* [dpdk-dev] [PATCH] net/thunderx: Block sq door writes on zero pkts
@ 2018-07-11 7:22 Kiran Kumar
2018-07-11 7:37 ` Jerin Jacob
2018-07-11 8:24 ` [dpdk-dev] [PATCH v2] net/thunderx: avoid sq door bell writes on zero packets Kiran Kumar
0 siblings, 2 replies; 5+ messages in thread
From: Kiran Kumar @ 2018-07-11 7:22 UTC (permalink / raw)
To: dev; +Cc: jerin.jacob, maciej.czekaj, Kiran Kumar
With current code, we are performing sq door writes even with 0 pkts.
this will create pressure on register bus. This patch will block these
writes.
Fixes: 1c421f18e0 ("net/thunderx: add single and multi-segment Tx")
Signed-off-by: Kiran Kumar <kkokkilagadda@caviumnetworks.com>
---
drivers/net/thunderx/nicvf_rxtx.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/net/thunderx/nicvf_rxtx.c b/drivers/net/thunderx/nicvf_rxtx.c
index 72305d9..8075a8e 100644
--- a/drivers/net/thunderx/nicvf_rxtx.c
+++ b/drivers/net/thunderx/nicvf_rxtx.c
@@ -162,12 +162,14 @@ nicvf_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
free_desc -= TX_DESC_PER_PKT;
}
- sq->tail = tail;
- sq->xmit_bufs += i;
- rte_wmb();
+ if (likely(i)) {
+ sq->tail = tail;
+ sq->xmit_bufs += i;
+ rte_wmb();
- /* Inform HW to xmit the packets */
- nicvf_addr_write(sq->sq_door, i * TX_DESC_PER_PKT);
+ /* Inform HW to xmit the packets */
+ nicvf_addr_write(sq->sq_door, i * TX_DESC_PER_PKT);
+ }
return i;
}
--
2.7.4
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [dpdk-dev] [PATCH] net/thunderx: Block sq door writes on zero pkts
2018-07-11 7:22 [dpdk-dev] [PATCH] net/thunderx: Block sq door writes on zero pkts Kiran Kumar
@ 2018-07-11 7:37 ` Jerin Jacob
2018-07-11 8:24 ` [dpdk-dev] [PATCH v2] net/thunderx: avoid sq door bell writes on zero packets Kiran Kumar
1 sibling, 0 replies; 5+ messages in thread
From: Jerin Jacob @ 2018-07-11 7:37 UTC (permalink / raw)
To: Kiran Kumar; +Cc: dev, maciej.czekaj
-----Original Message-----
> Date: Wed, 11 Jul 2018 12:52:03 +0530
> From: Kiran Kumar <kkokkilagadda@caviumnetworks.com>
> To: dev@dpdk.org
> Cc: jerin.jacob@caviumnetworks.com, maciej.czekaj@caviumnetworks.com, Kiran
> Kumar <kkokkilagadda@caviumnetworks.com>
> Subject: [dpdk-dev] [PATCH] net/thunderx: Block sq door writes on zero pkts
> X-Mailer: git-send-email 2.7.4
Use small letter to start the comment.(s/Block/block)
I think, we can change the subject to "avoid sq door bell writes on zero packet"
>
> With current code, we are performing sq door writes even with 0 pkts.
> this will create pressure on register bus. This patch will block these
> writes.
Could rename to:
Avoid sq door bell write on zero packet case to reduce additional traffic
on register bus.
>
> Fixes: 1c421f18e0 ("net/thunderx: add single and multi-segment Tx")
add
Cc: stable@dpdk.org
>
> Signed-off-by: Kiran Kumar <kkokkilagadda@caviumnetworks.com>
> ---
> drivers/net/thunderx/nicvf_rxtx.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/thunderx/nicvf_rxtx.c b/drivers/net/thunderx/nicvf_rxtx.c
> index 72305d9..8075a8e 100644
> --- a/drivers/net/thunderx/nicvf_rxtx.c
> +++ b/drivers/net/thunderx/nicvf_rxtx.c
> @@ -162,12 +162,14 @@ nicvf_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
> free_desc -= TX_DESC_PER_PKT;
> }
>
> - sq->tail = tail;
> - sq->xmit_bufs += i;
> - rte_wmb();
> + if (likely(i)) {
> + sq->tail = tail;
> + sq->xmit_bufs += i;
> + rte_wmb();
>
> - /* Inform HW to xmit the packets */
> - nicvf_addr_write(sq->sq_door, i * TX_DESC_PER_PKT);
> + /* Inform HW to xmit the packets */
> + nicvf_addr_write(sq->sq_door, i * TX_DESC_PER_PKT);
> + }
Please add same logic for nicvf_xmit_pkts_multiseg function.
