* [PATCH net-next v2] virtio_net: add support for Byte Queue Limits
@ 2024-06-12 17:08 Jiri Pirko
2024-06-12 22:30 ` Michael S. Tsirkin
` (3 more replies)
0 siblings, 4 replies; 11+ messages in thread
From: Jiri Pirko @ 2024-06-12 17:08 UTC (permalink / raw)
To: netdev
Cc: davem, edumazet, kuba, pabeni, mst, jasowang, xuanzhuo,
virtualization, ast, daniel, hawk, john.fastabend, dave.taht,
kerneljasonxing, hengqi
From: Jiri Pirko <jiri@nvidia.com>
Add support for Byte Queue Limits (BQL).
Tested on qemu emulated virtio_net device with 1, 2 and 4 queues.
Tested with fq_codel and pfifo_fast. Super netperf with 50 threads is
running in background. Netperf TCP_RR results:
NOBQL FQC 1q: 159.56 159.33 158.50 154.31 agv: 157.925
NOBQL FQC 2q: 184.64 184.96 174.73 174.15 agv: 179.62
NOBQL FQC 4q: 994.46 441.96 416.50 499.56 agv: 588.12
NOBQL PFF 1q: 148.68 148.92 145.95 149.48 agv: 148.2575
NOBQL PFF 2q: 171.86 171.20 170.42 169.42 agv: 170.725
NOBQL PFF 4q: 1505.23 1137.23 2488.70 3507.99 agv: 2159.7875
BQL FQC 1q: 1332.80 1297.97 1351.41 1147.57 agv: 1282.4375
BQL FQC 2q: 768.30 817.72 864.43 974.40 agv: 856.2125
BQL FQC 4q: 945.66 942.68 878.51 822.82 agv: 897.4175
BQL PFF 1q: 149.69 151.49 149.40 147.47 agv: 149.5125
BQL PFF 2q: 2059.32 798.74 1844.12 381.80 agv: 1270.995
BQL PFF 4q: 1871.98 4420.02 4916.59 13268.16 agv: 6119.1875
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
v1->v2:
- moved netdev_tx_completed_queue() call into __free_old_xmit(),
propagate use_napi flag to __free_old_xmit() and only call
netdev_tx_completed_queue() in case it is true
- added forgotten call to netdev_tx_reset_queue()
- fixed stats for xdp packets
- fixed bql accounting when __free_old_xmit() is called from xdp path
- handle the !use_napi case in start_xmit() kick section
---
drivers/net/virtio_net.c | 50 +++++++++++++++++++++++++---------------
1 file changed, 32 insertions(+), 18 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 61a57d134544..5863c663ccab 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -84,7 +84,9 @@ struct virtnet_stat_desc {
struct virtnet_sq_free_stats {
u64 packets;
+ u64 xdp_packets;
u64 bytes;
+ u64 xdp_bytes;
};
struct virtnet_sq_stats {
@@ -506,29 +508,33 @@ static struct xdp_frame *ptr_to_xdp(void *ptr)
return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
}
-static void __free_old_xmit(struct send_queue *sq, bool in_napi,
+static void __free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
+ bool in_napi, bool use_napi,
struct virtnet_sq_free_stats *stats)
{
unsigned int len;
void *ptr;
while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
- ++stats->packets;
-
if (!is_xdp_frame(ptr)) {
struct sk_buff *skb = ptr;
pr_debug("Sent skb %p\n", skb);
+ stats->packets++;
stats->bytes += skb->len;
napi_consume_skb(skb, in_napi);
} else {
struct xdp_frame *frame = ptr_to_xdp(ptr);
- stats->bytes += xdp_get_frame_len(frame);
+ stats->xdp_packets++;
+ stats->xdp_bytes += xdp_get_frame_len(frame);
xdp_return_frame(frame);
}
}
+ if (use_napi)
+ netdev_tx_completed_queue(txq, stats->packets, stats->bytes);
+
}
/* Converting between virtqueue no. and kernel tx/rx queue no.
@@ -955,21 +961,22 @@ static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf)
virtnet_rq_free_buf(vi, rq, buf);
}
-static void free_old_xmit(struct send_queue *sq, bool in_napi)
+static void free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
+ bool in_napi, bool use_napi)
{
struct virtnet_sq_free_stats stats = {0};
- __free_old_xmit(sq, in_napi, &stats);
+ __free_old_xmit(sq, txq, in_napi, use_napi, &stats);
/* Avoid overhead when no packets have been processed
* happens when called speculatively from start_xmit.
*/
- if (!stats.packets)
+ if (!stats.packets && !stats.xdp_packets)
return;
u64_stats_update_begin(&sq->stats.syncp);
- u64_stats_add(&sq->stats.bytes, stats.bytes);
- u64_stats_add(&sq->stats.packets, stats.packets);
+ u64_stats_add(&sq->stats.bytes, stats.bytes + stats.xdp_bytes);
+ u64_stats_add(&sq->stats.packets, stats.packets + stats.xdp_packets);
u64_stats_update_end(&sq->stats.syncp);
}
@@ -1003,7 +1010,9 @@ static void check_sq_full_and_disable(struct virtnet_info *vi,
* early means 16 slots are typically wasted.
