* [dpdk-dev] [PATCH v2] ethdev: Prefetch driver variable structure
@ 2015-11-10 14:17 Polehn, Mike A
2015-11-10 17:03 ` Stephen Hemminger
0 siblings, 1 reply; 6+ messages in thread
From: Polehn, Mike A @ 2015-11-10 14:17 UTC (permalink / raw)
To: dev
Adds ethdev driver prefetch of variable structure to CPU cache 0
while calling into tx or rx device driver operation.
RFC 2544 test of NIC task test measurement points show improvement
of lower latency and/or better packet throughput indicating clock
cycles saved.
Signed-off-by: Mike A. Polehn <mike.a.polehn@intel.com>
---
lib/librte_ether/rte_ethdev.h | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
index 48a540d..f1c35de 100644
--- a/lib/librte_ether/rte_ethdev.h
+++ b/lib/librte_ether/rte_ethdev.h
@@ -2458,12 +2458,17 @@ rte_eth_rx_burst(uint8_t port_id, uint16_t queue_id,
struct rte_mbuf **rx_pkts, const uint16_t nb_pkts)
{
struct rte_eth_dev *dev;
+ int16_t nb_rx;
dev = &rte_eth_devices[port_id];
- int16_t nb_rx = (*dev->rx_pkt_burst)(dev->data->rx_queues[queue_id],
- rx_pkts, nb_pkts);
+ { /* limit scope of rxq variable */
+ /* rxq is going to be immediately used, prefetch it */
+ void *rxq = dev->data->rx_queues[queue_id];
+ rte_prefetch0(rxq);
+ nb_rx = (*dev->rx_pkt_burst)(rxq, rx_pkts, nb_pkts);
+ }
#ifdef RTE_ETHDEV_RXTX_CALLBACKS
struct rte_eth_rxtx_callback *cb = dev->post_rx_burst_cbs[queue_id];
@@ -2600,6 +2605,7 @@ rte_eth_tx_burst(uint8_t port_id, uint16_t queue_id,
struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
{
struct rte_eth_dev *dev;
+ void *txq;
dev = &rte_eth_devices[port_id];
@@ -2615,7 +2621,11 @@ rte_eth_tx_burst(uint8_t port_id, uint16_t queue_id,
}
#endif
- return (*dev->tx_pkt_burst)(dev->data->tx_queues[queue_id], tx_pkts, nb_pkts);
+ /* txq is going to be immediately used, prefetch it */
+ txq = dev->data->tx_queues[queue_id];
+ rte_prefetch0(txq);
+
+ return (*dev->tx_pkt_burst)(txq, tx_pkts, nb_pkts);
}
#endif
--
2.6.0
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [dpdk-dev] [PATCH v2] ethdev: Prefetch driver variable structure
2015-11-10 14:17 [dpdk-dev] [PATCH v2] ethdev: Prefetch driver variable structure Polehn, Mike A
@ 2015-11-10 17:03 ` Stephen Hemminger
2015-11-11 13:56 ` Polehn, Mike A
0 siblings, 1 reply; 6+ messages in thread
From: Stephen Hemminger @ 2015-11-10 17:03 UTC (permalink / raw)
To: Polehn, Mike A; +Cc: dev
On Tue, 10 Nov 2015 14:17:41 +0000
"Polehn, Mike A" <mike.a.polehn@intel.com> wrote:
> Adds ethdev driver prefetch of variable structure to CPU cache 0
> while calling into tx or rx device driver operation.
>
> RFC 2544 test of NIC task test measurement points show improvement
> of lower latency and/or better packet throughput indicating clock
> cycles saved.
>
> Signed-off-by: Mike A. Polehn <mike.a.polehn@intel.com>
Good idea, but lots of whitespace issues.
Please also check your mail client..
ERROR: patch seems to be corrupt (line wrapped?)
