> > >  	I40E_PCI_REG_WRITE_RELAXED(rxq->qrx_tail, rx_id); diff --git
> > > a/drivers/net/i40e/i40e_rxtx_vec_sse.c
> > > b/drivers/net/i40e/i40e_rxtx_vec_sse.c
> > > index bdc979a839..baf83cb3df 100644
> > > --- a/drivers/net/i40e/i40e_rxtx_vec_sse.c
> > > +++ b/drivers/net/i40e/i40e_rxtx_vec_sse.c
> > > @@ -77,14 +77,15 @@ i40e_rxq_rearm(struct i40e_rx_queue *rxq)
> > >  	}
> > >
> > >  	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
> > > -	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
> > > +	rx_id = rxq->rxrearm_start - 1;
> > > +
> > > +	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
> > >  		rxq->rxrearm_start = 0;
> > > +		rx_id = rxq->nb_rx_desc - 1;
> > > +	}
> > >
> > >  	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
> > >
> > > -	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
> > > -			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
> > > -
> > >  	/* Update the tail pointer on the NIC */
> > >  	I40E_PCI_REG_WC_WRITE(rxq->qrx_tail, rx_id);  }
> > > --
> > > 2.25.1
Qi Zhang May 17, 2023, 2:25 a.m. UTC | #4 
> -----Original Message-----
> From: Feifei Wang <Feifei.Wang2@arm.com>
> Sent: Tuesday, May 16, 2023 9:54 AM
> To: Zhang, Qi Z <qi.z.zhang@intel.com>; Richardson, Bruce
> <bruce.richardson@intel.com>; Konstantin Ananyev
> <konstantin.v.ananyev@yandex.ru>; Zhang, Yuying
> <yuying.zhang@intel.com>; Xing, Beilei <beilei.xing@intel.com>; David
> Christensen <drc@linux.vnet.ibm.com>; Ruifeng Wang
> <Ruifeng.Wang@arm.com>
> Cc: dev@dpdk.org; nd <nd@arm.com>; Honnappa Nagarahalli
> <Honnappa.Nagarahalli@arm.com>; nd <nd@arm.com>
> Subject: RE: [PATCH v2] net/i40e: remove redundant judgment
> 
> > -----Original Message-----
> > From: Zhang, Qi Z <qi.z.zhang@intel.com>
> > Sent: Monday, May 15, 2023 9:59 AM
> > To: Zhang, Qi Z <qi.z.zhang@intel.com>; Feifei Wang
> > <Feifei.Wang2@arm.com>; Richardson, Bruce
> > <bruce.richardson@intel.com>; Konstantin Ananyev
> > <konstantin.v.ananyev@yandex.ru>; Zhang, Yuying
> > <yuying.zhang@intel.com>; Xing, Beilei <beilei.xing@intel.com>; David
> > Christensen <drc@linux.vnet.ibm.com>; Ruifeng Wang
> > <Ruifeng.Wang@arm.com>
> > Cc: dev@dpdk.org; nd <nd@arm.com>; Honnappa Nagarahalli
> > <Honnappa.Nagarahalli@arm.com>
> > Subject: RE: [PATCH v2] net/i40e: remove redundant judgment
> >
> >
> >
> > > -----Original Message-----
> > > From: Zhang, Qi Z <qi.z.zhang@intel.com>
> > > Sent: Thursday, April 27, 2023 3:38 PM
> > > To: Feifei Wang <feifei.wang2@arm.com>; Richardson, Bruce
> > > <bruce.richardson@intel.com>; Konstantin Ananyev
> > > <konstantin.v.ananyev@yandex.ru>; Zhang, Yuying
> > > <yuying.zhang@intel.com>; Xing, Beilei <beilei.xing@intel.com>;
> > > David Christensen <drc@linux.vnet.ibm.com>; Ruifeng Wang
> > > <ruifeng.wang@arm.com>
> > > Cc: dev@dpdk.org; nd@arm.com; Honnappa Nagarahalli
> > > <honnappa.nagarahalli@arm.com>
> > > Subject: RE: [PATCH v2] net/i40e: remove redundant judgment
> > >
> > >
> > >
> > > > -----Original Message-----
> > > > From: Feifei Wang <feifei.wang2@arm.com>
> > > > Sent: Tuesday, March 28, 2023 3:28 PM
> > > > To: Richardson, Bruce <bruce.richardson@intel.com>; Konstantin
> > > > Ananyev <konstantin.v.ananyev@yandex.ru>; Zhang, Yuying
> > > > <yuying.zhang@intel.com>; Xing, Beilei <beilei.xing@intel.com>;
> > > > David Christensen <drc@linux.vnet.ibm.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 v2] net/i40e: remove redundant judgment
> > > >
> > > > Merged variable updates under the same condition. It reduces branch.
> > > >
> > > > In ampere-altra, there is no performance improvement with this patch.
> > > > In x86 sse and avx2 path, there is also no performance improvement.
> > >
> > > Thanks for sharing the results. While the code implements some best
> > > practices, such as reducing branching and adding compiler hints,
> > > which should generally improve performance, it's not necessary to
> > > highlight that it didn't provide benefits on certain specific platforms.
> > >
> > > Would it be ok to remove the last two lines when merging the patch?
> >
> > Ping
> >
> Sorry for I did not reply this. I agree with this when  merging the patch.
> Thanks for the comments~.
> > >
> > > Otherwise
> > > Acked-by: Qi Zhang <qi.z.zhang@intel.com>