*/
if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
- netif_stop_subqueue(dev, qnum);
+ struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
+
+ netif_tx_stop_queue(txq);
u64_stats_update_begin(&sq->stats.syncp);
u64_stats_inc(&sq->stats.stop);
u64_stats_update_end(&sq->stats.syncp);
@@ -1012,7 +1021,7 @@ static void check_sq_full_and_disable(struct virtnet_info *vi,
virtqueue_napi_schedule(&sq->napi, sq->vq);
} else if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
/* More just got used, free them then recheck. */
- free_old_xmit(sq, false);
+ free_old_xmit(sq, txq, false, use_napi);
if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
netif_start_subqueue(dev, qnum);
u64_stats_update_begin(&sq->stats.syncp);
@@ -1138,7 +1147,8 @@ static int virtnet_xdp_xmit(struct net_device *dev,
}
/* Free up any pending old buffers before queueing new ones. */
- __free_old_xmit(sq, false, &stats);
+ __free_old_xmit(sq, netdev_get_tx_queue(dev, sq - vi->sq),
+ false, sq->napi.weight, &stats);
for (i = 0; i < n; i++) {
struct xdp_frame *xdpf = frames[i];
@@ -2313,7 +2323,7 @@ static void virtnet_poll_cleantx(struct receive_queue *rq)
do {
virtqueue_disable_cb(sq->vq);
- free_old_xmit(sq, true);
+ free_old_xmit(sq, txq, true, true);
} while (unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) {
@@ -2412,6 +2422,7 @@ static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
goto err_xdp_reg_mem_model;
virtnet_napi_enable(vi->rq[qp_index].vq, &vi->rq[qp_index].napi);
+ netdev_tx_reset_queue(netdev_get_tx_queue(vi->dev, qp_index));
virtnet_napi_tx_enable(vi, vi->sq[qp_index].vq, &vi->sq[qp_index].napi);
return 0;
@@ -2471,7 +2482,7 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget)
txq = netdev_get_tx_queue(vi->dev, index);
__netif_tx_lock(txq, raw_smp_processor_id());
virtqueue_disable_cb(sq->vq);
- free_old_xmit(sq, true);
+ free_old_xmit(sq, txq, true, true);
if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) {
if (netif_tx_queue_stopped(txq)) {
@@ -2559,17 +2570,18 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
struct send_queue *sq = &vi->sq[qnum];
int err;
struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
- bool kick = !netdev_xmit_more();
+ bool xmit_more = netdev_xmit_more();
bool use_napi = sq->napi.weight;
+ bool kick;
/* Free up any pending old buffers before queueing new ones. */
do {
if (use_napi)
virtqueue_disable_cb(sq->vq);
- free_old_xmit(sq, false);
+ free_old_xmit(sq, txq, false, use_napi);
- } while (use_napi && kick &&
+ } while (use_napi && !xmit_more &&
unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
/* timestamp packet in software */
@@ -2598,7 +2610,9 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
check_sq_full_and_disable(vi, dev, sq);
- if (kick || netif_xmit_stopped(txq)) {
+ kick = use_napi ? __netdev_tx_sent_queue(txq, skb->len, xmit_more) :
+ !xmit_more && netif_xmit_stopped(txq);
+ if (kick) {
if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
u64_stats_update_begin(&sq->stats.syncp);
u64_stats_inc(&sq->stats.kicks);
--
2.45.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH net-next v2] virtio_net: add support for Byte Queue Limits
2024-06-12 17:08 [PATCH net-next v2] virtio_net: add support for Byte Queue Limits Jiri Pirko
@ 2024-06-12 22:30 ` Michael S. Tsirkin
2024-06-14 9:54 ` Jason Xing
` (2 subsequent siblings)
3 siblings, 0 replies; 11+ messages in thread
From: Michael S. Tsirkin @ 2024-06-12 22:30 UTC (permalink / raw)
To: Jiri Pirko
Cc: netdev, davem, edumazet, kuba, pabeni, jasowang, xuanzhuo,
virtualization, ast, daniel, hawk, john.fastabend, dave.taht,
kerneljasonxing, hengqi
On Wed, Jun 12, 2024 at 07:08:51PM +0200, Jiri Pirko wrote:
> From: Jiri Pirko <jiri@nvidia.com>
>
> Add support for Byte Queue Limits (BQL).
>
> Tested on qemu emulated virtio_net device with 1, 2 and 4 queues.
> Tested with fq_codel and pfifo_fast. Super netperf with 50 threads is
> running in background. Netperf TCP_RR results:
>
> NOBQL FQC 1q: 159.56 159.33 158.50 154.31 agv: 157.925
> NOBQL FQC 2q: 184.64 184.96 174.73 174.15 agv: 179.62
> NOBQL FQC 4q: 994.46 441.96 416.50 499.56 agv: 588.12
> NOBQL PFF 1q: 148.68 148.92 145.95 149.48 agv: 148.2575
> NOBQL PFF 2q: 171.86 171.20 170.42 169.42 agv: 170.725
> NOBQL PFF 4q: 1505.23 1137.23 2488.70 3507.99 agv: 2159.7875
> BQL FQC 1q: 1332.80 1297.97 1351.41 1147.57 agv: 1282.4375
> BQL FQC 2q: 768.30 817.72 864.43 974.40 agv: 856.2125
> BQL FQC 4q: 945.66 942.68 878.51 822.82 agv: 897.4175
> BQL PFF 1q: 149.69 151.49 149.40 147.47 agv: 149.5125
> BQL PFF 2q: 2059.32 798.74 1844.12 381.80 agv: 1270.995
> BQL PFF 4q: 1871.98 4420.02 4916.59 13268.16 agv: 6119.1875
>
> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
I see you now support both napi and non-napi. Thanks a lot Jiri!
Just coming out of a national holiday here, as usual with a backlog - pls allow
until Monday to review. Thanks!
> ---
> v1->v2:
> - moved netdev_tx_completed_queue() call into __free_old_xmit(),
> propagate use_napi flag to __free_old_xmit() and only call
> netdev_tx_completed_queue() in case it is true
> - added forgotten call to netdev_tx_reset_queue()
> - fixed stats for xdp packets
> - fixed bql accounting when __free_old_xmit() is called from xdp path
> - handle the !use_napi case in start_xmit() kick section
> ---
> drivers/net/virtio_net.c | 50 +++++++++++++++++++++++++---------------
> 1 file changed, 32 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 61a57d134544..5863c663ccab 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -84,7 +84,9 @@ struct virtnet_stat_desc {
>
> struct virtnet_sq_free_stats {
> u64 packets;
> + u64 xdp_packets;
> u64 bytes;
> + u64 xdp_bytes;
> };
>
> struct virtnet_sq_stats {
> @@ -506,29 +508,33 @@ static struct xdp_frame *ptr_to_xdp(void *ptr)
> return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
> }
>
> -static void __free_old_xmit(struct send_queue *sq, bool in_napi,
> +static void __free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
> + bool in_napi, bool use_napi,
> struct virtnet_sq_free_stats *stats)
> {
> unsigned int len;
> void *ptr;
>
> while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
> - ++stats->packets;
> -
> if (!is_xdp_frame(ptr)) {
> struct sk_buff *skb = ptr;
>
> pr_debug("Sent skb %p\n", skb);
>
> + stats->packets++;
> stats->bytes += skb->len;
> napi_consume_skb(skb, in_napi);
> } else {
> struct xdp_frame *frame = ptr_to_xdp(ptr);
>
> - stats->bytes += xdp_get_frame_len(frame);
> + stats->xdp_packets++;
> + stats->xdp_bytes += xdp_get_frame_len(frame);
> xdp_return_frame(frame);
> }
> }
> + if (use_napi)
> + netdev_tx_completed_queue(txq, stats->packets, stats->bytes);
> +
> }
>
> /* Converting between virtqueue no. and kernel tx/rx queue no.