#80: FILE: lib/librte_ether/rte_ethdev.h:2457:
,
WARNING: please, no spaces at the start of a line
#84: FILE: lib/librte_ether/rte_ethdev.h:2460:
+ int16_t nb_rx;$
WARNING: please, no spaces at the start of a line
#89: FILE: lib/librte_ether/rte_ethdev.h:2462:
+ { /* limit scope of rxq variable */$
ERROR: code indent should use tabs where possible
#90: FILE: lib/librte_ether/rte_ethdev.h:2463:
+ /* rxq is going to be immediately used, prefetch it */$
ERROR: code indent should use tabs where possible
#91: FILE: lib/librte_ether/rte_ethdev.h:2464:
+ void *rxq =3D dev->data->rx_queues[queue_id];$
WARNING: please, no spaces at the start of a line
#91: FILE: lib/librte_ether/rte_ethdev.h:2464:
+ void *rxq =3D dev->data->rx_queues[queue_id];$
ERROR: spaces required around that '=' (ctx:WxV)
#91: FILE: lib/librte_ether/rte_ethdev.h:2464:
+ void *rxq =3D dev->data->rx_queues[queue_id];
^
ERROR: code indent should use tabs where possible
#92: FILE: lib/librte_ether/rte_ethdev.h:2465:
+ rte_prefetch0(rxq);$
WARNING: Missing a blank line after declarations
#92: FILE: lib/librte_ether/rte_ethdev.h:2465:
+ void *rxq =3D dev->data->rx_queues[queue_id];
+ rte_prefetch0(rxq);
WARNING: please, no spaces at the start of a line
#92: FILE: lib/librte_ether/rte_ethdev.h:2465:
+ rte_prefetch0(rxq);$
ERROR: code indent should use tabs where possible
#93: FILE: lib/librte_ether/rte_ethdev.h:2466:
+ nb_rx =3D (*dev->rx_pkt_burst)(rxq, rx_pkts, nb_pkts);$
WARNING: please, no spaces at the start of a line
#93: FILE: lib/librte_ether/rte_ethdev.h:2466:
+ nb_rx =3D (*dev->rx_pkt_burst)(rxq, rx_pkts, nb_pkts);$
WARNING: space prohibited between function name and open parenthesis '('
#93: FILE: lib/librte_ether/rte_ethdev.h:2466:
+ nb_rx =3D (*dev->rx_pkt_burst)(rxq, rx_pkts, nb_pkts);
ERROR: spaces required around that '=' (ctx:WxV)
#93: FILE: lib/librte_ether/rte_ethdev.h:2466:
+ nb_rx =3D (*dev->rx_pkt_burst)(rxq, rx_pkts, nb_pkts);
^
WARNING: please, no spaces at the start of a line
#94: FILE: lib/librte_ether/rte_ethdev.h:2467:
+ }$
WARNING: please, no spaces at the start of a line
#102: FILE: lib/librte_ether/rte_ethdev.h:2607:
+ void *txq;$
WARNING: please, no spaces at the start of a line
#110: FILE: lib/librte_ether/rte_ethdev.h:2624:
+ txq =3D dev->data->tx_queues[queue_id];$
ERROR: spaces required around that '=' (ctx:WxV)
#110: FILE: lib/librte_ether/rte_ethdev.h:2624:
+ txq =3D dev->data->tx_queues[queue_id];
^
WARNING: please, no spaces at the start of a line
#111: FILE: lib/librte_ether/rte_ethdev.h:2625:
+ rte_prefetch0(txq);$
WARNING: please, no spaces at the start of a line
#113: FILE: lib/librte_ether/rte_ethdev.h:2627:
+ return (*dev->tx_pkt_burst)(txq, tx_pkts, nb_pkts);$
total: 8 errors, 12 warnings, 38 lines checked
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [dpdk-dev] [PATCH v2] ethdev: Prefetch driver variable structure
2015-11-10 17:03 ` Stephen Hemminger
@ 2015-11-11 13:56 ` Polehn, Mike A
0 siblings, 0 replies; 6+ messages in thread
From: Polehn, Mike A @ 2015-11-11 13:56 UTC (permalink / raw)
To: Stephen Hemminger; +Cc: dev
It is probably the usual MS operation issues, I'll resubmit.
-----Original Message-----
From: Stephen Hemminger [mailto:stephen@networkplumber.org]
Sent: Tuesday, November 10, 2015 9:03 AM
To: Polehn, Mike A
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v2] ethdev: Prefetch driver variable structure
On Tue, 10 Nov 2015 14:17:41 +0000
"Polehn, Mike A" <mike.a.polehn@intel.com> wrote:
> Adds ethdev driver prefetch of variable structure to CPU cache 0 while
> calling into tx or rx device driver operation.
>
> RFC 2544 test of NIC task test measurement points show improvement of
> lower latency and/or better packet throughput indicating clock cycles
> saved.
>
> Signed-off-by: Mike A. Polehn <mike.a.polehn@intel.com>
Good idea, but lots of whitespace issues.
Please also check your mail client..
ERROR: patch seems to be corrupt (line wrapped?)