With above changes:
Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
> return i;
> }
>
> --
> 2.7.4
>
^ permalink raw reply [flat|nested] 5+ messages in thread* [dpdk-dev] [PATCH v2] net/thunderx: avoid sq door bell writes on zero packets
2018-07-11 7:22 [dpdk-dev] [PATCH] net/thunderx: Block sq door writes on zero pkts Kiran Kumar
2018-07-11 7:37 ` Jerin Jacob
@ 2018-07-11 8:24 ` Kiran Kumar
2018-07-11 9:05 ` Jerin Jacob
1 sibling, 1 reply; 5+ messages in thread
From: Kiran Kumar @ 2018-07-11 8:24 UTC (permalink / raw)
To: jerin.jacob, maciej.czekaj, ferruh.yigit; +Cc: dev, Kiran Kumar, stable
Avoid sq door bell write on zero packet case to reduce additional
traffic on register bus.
Fixes: 1c421f18e0 ("net/thunderx: add single and multi-segment Tx")
Cc: stable@dpdk.org
Signed-off-by: Kiran Kumar <kkokkilagadda@caviumnetworks.com>
---
v2 Changes:
- changed summery and description.
- added same optimization to nicvf_xmit_pkts_multiseg
drivers/net/thunderx/nicvf_rxtx.c | 24 ++++++++++++++----------
1 file changed, 14 insertions(+), 10 deletions(-)
diff --git a/drivers/net/thunderx/nicvf_rxtx.c b/drivers/net/thunderx/nicvf_rxtx.c
index 72305d9..6e075e2 100644
--- a/drivers/net/thunderx/nicvf_rxtx.c
+++ b/drivers/net/thunderx/nicvf_rxtx.c
@@ -162,12 +162,14 @@ nicvf_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
free_desc -= TX_DESC_PER_PKT;
}
- sq->tail = tail;
- sq->xmit_bufs += i;
- rte_wmb();
+ if (likely(i)) {
+ sq->tail = tail;
+ sq->xmit_bufs += i;
+ rte_wmb();
- /* Inform HW to xmit the packets */
- nicvf_addr_write(sq->sq_door, i * TX_DESC_PER_PKT);
+ /* Inform HW to xmit the packets */
+ nicvf_addr_write(sq->sq_door, i * TX_DESC_PER_PKT);
+ }
return i;
}
@@ -218,12 +220,14 @@ nicvf_xmit_pkts_multiseg(void *tx_queue, struct rte_mbuf **tx_pkts,
}
}
- sq->tail = tail;
- sq->xmit_bufs += used_bufs;
- rte_wmb();
+ if (likely(used_desc)) {
+ sq->tail = tail;
+ sq->xmit_bufs += used_bufs;
+ rte_wmb();
- /* Inform HW to xmit the packets */
- nicvf_addr_write(sq->sq_door, used_desc);
+ /* Inform HW to xmit the packets */
+ nicvf_addr_write(sq->sq_door, used_desc);
+ }
return i;
}
--
2.7.4
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [dpdk-dev] [PATCH v2] net/thunderx: avoid sq door bell writes on zero packets
2018-07-11 8:24 ` [dpdk-dev] [PATCH v2] net/thunderx: avoid sq door bell writes on zero packets Kiran Kumar
@ 2018-07-11 9:05 ` Jerin Jacob
2018-07-18 9:41 ` Ferruh Yigit
0 siblings, 1 reply; 5+ messages in thread
From: Jerin Jacob @ 2018-07-11 9:05 UTC (permalink / raw)
To: Kiran Kumar; +Cc: maciej.czekaj, ferruh.yigit, dev, stable
-----Original Message-----
> Date: Wed, 11 Jul 2018 13:54:36 +0530
> From: Kiran Kumar <kkokkilagadda@caviumnetworks.com>
> To: jerin.jacob@caviumnetworks.com, maciej.czekaj@caviumnetworks.com,
> ferruh.yigit@intel.com
> Cc: dev@dpdk.org, Kiran Kumar <kkokkilagadda@caviumnetworks.com>,
> stable@dpdk.org
> Subject: [dpdk-dev] [PATCH v2] net/thunderx: avoid sq door bell writes on
> zero packets
> X-Mailer: git-send-email 2.7.4
>
> Avoid sq door bell write on zero packet case to reduce additional
> traffic on register bus.