> @@ -955,21 +961,22 @@ static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf)
> virtnet_rq_free_buf(vi, rq, buf);
> }
>
> -static void free_old_xmit(struct send_queue *sq, bool in_napi)
> +static void free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
> + bool in_napi, bool use_napi)
> {
> struct virtnet_sq_free_stats stats = {0};
>
> - __free_old_xmit(sq, in_napi, &stats);
> + __free_old_xmit(sq, txq, in_napi, use_napi, &stats);
>
> /* Avoid overhead when no packets have been processed
> * happens when called speculatively from start_xmit.
> */
> - if (!stats.packets)
> + if (!stats.packets && !stats.xdp_packets)
> return;
>
> u64_stats_update_begin(&sq->stats.syncp);
> - u64_stats_add(&sq->stats.bytes, stats.bytes);
> - u64_stats_add(&sq->stats.packets, stats.packets);
> + u64_stats_add(&sq->stats.bytes, stats.bytes + stats.xdp_bytes);
> + u64_stats_add(&sq->stats.packets, stats.packets + stats.xdp_packets);
> u64_stats_update_end(&sq->stats.syncp);
> }
>
> @@ -1003,7 +1010,9 @@ static void check_sq_full_and_disable(struct virtnet_info *vi,
> * early means 16 slots are typically wasted.
> */
> if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
> - netif_stop_subqueue(dev, qnum);
> + struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
> +
> + netif_tx_stop_queue(txq);
> u64_stats_update_begin(&sq->stats.syncp);
> u64_stats_inc(&sq->stats.stop);
> u64_stats_update_end(&sq->stats.syncp);
> @@ -1012,7 +1021,7 @@ static void check_sq_full_and_disable(struct virtnet_info *vi,
> virtqueue_napi_schedule(&sq->napi, sq->vq);
> } else if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
> /* More just got used, free them then recheck. */
> - free_old_xmit(sq, false);
> + free_old_xmit(sq, txq, false, use_napi);
> if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
> netif_start_subqueue(dev, qnum);
> u64_stats_update_begin(&sq->stats.syncp);
> @@ -1138,7 +1147,8 @@ static int virtnet_xdp_xmit(struct net_device *dev,
> }
>
> /* Free up any pending old buffers before queueing new ones. */
> - __free_old_xmit(sq, false, &stats);
> + __free_old_xmit(sq, netdev_get_tx_queue(dev, sq - vi->sq),
> + false, sq->napi.weight, &stats);
>
> for (i = 0; i < n; i++) {
> struct xdp_frame *xdpf = frames[i];
> @@ -2313,7 +2323,7 @@ static void virtnet_poll_cleantx(struct receive_queue *rq)
>
> do {
> virtqueue_disable_cb(sq->vq);
> - free_old_xmit(sq, true);
> + free_old_xmit(sq, txq, true, true);
> } while (unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
>
> if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) {
> @@ -2412,6 +2422,7 @@ static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
> goto err_xdp_reg_mem_model;
>
> virtnet_napi_enable(vi->rq[qp_index].vq, &vi->rq[qp_index].napi);
> + netdev_tx_reset_queue(netdev_get_tx_queue(vi->dev, qp_index));
> virtnet_napi_tx_enable(vi, vi->sq[qp_index].vq, &vi->sq[qp_index].napi);
>
> return 0;
> @@ -2471,7 +2482,7 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget)
> txq = netdev_get_tx_queue(vi->dev, index);
> __netif_tx_lock(txq, raw_smp_processor_id());
> virtqueue_disable_cb(sq->vq);
> - free_old_xmit(sq, true);
> + free_old_xmit(sq, txq, true, true);
>
> if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) {
> if (netif_tx_queue_stopped(txq)) {
> @@ -2559,17 +2570,18 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
> struct send_queue *sq = &vi->sq[qnum];
> int err;
> struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
> - bool kick = !netdev_xmit_more();
> + bool xmit_more = netdev_xmit_more();
> bool use_napi = sq->napi.weight;
> + bool kick;
>
> /* Free up any pending old buffers before queueing new ones. */
> do {
> if (use_napi)
> virtqueue_disable_cb(sq->vq);
>
> - free_old_xmit(sq, false);
> + free_old_xmit(sq, txq, false, use_napi);
>
> - } while (use_napi && kick &&
> + } while (use_napi && !xmit_more &&
> unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
>
> /* timestamp packet in software */
> @@ -2598,7 +2610,9 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
>
> check_sq_full_and_disable(vi, dev, sq);
>
> - if (kick || netif_xmit_stopped(txq)) {
> + kick = use_napi ? __netdev_tx_sent_queue(txq, skb->len, xmit_more) :
> + !xmit_more && netif_xmit_stopped(txq);
> + if (kick) {
> if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
> u64_stats_update_begin(&sq->stats.syncp);
> u64_stats_inc(&sq->stats.kicks);
> --
> 2.45.1
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH net-next v2] virtio_net: add support for Byte Queue Limits
2024-06-12 17:08 [PATCH net-next v2] virtio_net: add support for Byte Queue Limits Jiri Pirko
2024-06-12 22:30 ` Michael S. Tsirkin
@ 2024-06-14 9:54 ` Jason Xing
2024-06-17 9:15 ` Jiri Pirko
2024-06-17 2:34 ` Jason Wang
2024-06-17 16:14 ` Michael S. Tsirkin
3 siblings, 1 reply; 11+ messages in thread
From: Jason Xing @ 2024-06-14 9:54 UTC (permalink / raw)
To: Jiri Pirko
Cc: netdev, davem, edumazet, kuba, pabeni, mst, jasowang, xuanzhuo,
virtualization, ast, daniel, hawk, john.fastabend, dave.taht,
hengqi
Hello Jiri,
On Thu, Jun 13, 2024 at 1:08 AM Jiri Pirko <jiri@resnulli.us> wrote:
>
> From: Jiri Pirko <jiri@nvidia.com>
>
> Add support for Byte Queue Limits (BQL).
>
> Tested on qemu emulated virtio_net device with 1, 2 and 4 queues.
> Tested with fq_codel and pfifo_fast. Super netperf with 50 threads is
> running in background. Netperf TCP_RR results:
>
> NOBQL FQC 1q: 159.56 159.33 158.50 154.31 agv: 157.925
> NOBQL FQC 2q: 184.64 184.96 174.73 174.15 agv: 179.62
> NOBQL FQC 4q: 994.46 441.96 416.50 499.56 agv: 588.12
> NOBQL PFF 1q: 148.68 148.92 145.95 149.48 agv: 148.2575
> NOBQL PFF 2q: 171.86 171.20 170.42 169.42 agv: 170.725
> NOBQL PFF 4q: 1505.23 1137.23 2488.70 3507.99 agv: 2159.7875
> BQL FQC 1q: 1332.80 1297.97 1351.41 1147.57 agv: 1282.4375
> BQL FQC 2q: 768.30 817.72 864.43 974.40 agv: 856.2125
> BQL FQC 4q: 945.66 942.68 878.51 822.82 agv: 897.4175
> BQL PFF 1q: 149.69 151.49 149.40 147.47 agv: 149.5125
> BQL PFF 2q: 2059.32 798.74 1844.12 381.80 agv: 1270.995
> BQL PFF 4q: 1871.98 4420.02 4916.59 13268.16 agv: 6119.1875
I cannot get such a huge improvement when I was doing multiple tests
between two VMs. I'm pretty sure the BQL feature is working, but the
numbers look the same with/without BQL.