#80: FILE: lib/librte_ether/rte_ethdev.h:2457:
,
WARNING: please, no spaces at the start of a line
#84: FILE: lib/librte_ether/rte_ethdev.h:2460:
+ int16_t nb_rx;$
WARNING: please, no spaces at the start of a line
#89: FILE: lib/librte_ether/rte_ethdev.h:2462:
+ { /* limit scope of rxq variable */$
ERROR: code indent should use tabs where possible
#90: FILE: lib/librte_ether/rte_ethdev.h:2463:
+ /* rxq is going to be immediately used, prefetch it */$
ERROR: code indent should use tabs where possible
#91: FILE: lib/librte_ether/rte_ethdev.h:2464:
+ void *rxq =3D dev->data->rx_queues[queue_id];$
WARNING: please, no spaces at the start of a line
#91: FILE: lib/librte_ether/rte_ethdev.h:2464:
+ void *rxq =3D dev->data->rx_queues[queue_id];$
ERROR: spaces required around that '=' (ctx:WxV)
#91: FILE: lib/librte_ether/rte_ethdev.h:2464:
+ void *rxq =3D dev->data->rx_queues[queue_id];
^
ERROR: code indent should use tabs where possible
#92: FILE: lib/librte_ether/rte_ethdev.h:2465:
+ rte_prefetch0(rxq);$
WARNING: Missing a blank line after declarations
#92: FILE: lib/librte_ether/rte_ethdev.h:2465:
+ void *rxq =3D dev->data->rx_queues[queue_id];
+ rte_prefetch0(rxq);
WARNING: please, no spaces at the start of a line
#92: FILE: lib/librte_ether/rte_ethdev.h:2465:
+ rte_prefetch0(rxq);$
ERROR: code indent should use tabs where possible
#93: FILE: lib/librte_ether/rte_ethdev.h:2466:
+ nb_rx =3D (*dev->rx_pkt_burst)(rxq, rx_pkts, nb_pkts);$
WARNING: please, no spaces at the start of a line
#93: FILE: lib/librte_ether/rte_ethdev.h:2466:
+ nb_rx =3D (*dev->rx_pkt_burst)(rxq, rx_pkts, nb_pkts);$
WARNING: space prohibited between function name and open parenthesis '('
#93: FILE: lib/librte_ether/rte_ethdev.h:2466:
+ nb_rx =3D (*dev->rx_pkt_burst)(rxq, rx_pkts, nb_pkts);
ERROR: spaces required around that '=' (ctx:WxV)
#93: FILE: lib/librte_ether/rte_ethdev.h:2466:
+ nb_rx =3D (*dev->rx_pkt_burst)(rxq, rx_pkts, nb_pkts);
^
WARNING: please, no spaces at the start of a line
#94: FILE: lib/librte_ether/rte_ethdev.h:2467:
+ }$
WARNING: please, no spaces at the start of a line
#102: FILE: lib/librte_ether/rte_ethdev.h:2607:
+ void *txq;$
WARNING: please, no spaces at the start of a line
#110: FILE: lib/librte_ether/rte_ethdev.h:2624:
+ txq =3D dev->data->tx_queues[queue_id];$
ERROR: spaces required around that '=' (ctx:WxV)
#110: FILE: lib/librte_ether/rte_ethdev.h:2624:
+ txq =3D dev->data->tx_queues[queue_id];
^
WARNING: please, no spaces at the start of a line
#111: FILE: lib/librte_ether/rte_ethdev.h:2625:
+ rte_prefetch0(txq);$
WARNING: please, no spaces at the start of a line
#113: FILE: lib/librte_ether/rte_ethdev.h:2627:
+ return (*dev->tx_pkt_burst)(txq, tx_pkts, nb_pkts);$
total: 8 errors, 12 warnings, 38 lines checked
^ permalink raw reply [flat|nested] 6+ messages in thread
* [dpdk-dev] [PATCH v2] ethdev: Prefetch driver variable structure
@ 2015-11-11 13:59 Polehn, Mike A
2015-11-24 21:26 ` Thomas Monjalon
2018-12-19 21:14 ` Ferruh Yigit
0 siblings, 2 replies; 6+ messages in thread
From: Polehn, Mike A @ 2015-11-11 13:59 UTC (permalink / raw)
To: dev
Adds ethdev driver prefetch of variable structure to CPU cache 0
while calling into tx or rx device driver operation.
RFC 2544 test of NIC task test measurement points show improvement
of lower latency and/or better packet throughput indicating clock
cycles saved.