Applied to dpdk-next-net-intel.

Thanks
Qi
diff mbox series

Patch

diff --git a/drivers/net/i40e/i40e_rxtx_common_avx.h b/drivers/net/i40e/i40e_rxtx_common_avx.h
index cfc1e63173..85958d6c81 100644
--- a/drivers/net/i40e/i40e_rxtx_common_avx.h
+++ b/drivers/net/i40e/i40e_rxtx_common_avx.h
@@ -198,14 +198,15 @@  i40e_rxq_rearm_common(struct i40e_rx_queue *rxq, __rte_unused bool avx512)
 #endif
 
 	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
-	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
+	rx_id = rxq->rxrearm_start - 1;
+
+	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
 		rxq->rxrearm_start = 0;
+		rx_id = rxq->nb_rx_desc - 1;
+	}
 
 	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
 
-	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
-			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
-
 	/* Update the tail pointer on the NIC */
 	I40E_PCI_REG_WC_WRITE(rxq->qrx_tail, rx_id);
 }
diff --git a/drivers/net/i40e/i40e_rxtx_vec_altivec.c b/drivers/net/i40e/i40e_rxtx_vec_altivec.c
index 2dfa04599c..8672ad1c41 100644
--- a/drivers/net/i40e/i40e_rxtx_vec_altivec.c
+++ b/drivers/net/i40e/i40e_rxtx_vec_altivec.c
@@ -89,14 +89,15 @@  i40e_rxq_rearm(struct i40e_rx_queue *rxq)
 	}
 
 	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
-	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
+	rx_id = rxq->rxrearm_start - 1;
+
+	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
 		rxq->rxrearm_start = 0;
+		rx_id = rxq->nb_rx_desc - 1;
+	}
 
 	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
 
-	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
-			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
-
 	/* Update the tail pointer on the NIC */
 	I40E_PCI_REG_WRITE(rxq->qrx_tail, rx_id);
 }
diff --git a/drivers/net/i40e/i40e_rxtx_vec_neon.c b/drivers/net/i40e/i40e_rxtx_vec_neon.c
index 12e6f1cbcb..49391fe4c7 100644
--- a/drivers/net/i40e/i40e_rxtx_vec_neon.c
+++ b/drivers/net/i40e/i40e_rxtx_vec_neon.c
@@ -64,14 +64,15 @@  i40e_rxq_rearm(struct i40e_rx_queue *rxq)
 	}
 
 	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
-	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
+	rx_id = rxq->rxrearm_start - 1;
+
+	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
 		rxq->rxrearm_start = 0;
+		rx_id = rxq->nb_rx_desc - 1;
+	}
 
 	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
 
-	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
-			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
-
 	rte_io_wmb();
 	/* Update the tail pointer on the NIC */
 	I40E_PCI_REG_WRITE_RELAXED(rxq->qrx_tail, rx_id);
diff --git a/drivers/net/i40e/i40e_rxtx_vec_sse.c b/drivers/net/i40e/i40e_rxtx_vec_sse.c
index bdc979a839..baf83cb3df 100644
--- a/drivers/net/i40e/i40e_rxtx_vec_sse.c
+++ b/drivers/net/i40e/i40e_rxtx_vec_sse.c
@@ -77,14 +77,15 @@  i40e_rxq_rearm(struct i40e_rx_queue *rxq)
 	}
 
 	rxq->rxrearm_start += RTE_I40E_RXQ_REARM_THRESH;
-	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
+	rx_id = rxq->rxrearm_start - 1;
+
+	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
 		rxq->rxrearm_start = 0;
+		rx_id = rxq->nb_rx_desc - 1;
+	}
 
 	rxq->rxrearm_nb -= RTE_I40E_RXQ_REARM_THRESH;
 
-	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
-			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
-
 	/* Update the tail pointer on the NIC */
 	I40E_PCI_REG_WC_WRITE(rxq->qrx_tail, rx_id);
 }