VM 1 (client):
16 cpus, x86_64, 4 queues, the latest net-next kernel with/without
this patch, pfifo_fast, napi_tx=true, napi_weight=128
VM 2 (server):
16 cpus, aarch64, 4 queues, the latest net-next kernel without this
patch, pfifo_fast
What the 'ping' command shows to me between two VMs is : rtt
min/avg/max/mdev = 0.233/0.257/0.300/0.024 ms
I started 50 netperfs to communicate the other side with the following command:
#!/bin/bash
for i in $(seq 5000 5050);
do
netperf -p $i -H [ip addr] -l 60 -t TCP_RR -- -r 64,64 > /dev/null 2>&1 &
done
The results are around 30423.62 txkB/s. If I remove '-r 64 64', they
are still the same/similar.
Am I missing something?
Thanks,
Jason
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH net-next v2] virtio_net: add support for Byte Queue Limits
2024-06-12 17:08 [PATCH net-next v2] virtio_net: add support for Byte Queue Limits Jiri Pirko
2024-06-12 22:30 ` Michael S. Tsirkin
2024-06-14 9:54 ` Jason Xing
@ 2024-06-17 2:34 ` Jason Wang
2024-06-17 9:18 ` Jiri Pirko
2024-06-17 16:14 ` Michael S. Tsirkin
3 siblings, 1 reply; 11+ messages in thread
From: Jason Wang @ 2024-06-17 2:34 UTC (permalink / raw)
To: Jiri Pirko
Cc: netdev, davem, edumazet, kuba, pabeni, mst, xuanzhuo,
virtualization, ast, daniel, hawk, john.fastabend, dave.taht,
kerneljasonxing, hengqi
On Thu, Jun 13, 2024 at 1:09 AM Jiri Pirko <jiri@resnulli.us> wrote:
>
> From: Jiri Pirko <jiri@nvidia.com>
>
> Add support for Byte Queue Limits (BQL).
>
> Tested on qemu emulated virtio_net device with 1, 2 and 4 queues.
> Tested with fq_codel and pfifo_fast. Super netperf with 50 threads is
> running in background. Netperf TCP_RR results:
>
> NOBQL FQC 1q: 159.56 159.33 158.50 154.31 agv: 157.925
> NOBQL FQC 2q: 184.64 184.96 174.73 174.15 agv: 179.62
> NOBQL FQC 4q: 994.46 441.96 416.50 499.56 agv: 588.12
> NOBQL PFF 1q: 148.68 148.92 145.95 149.48 agv: 148.2575
> NOBQL PFF 2q: 171.86 171.20 170.42 169.42 agv: 170.725
> NOBQL PFF 4q: 1505.23 1137.23 2488.70 3507.99 agv: 2159.7875
> BQL FQC 1q: 1332.80 1297.97 1351.41 1147.57 agv: 1282.4375
> BQL FQC 2q: 768.30 817.72 864.43 974.40 agv: 856.2125
> BQL FQC 4q: 945.66 942.68 878.51 822.82 agv: 897.4175
> BQL PFF 1q: 149.69 151.49 149.40 147.47 agv: 149.5125
> BQL PFF 2q: 2059.32 798.74 1844.12 381.80 agv: 1270.995
> BQL PFF 4q: 1871.98 4420.02 4916.59 13268.16 agv: 6119.1875
>
> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
> ---
> v1->v2:
> - moved netdev_tx_completed_queue() call into __free_old_xmit(),
> propagate use_napi flag to __free_old_xmit() and only call
> netdev_tx_completed_queue() in case it is true
> - added forgotten call to netdev_tx_reset_queue()
> - fixed stats for xdp packets
> - fixed bql accounting when __free_old_xmit() is called from xdp path
> - handle the !use_napi case in start_xmit() kick section
> ---
> drivers/net/virtio_net.c | 50 +++++++++++++++++++++++++---------------
> 1 file changed, 32 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 61a57d134544..5863c663ccab 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -84,7 +84,9 @@ struct virtnet_stat_desc {
>
> struct virtnet_sq_free_stats {
> u64 packets;
> + u64 xdp_packets;
> u64 bytes;
> + u64 xdp_bytes;
> };
>
> struct virtnet_sq_stats {
> @@ -506,29 +508,33 @@ static struct xdp_frame *ptr_to_xdp(void *ptr)
> return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
> }
>
> -static void __free_old_xmit(struct send_queue *sq, bool in_napi,
> +static void __free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
> + bool in_napi, bool use_napi,
> struct virtnet_sq_free_stats *stats)
> {
> unsigned int len;
> void *ptr;
>
> while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
> - ++stats->packets;
> -
> if (!is_xdp_frame(ptr)) {
> struct sk_buff *skb = ptr;
>
> pr_debug("Sent skb %p\n", skb);
>
> + stats->packets++;
> stats->bytes += skb->len;
> napi_consume_skb(skb, in_napi);
> } else {
> struct xdp_frame *frame = ptr_to_xdp(ptr);
>
> - stats->bytes += xdp_get_frame_len(frame);
> + stats->xdp_packets++;
> + stats->xdp_bytes += xdp_get_frame_len(frame);
> xdp_return_frame(frame);
> }
> }
> + if (use_napi)
> + netdev_tx_completed_queue(txq, stats->packets, stats->bytes);
> +
> }
I wonder if this works correctly, for example NAPI could be enabled
after queued but before sent. So __netdev_tx_sent_queue() is not
called before.
Thanks
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH net-next v2] virtio_net: add support for Byte Queue Limits
2024-06-14 9:54 ` Jason Xing
@ 2024-06-17 9:15 ` Jiri Pirko
2024-06-17 15:47 ` Jason Xing
0 siblings, 1 reply; 11+ messages in thread
From: Jiri Pirko @ 2024-06-17 9:15 UTC (permalink / raw)
To: Jason Xing
Cc: netdev, davem, edumazet, kuba, pabeni, mst, jasowang, xuanzhuo,
virtualization, ast, daniel, hawk, john.fastabend, dave.taht,
hengqi
Fri, Jun 14, 2024 at 11:54:04AM CEST, kerneljasonxing@gmail.com wrote:
>Hello Jiri,
>
>On Thu, Jun 13, 2024 at 1:08 AM Jiri Pirko <jiri@resnulli.us> wrote:
>>
>> From: Jiri Pirko <jiri@nvidia.com>
>>
>> Add support for Byte Queue Limits (BQL).