Signed-off-by: Mike A. Polehn <mike.a.polehn@intel.com>
---
lib/librte_ether/rte_ethdev.h | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
index 48a540d..f1c35de 100644
--- a/lib/librte_ether/rte_ethdev.h
+++ b/lib/librte_ether/rte_ethdev.h
@@ -2458,12 +2458,17 @@ rte_eth_rx_burst(uint8_t port_id, uint16_t queue_id,
struct rte_mbuf **rx_pkts, const uint16_t nb_pkts)
{
struct rte_eth_dev *dev;
+ int16_t nb_rx;
dev = &rte_eth_devices[port_id];
- int16_t nb_rx = (*dev->rx_pkt_burst)(dev->data->rx_queues[queue_id],
- rx_pkts, nb_pkts);
+ { /* limit scope of rxq variable */
+ /* rxq is going to be immediately used, prefetch it */
+ void *rxq = dev->data->rx_queues[queue_id];
+ rte_prefetch0(rxq);
+ nb_rx = (*dev->rx_pkt_burst)(rxq, rx_pkts, nb_pkts);
+ }
#ifdef RTE_ETHDEV_RXTX_CALLBACKS
struct rte_eth_rxtx_callback *cb = dev->post_rx_burst_cbs[queue_id];
@@ -2600,6 +2605,7 @@ rte_eth_tx_burst(uint8_t port_id, uint16_t queue_id,
struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
{
struct rte_eth_dev *dev;
+ void *txq;
dev = &rte_eth_devices[port_id];
@@ -2615,7 +2621,11 @@ rte_eth_tx_burst(uint8_t port_id, uint16_t queue_id,
}
#endif
- return (*dev->tx_pkt_burst)(dev->data->tx_queues[queue_id], tx_pkts, nb_pkts);
+ /* txq is going to be immediately used, prefetch it */
+ txq = dev->data->tx_queues[queue_id];
+ rte_prefetch0(txq);
+
+ return (*dev->tx_pkt_burst)(txq, tx_pkts, nb_pkts);
}
#endif
--
2.6.0
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [dpdk-dev] [PATCH v2] ethdev: Prefetch driver variable structure
2015-11-11 13:59 Polehn, Mike A
@ 2015-11-24 21:26 ` Thomas Monjalon
2018-12-19 21:14 ` Ferruh Yigit
1 sibling, 0 replies; 6+ messages in thread
From: Thomas Monjalon @ 2015-11-24 21:26 UTC (permalink / raw)
To: Polehn, Mike A, bruce.richardson; +Cc: dev
2015-11-11 13:59, Polehn, Mike A:
> Adds ethdev driver prefetch of variable structure to CPU cache 0
> while calling into tx or rx device driver operation.
>
> RFC 2544 test of NIC task test measurement points show improvement
> of lower latency and/or better packet throughput indicating clock
> cycles saved.
>
> Signed-off-by: Mike A. Polehn <mike.a.polehn@intel.com>
There are still some spacing issues with this patch.
Bruce, what is your opinion about this prefetch?
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [dpdk-dev] [PATCH v2] ethdev: Prefetch driver variable structure
2015-11-11 13:59 Polehn, Mike A
2015-11-24 21:26 ` Thomas Monjalon
@ 2018-12-19 21:14 ` Ferruh Yigit
1 sibling, 0 replies; 6+ messages in thread
From: Ferruh Yigit @ 2018-12-19 21:14 UTC (permalink / raw)
To: Polehn, Mike A; +Cc: dpdk-dev, Thomas Monjalon
On 11/11/2015 1:59 PM, mike.a.polehn at intel.com (Polehn, Mike A) wrote:
> Adds ethdev driver prefetch of variable structure to CPU cache 0
> while calling into tx or rx device driver operation.
>
> RFC 2544 test of NIC task test measurement points show improvement
> of lower latency and/or better packet throughput indicating clock
> cycles saved.
>
> Signed-off-by: Mike A. Polehn <mike.a.polehn at intel.com>
Hi Mike,
This patch is sitting on patchwork since 2015 without review, I am updating it
as rejected, if it is still relevant please let us know.
Sorry for any inconvenience caused.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-12-19 21:14 UTC | newest]
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2015-11-10 14:17 [dpdk-dev] [PATCH v2] ethdev: Prefetch driver variable structure Polehn, Mike A
2015-11-10 17:03 ` Stephen Hemminger
2015-11-11 13:56 ` Polehn, Mike A
2015-11-11 13:59 Polehn, Mike A
2015-11-24 21:26 ` Thomas Monjalon
2018-12-19 21:14 ` Ferruh Yigit
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