>
> Fixes: 1c421f18e0 ("net/thunderx: add single and multi-segment Tx")
> Cc: stable@dpdk.org
>
> Signed-off-by: Kiran Kumar <kkokkilagadda@caviumnetworks.com>
Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
> ---
> v2 Changes:
> - changed summery and description.
> - added same optimization to nicvf_xmit_pkts_multiseg
>
> drivers/net/thunderx/nicvf_rxtx.c | 24 ++++++++++++++----------
> 1 file changed, 14 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/thunderx/nicvf_rxtx.c b/drivers/net/thunderx/nicvf_rxtx.c
> index 72305d9..6e075e2 100644
> --- a/drivers/net/thunderx/nicvf_rxtx.c
> +++ b/drivers/net/thunderx/nicvf_rxtx.c
> @@ -162,12 +162,14 @@ nicvf_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
> free_desc -= TX_DESC_PER_PKT;
> }
>
> - sq->tail = tail;
> - sq->xmit_bufs += i;
> - rte_wmb();
> + if (likely(i)) {
> + sq->tail = tail;
> + sq->xmit_bufs += i;
> + rte_wmb();
>
> - /* Inform HW to xmit the packets */
> - nicvf_addr_write(sq->sq_door, i * TX_DESC_PER_PKT);
> + /* Inform HW to xmit the packets */
> + nicvf_addr_write(sq->sq_door, i * TX_DESC_PER_PKT);
> + }
> return i;
> }
>
> @@ -218,12 +220,14 @@ nicvf_xmit_pkts_multiseg(void *tx_queue, struct rte_mbuf **tx_pkts,
> }
> }
>
> - sq->tail = tail;
> - sq->xmit_bufs += used_bufs;
> - rte_wmb();
> + if (likely(used_desc)) {
> + sq->tail = tail;
> + sq->xmit_bufs += used_bufs;
> + rte_wmb();
>
> - /* Inform HW to xmit the packets */
> - nicvf_addr_write(sq->sq_door, used_desc);
> + /* Inform HW to xmit the packets */
> + nicvf_addr_write(sq->sq_door, used_desc);
> + }
> return i;
> }
>
> --
> 2.7.4
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [dpdk-dev] [PATCH v2] net/thunderx: avoid sq door bell writes on zero packets
2018-07-11 9:05 ` Jerin Jacob
@ 2018-07-18 9:41 ` Ferruh Yigit
0 siblings, 0 replies; 5+ messages in thread
From: Ferruh Yigit @ 2018-07-18 9:41 UTC (permalink / raw)
To: Jerin Jacob, Kiran Kumar; +Cc: maciej.czekaj, dev, stable
On 7/11/2018 10:05 AM, Jerin Jacob wrote:
> -----Original Message-----
>> Date: Wed, 11 Jul 2018 13:54:36 +0530
>> From: Kiran Kumar <kkokkilagadda@caviumnetworks.com>
>> To: jerin.jacob@caviumnetworks.com, maciej.czekaj@caviumnetworks.com,
>> ferruh.yigit@intel.com
>> Cc: dev@dpdk.org, Kiran Kumar <kkokkilagadda@caviumnetworks.com>,
>> stable@dpdk.org
>> Subject: [dpdk-dev] [PATCH v2] net/thunderx: avoid sq door bell writes on
>> zero packets
>> X-Mailer: git-send-email 2.7.4
>>
>> Avoid sq door bell write on zero packet case to reduce additional
>> traffic on register bus.
>>
>> Fixes: 1c421f18e0 ("net/thunderx: add single and multi-segment Tx")
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Kiran Kumar <kkokkilagadda@caviumnetworks.com>
>
> Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Applied to dpdk-next-net/master, thanks.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2018-07-11 7:22 [dpdk-dev] [PATCH] net/thunderx: Block sq door writes on zero pkts Kiran Kumar
2018-07-11 7:37 ` Jerin Jacob
2018-07-11 8:24 ` [dpdk-dev] [PATCH v2] net/thunderx: avoid sq door bell writes on zero packets Kiran Kumar
2018-07-11 9:05 ` Jerin Jacob
2018-07-18 9:41 ` Ferruh Yigit
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