>>
>> Tested on qemu emulated virtio_net device with 1, 2 and 4 queues.
>> Tested with fq_codel and pfifo_fast. Super netperf with 50 threads is
>> running in background. Netperf TCP_RR results:
>>
>> NOBQL FQC 1q: 159.56 159.33 158.50 154.31 agv: 157.925
>> NOBQL FQC 2q: 184.64 184.96 174.73 174.15 agv: 179.62
>> NOBQL FQC 4q: 994.46 441.96 416.50 499.56 agv: 588.12
>> NOBQL PFF 1q: 148.68 148.92 145.95 149.48 agv: 148.2575
>> NOBQL PFF 2q: 171.86 171.20 170.42 169.42 agv: 170.725
>> NOBQL PFF 4q: 1505.23 1137.23 2488.70 3507.99 agv: 2159.7875
>> BQL FQC 1q: 1332.80 1297.97 1351.41 1147.57 agv: 1282.4375
>> BQL FQC 2q: 768.30 817.72 864.43 974.40 agv: 856.2125
>> BQL FQC 4q: 945.66 942.68 878.51 822.82 agv: 897.4175
>> BQL PFF 1q: 149.69 151.49 149.40 147.47 agv: 149.5125
>> BQL PFF 2q: 2059.32 798.74 1844.12 381.80 agv: 1270.995
>> BQL PFF 4q: 1871.98 4420.02 4916.59 13268.16 agv: 6119.1875
>
>I cannot get such a huge improvement when I was doing multiple tests
>between two VMs. I'm pretty sure the BQL feature is working, but the
>numbers look the same with/without BQL.
>
>VM 1 (client):
>16 cpus, x86_64, 4 queues, the latest net-next kernel with/without
>this patch, pfifo_fast, napi_tx=true, napi_weight=128
>
>VM 2 (server):
>16 cpus, aarch64, 4 queues, the latest net-next kernel without this
>patch, pfifo_fast
>
>What the 'ping' command shows to me between two VMs is : rtt
>min/avg/max/mdev = 0.233/0.257/0.300/0.024 ms
>
>I started 50 netperfs to communicate the other side with the following command:
>#!/bin/bash
>
>for i in $(seq 5000 5050);
>do
>netperf -p $i -H [ip addr] -l 60 -t TCP_RR -- -r 64,64 > /dev/null 2>&1 &
>done
>
>The results are around 30423.62 txkB/s. If I remove '-r 64 64', they
>are still the same/similar.
You have to stress the line by parallel TCP_STREAM instances (50 in my
case). For consistent results, use -p portnum,locport to specify the
local port.
Then run TCP_RR, also use -p portnum,locport to specify the local port.
Also, double check the CONFIG_BQL=y is set.
>
>Am I missing something?
>
>Thanks,
>Jason
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH net-next v2] virtio_net: add support for Byte Queue Limits
2024-06-17 2:34 ` Jason Wang
@ 2024-06-17 9:18 ` Jiri Pirko
2024-06-18 0:53 ` Jason Wang
0 siblings, 1 reply; 11+ messages in thread
From: Jiri Pirko @ 2024-06-17 9:18 UTC (permalink / raw)
To: Jason Wang
Cc: netdev, davem, edumazet, kuba, pabeni, mst, xuanzhuo,
virtualization, ast, daniel, hawk, john.fastabend, dave.taht,
kerneljasonxing, hengqi
Mon, Jun 17, 2024 at 04:34:26AM CEST, jasowang@redhat.com wrote:
>On Thu, Jun 13, 2024 at 1:09 AM Jiri Pirko <jiri@resnulli.us> wrote:
>>
>> From: Jiri Pirko <jiri@nvidia.com>
>>
>> Add support for Byte Queue Limits (BQL).
>>
>> Tested on qemu emulated virtio_net device with 1, 2 and 4 queues.
>> Tested with fq_codel and pfifo_fast. Super netperf with 50 threads is
>> running in background. Netperf TCP_RR results:
>>
>> NOBQL FQC 1q: 159.56 159.33 158.50 154.31 agv: 157.925
>> NOBQL FQC 2q: 184.64 184.96 174.73 174.15 agv: 179.62
>> NOBQL FQC 4q: 994.46 441.96 416.50 499.56 agv: 588.12
>> NOBQL PFF 1q: 148.68 148.92 145.95 149.48 agv: 148.2575
>> NOBQL PFF 2q: 171.86 171.20 170.42 169.42 agv: 170.725
>> NOBQL PFF 4q: 1505.23 1137.23 2488.70 3507.99 agv: 2159.7875
>> BQL FQC 1q: 1332.80 1297.97 1351.41 1147.57 agv: 1282.4375
>> BQL FQC 2q: 768.30 817.72 864.43 974.40 agv: 856.2125
>> BQL FQC 4q: 945.66 942.68 878.51 822.82 agv: 897.4175
>> BQL PFF 1q: 149.69 151.49 149.40 147.47 agv: 149.5125
>> BQL PFF 2q: 2059.32 798.74 1844.12 381.80 agv: 1270.995
>> BQL PFF 4q: 1871.98 4420.02 4916.59 13268.16 agv: 6119.1875
>>
>> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
>> ---
>> v1->v2:
>> - moved netdev_tx_completed_queue() call into __free_old_xmit(),
>> propagate use_napi flag to __free_old_xmit() and only call
>> netdev_tx_completed_queue() in case it is true
>> - added forgotten call to netdev_tx_reset_queue()
>> - fixed stats for xdp packets
>> - fixed bql accounting when __free_old_xmit() is called from xdp path
>> - handle the !use_napi case in start_xmit() kick section
>> ---
>> drivers/net/virtio_net.c | 50 +++++++++++++++++++++++++---------------
>> 1 file changed, 32 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> index 61a57d134544..5863c663ccab 100644
>> --- a/drivers/net/virtio_net.c
>> +++ b/drivers/net/virtio_net.c
>> @@ -84,7 +84,9 @@ struct virtnet_stat_desc {
>>
>> struct virtnet_sq_free_stats {
>> u64 packets;
>> + u64 xdp_packets;
>> u64 bytes;
>> + u64 xdp_bytes;
>> };
>>
>> struct virtnet_sq_stats {
>> @@ -506,29 +508,33 @@ static struct xdp_frame *ptr_to_xdp(void *ptr)
>> return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
>> }
>>
>> -static void __free_old_xmit(struct send_queue *sq, bool in_napi,
>> +static void __free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
>> + bool in_napi, bool use_napi,
>> struct virtnet_sq_free_stats *stats)
>> {
>> unsigned int len;
>> void *ptr;
>>
>> while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
>> - ++stats->packets;
>> -
>> if (!is_xdp_frame(ptr)) {
>> struct sk_buff *skb = ptr;
>>
>> pr_debug("Sent skb %p\n", skb);
>>
>> + stats->packets++;
>> stats->bytes += skb->len;
>> napi_consume_skb(skb, in_napi);
>> } else {
>> struct xdp_frame *frame = ptr_to_xdp(ptr);
>>
>> - stats->bytes += xdp_get_frame_len(frame);
>> + stats->xdp_packets++;
>> + stats->xdp_bytes += xdp_get_frame_len(frame);
>> xdp_return_frame(frame);
>> }
>> }
>> + if (use_napi)
>> + netdev_tx_completed_queue(txq, stats->packets, stats->bytes);
>> +
>> }
>
>I wonder if this works correctly, for example NAPI could be enabled
>after queued but before sent. So __netdev_tx_sent_queue() is not
>called before.
How is that possible? Napi weight can't change when link is up. Or am I
missing something?
>
>Thanks
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH net-next v2] virtio_net: add support for Byte Queue Limits
2024-06-17 9:15 ` Jiri Pirko
@ 2024-06-17 15:47 ` Jason Xing
0 siblings, 0 replies; 11+ messages in thread
From: Jason Xing @ 2024-06-17 15:47 UTC (permalink / raw)
To: Jiri Pirko
Cc: netdev, davem, edumazet, kuba, pabeni, mst, jasowang, xuanzhuo,
virtualization, ast, daniel, hawk, john.fastabend, dave.taht,
hengqi
On Mon, Jun 17, 2024 at 5:15 PM Jiri Pirko <jiri@resnulli.us> wrote:
>
> Fri, Jun 14, 2024 at 11:54:04AM CEST, kerneljasonxing@gmail.com wrote:
> >Hello Jiri,
> >
> >On Thu, Jun 13, 2024 at 1:08 AM Jiri Pirko <jiri@resnulli.us> wrote:
> >>
> >> From: Jiri Pirko <jiri@nvidia.com>
> >>
> >> Add support for Byte Queue Limits (BQL).
> >>
> >> Tested on qemu emulated virtio_net device with 1, 2 and 4 queues.
> >> Tested with fq_codel and pfifo_fast. Super netperf with 50 threads is
> >> running in background. Netperf TCP_RR results:
> >>
> >> NOBQL FQC 1q: 159.56 159.33 158.50 154.31 agv: 157.925
> >> NOBQL FQC 2q: 184.64 184.96 174.73 174.15 agv: 179.62
> >> NOBQL FQC 4q: 994.46 441.96 416.50 499.56 agv: 588.12
> >> NOBQL PFF 1q: 148.68 148.92 145.95 149.48 agv: 148.2575
> >> NOBQL PFF 2q: 171.86 171.20 170.42 169.42 agv: 170.725
> >> NOBQL PFF 4q: 1505.23 1137.23 2488.70 3507.99 agv: 2159.7875
> >> BQL FQC 1q: 1332.80 1297.97 1351.41 1147.57 agv: 1282.4375
> >> BQL FQC 2q: 768.30 817.72 864.43 974.40 agv: 856.2125
> >> BQL FQC 4q: 945.66 942.68 878.51 822.82 agv: 897.4175
> >> BQL PFF 1q: 149.69 151.49 149.40 147.47 agv: 149.5125
> >> BQL PFF 2q: 2059.32 798.74 1844.12 381.80 agv: 1270.995
> >> BQL PFF 4q: 1871.98 4420.02 4916.59 13268.16 agv: 6119.1875
> >
> >I cannot get such a huge improvement when I was doing multiple tests
> >between two VMs. I'm pretty sure the BQL feature is working, but the
> >numbers look the same with/without BQL.
> >
> >VM 1 (client):
> >16 cpus, x86_64, 4 queues, the latest net-next kernel with/without
> >this patch, pfifo_fast, napi_tx=true, napi_weight=128
> >
> >VM 2 (server):
> >16 cpus, aarch64, 4 queues, the latest net-next kernel without this
> >patch, pfifo_fast
> >
> >What the 'ping' command shows to me between two VMs is : rtt
> >min/avg/max/mdev = 0.233/0.257/0.300/0.024 ms
> >
> >I started 50 netperfs to communicate the other side with the following command:
> >#!/bin/bash
> >
> >for i in $(seq 5000 5050);
> >do
> >netperf -p $i -H [ip addr] -l 60 -t TCP_RR -- -r 64,64 > /dev/null 2>&1 &
> >done
> >
> >The results are around 30423.62 txkB/s. If I remove '-r 64 64', they
> >are still the same/similar.
>
> You have to stress the line by parallel TCP_STREAM instances (50 in my
> case). For consistent results, use -p portnum,locport to specify the
> local port.
Thanks. Even though the results of TCP_RR mode vary sometimes, I can
see a big improvement in the total value of those results under such
circumstances.
With BQL, the throughput is 2159.17
Without BQL, it's 1099.33
Please feel free to add the tag:
Tested-by: Jason Xing <kerneljasonxing@gmail.com>
Thanks,
Jason
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH net-next v2] virtio_net: add support for Byte Queue Limits
2024-06-12 17:08 [PATCH net-next v2] virtio_net: add support for Byte Queue Limits Jiri Pirko
` (2 preceding siblings ...)
2024-06-17 2:34 ` Jason Wang
@ 2024-06-17 16:14 ` Michael S. Tsirkin
2024-06-18 7:52 ` Jiri Pirko
3 siblings, 1 reply; 11+ messages in thread
From: Michael S. Tsirkin @ 2024-06-17 16:14 UTC (permalink / raw)
To: Jiri Pirko
Cc: netdev, davem, edumazet, kuba, pabeni, jasowang, xuanzhuo,
virtualization, ast, daniel, hawk, john.fastabend, dave.taht,
kerneljasonxing, hengqi
On Wed, Jun 12, 2024 at 07:08:51PM +0200, Jiri Pirko wrote:
> From: Jiri Pirko <jiri@nvidia.com>
>
> Add support for Byte Queue Limits (BQL).
>
> Tested on qemu emulated virtio_net device with 1, 2 and 4 queues.
> Tested with fq_codel and pfifo_fast. Super netperf with 50 threads is
> running in background. Netperf TCP_RR results:
>
> NOBQL FQC 1q: 159.56 159.33 158.50 154.31 agv: 157.925
> NOBQL FQC 2q: 184.64 184.96 174.73 174.15 agv: 179.62
> NOBQL FQC 4q: 994.46 441.96 416.50 499.56 agv: 588.12
> NOBQL PFF 1q: 148.68 148.92 145.95 149.48 agv: 148.2575
> NOBQL PFF 2q: 171.86 171.20 170.42 169.42 agv: 170.725
> NOBQL PFF 4q: 1505.23 1137.23 2488.70 3507.99 agv: 2159.7875
> BQL FQC 1q: 1332.80 1297.97 1351.41 1147.57 agv: 1282.4375
> BQL FQC 2q: 768.30 817.72 864.43 974.40 agv: 856.2125
> BQL FQC 4q: 945.66 942.68 878.51 822.82 agv: 897.4175
> BQL PFF 1q: 149.69 151.49 149.40 147.47 agv: 149.5125
> BQL PFF 2q: 2059.32 798.74 1844.12 381.80 agv: 1270.995
> BQL PFF 4q: 1871.98 4420.02 4916.59 13268.16 agv: 6119.1875
>
> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
> ---
> v1->v2:
> - moved netdev_tx_completed_queue() call into __free_old_xmit(),
> propagate use_napi flag to __free_old_xmit() and only call
> netdev_tx_completed_queue() in case it is true
> - added forgotten call to netdev_tx_reset_queue()
> - fixed stats for xdp packets
> - fixed bql accounting when __free_old_xmit() is called from xdp path
> - handle the !use_napi case in start_xmit() kick section
> ---
> drivers/net/virtio_net.c | 50 +++++++++++++++++++++++++---------------
> 1 file changed, 32 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 61a57d134544..5863c663ccab 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -84,7 +84,9 @@ struct virtnet_stat_desc {
>
> struct virtnet_sq_free_stats {
> u64 packets;
> + u64 xdp_packets;
> u64 bytes;
> + u64 xdp_bytes;
> };
>
> struct virtnet_sq_stats {
> @@ -506,29 +508,33 @@ static struct xdp_frame *ptr_to_xdp(void *ptr)
> return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
> }
>
> -static void __free_old_xmit(struct send_queue *sq, bool in_napi,
> +static void __free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
> + bool in_napi, bool use_napi,
> struct virtnet_sq_free_stats *stats)
> {
> unsigned int len;
> void *ptr;
>
> while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
> - ++stats->packets;
> -
> if (!is_xdp_frame(ptr)) {
> struct sk_buff *skb = ptr;
>
> pr_debug("Sent skb %p\n", skb);
>
> + stats->packets++;
> stats->bytes += skb->len;
> napi_consume_skb(skb, in_napi);
> } else {
> struct xdp_frame *frame = ptr_to_xdp(ptr);
>
> - stats->bytes += xdp_get_frame_len(frame);
> + stats->xdp_packets++;
> + stats->xdp_bytes += xdp_get_frame_len(frame);
> xdp_return_frame(frame);
> }
> }
> + if (use_napi)
> + netdev_tx_completed_queue(txq, stats->packets, stats->bytes);
> +
> }
>
> /* Converting between virtqueue no. and kernel tx/rx queue no.
> @@ -955,21 +961,22 @@ static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf)
> virtnet_rq_free_buf(vi, rq, buf);
> }
>
> -static void free_old_xmit(struct send_queue *sq, bool in_napi)
> +static void free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
> + bool in_napi, bool use_napi)
> {
> struct virtnet_sq_free_stats stats = {0};
>
> - __free_old_xmit(sq, in_napi, &stats);
> + __free_old_xmit(sq, txq, in_napi, use_napi, &stats);
>
> /* Avoid overhead when no packets have been processed
> * happens when called speculatively from start_xmit.
> */
> - if (!stats.packets)
> + if (!stats.packets && !stats.xdp_packets)
> return;
>
> u64_stats_update_begin(&sq->stats.syncp);
> - u64_stats_add(&sq->stats.bytes, stats.bytes);
> - u64_stats_add(&sq->stats.packets, stats.packets);
> + u64_stats_add(&sq->stats.bytes, stats.bytes + stats.xdp_bytes);
> + u64_stats_add(&sq->stats.packets, stats.packets + stats.xdp_packets);
> u64_stats_update_end(&sq->stats.syncp);
> }
>
> @@ -1003,7 +1010,9 @@ static void check_sq_full_and_disable(struct virtnet_info *vi,
> * early means 16 slots are typically wasted.
> */
> if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
> - netif_stop_subqueue(dev, qnum);
> + struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
> +
> + netif_tx_stop_queue(txq);
> u64_stats_update_begin(&sq->stats.syncp);
> u64_stats_inc(&sq->stats.stop);
> u64_stats_update_end(&sq->stats.syncp);
> @@ -1012,7 +1021,7 @@ static void check_sq_full_and_disable(struct virtnet_info *vi,
> virtqueue_napi_schedule(&sq->napi, sq->vq);
> } else if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
> /* More just got used, free them then recheck. */
> - free_old_xmit(sq, false);
> + free_old_xmit(sq, txq, false, use_napi);
> if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
> netif_start_subqueue(dev, qnum);
> u64_stats_update_begin(&sq->stats.syncp);
> @@ -1138,7 +1147,8 @@ static int virtnet_xdp_xmit(struct net_device *dev,
> }
>
> /* Free up any pending old buffers before queueing new ones. */
> - __free_old_xmit(sq, false, &stats);
> + __free_old_xmit(sq, netdev_get_tx_queue(dev, sq - vi->sq),
> + false, sq->napi.weight, &stats);
So what happens if sq->napi.weight changes while packet is in the queue?
What prevents that?
>
> for (i = 0; i < n; i++) {
> struct xdp_frame *xdpf = frames[i];
> @@ -2313,7 +2323,7 @@ static void virtnet_poll_cleantx(struct receive_queue *rq)
>
> do {
> virtqueue_disable_cb(sq->vq);
> - free_old_xmit(sq, true);
> + free_old_xmit(sq, txq, true, true);
> } while (unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
>
> if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) {
> @@ -2412,6 +2422,7 @@ static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
> goto err_xdp_reg_mem_model;
>
> virtnet_napi_enable(vi->rq[qp_index].vq, &vi->rq[qp_index].napi);
> + netdev_tx_reset_queue(netdev_get_tx_queue(vi->dev, qp_index));
> virtnet_napi_tx_enable(vi, vi->sq[qp_index].vq, &vi->sq[qp_index].napi);
>
> return 0;
> @@ -2471,7 +2482,7 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget)
> txq = netdev_get_tx_queue(vi->dev, index);
> __netif_tx_lock(txq, raw_smp_processor_id());
> virtqueue_disable_cb(sq->vq);
> - free_old_xmit(sq, true);
> + free_old_xmit(sq, txq, true, true);
>
> if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) {
> if (netif_tx_queue_stopped(txq)) {
> @@ -2559,17 +2570,18 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
> struct send_queue *sq = &vi->sq[qnum];
> int err;
> struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
> - bool kick = !netdev_xmit_more();
> + bool xmit_more = netdev_xmit_more();
> bool use_napi = sq->napi.weight;
> + bool kick;
>
> /* Free up any pending old buffers before queueing new ones. */
> do {
> if (use_napi)
> virtqueue_disable_cb(sq->vq);
>
> - free_old_xmit(sq, false);
> + free_old_xmit(sq, txq, false, use_napi);
>
> - } while (use_napi && kick &&
> + } while (use_napi && !xmit_more &&
> unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
>
> /* timestamp packet in software */
> @@ -2598,7 +2610,9 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
>
> check_sq_full_and_disable(vi, dev, sq);
>
> - if (kick || netif_xmit_stopped(txq)) {
> + kick = use_napi ? __netdev_tx_sent_queue(txq, skb->len, xmit_more) :
> + !xmit_more && netif_xmit_stopped(txq);
> + if (kick) {
> if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
> u64_stats_update_begin(&sq->stats.syncp);
> u64_stats_inc(&sq->stats.kicks);
> --
> 2.45.1
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH net-next v2] virtio_net: add support for Byte Queue Limits
2024-06-17 9:18 ` Jiri Pirko
@ 2024-06-18 0:53 ` Jason Wang
2024-06-18 7:52 ` Jiri Pirko
0 siblings, 1 reply; 11+ messages in thread
From: Jason Wang @ 2024-06-18 0:53 UTC (permalink / raw)
To: Jiri Pirko
Cc: netdev, davem, edumazet, kuba, pabeni, mst, xuanzhuo,
virtualization, ast, daniel, hawk, john.fastabend, dave.taht,
kerneljasonxing, hengqi
On Mon, Jun 17, 2024 at 5:18 PM Jiri Pirko <jiri@resnulli.us> wrote:
>
> Mon, Jun 17, 2024 at 04:34:26AM CEST, jasowang@redhat.com wrote:
> >On Thu, Jun 13, 2024 at 1:09 AM Jiri Pirko <jiri@resnulli.us> wrote:
> >>
> >> From: Jiri Pirko <jiri@nvidia.com>
> >>
> >> Add support for Byte Queue Limits (BQL).
> >>
> >> Tested on qemu emulated virtio_net device with 1, 2 and 4 queues.
> >> Tested with fq_codel and pfifo_fast. Super netperf with 50 threads is
> >> running in background. Netperf TCP_RR results:
> >>
> >> NOBQL FQC 1q: 159.56 159.33 158.50 154.31 agv: 157.925
> >> NOBQL FQC 2q: 184.64 184.96 174.73 174.15 agv: 179.62
> >> NOBQL FQC 4q: 994.46 441.96 416.50 499.56 agv: 588.12
> >> NOBQL PFF 1q: 148.68 148.92 145.95 149.48 agv: 148.2575
> >> NOBQL PFF 2q: 171.86 171.20 170.42 169.42 agv: 170.725
> >> NOBQL PFF 4q: 1505.23 1137.23 2488.70 3507.99 agv: 2159.7875
> >> BQL FQC 1q: 1332.80 1297.97 1351.41 1147.57 agv: 1282.4375
> >> BQL FQC 2q: 768.30 817.72 864.43 974.40 agv: 856.2125
> >> BQL FQC 4q: 945.66 942.68 878.51 822.82 agv: 897.4175
> >> BQL PFF 1q: 149.69 151.49 149.40 147.47 agv: 149.5125
> >> BQL PFF 2q: 2059.32 798.74 1844.12 381.80 agv: 1270.995
> >> BQL PFF 4q: 1871.98 4420.02 4916.59 13268.16 agv: 6119.1875
> >>
> >> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
> >> ---
> >> v1->v2:
> >> - moved netdev_tx_completed_queue() call into __free_old_xmit(),
> >> propagate use_napi flag to __free_old_xmit() and only call
> >> netdev_tx_completed_queue() in case it is true
> >> - added forgotten call to netdev_tx_reset_queue()
> >> - fixed stats for xdp packets
> >> - fixed bql accounting when __free_old_xmit() is called from xdp path
> >> - handle the !use_napi case in start_xmit() kick section
> >> ---
> >> drivers/net/virtio_net.c | 50 +++++++++++++++++++++++++---------------
> >> 1 file changed, 32 insertions(+), 18 deletions(-)
> >>
> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> >> index 61a57d134544..5863c663ccab 100644
> >> --- a/drivers/net/virtio_net.c
> >> +++ b/drivers/net/virtio_net.c
> >> @@ -84,7 +84,9 @@ struct virtnet_stat_desc {
> >>
> >> struct virtnet_sq_free_stats {
> >> u64 packets;
> >> + u64 xdp_packets;
> >> u64 bytes;
> >> + u64 xdp_bytes;
> >> };
> >>
> >> struct virtnet_sq_stats {
> >> @@ -506,29 +508,33 @@ static struct xdp_frame *ptr_to_xdp(void *ptr)
> >> return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
> >> }
> >>
> >> -static void __free_old_xmit(struct send_queue *sq, bool in_napi,
> >> +static void __free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
> >> + bool in_napi, bool use_napi,
> >> struct virtnet_sq_free_stats *stats)
> >> {
> >> unsigned int len;
> >> void *ptr;
> >>
> >> while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
> >> - ++stats->packets;
> >> -
> >> if (!is_xdp_frame(ptr)) {
> >> struct sk_buff *skb = ptr;
> >>
> >> pr_debug("Sent skb %p\n", skb);
> >>
> >> + stats->packets++;
> >> stats->bytes += skb->len;
> >> napi_consume_skb(skb, in_napi);
> >> } else {
> >> struct xdp_frame *frame = ptr_to_xdp(ptr);
> >>
> >> - stats->bytes += xdp_get_frame_len(frame);
> >> + stats->xdp_packets++;
> >> + stats->xdp_bytes += xdp_get_frame_len(frame);
> >> xdp_return_frame(frame);
> >> }
> >> }
> >> + if (use_napi)
> >> + netdev_tx_completed_queue(txq, stats->packets, stats->bytes);
> >> +
> >> }
> >
> >I wonder if this works correctly, for example NAPI could be enabled
> >after queued but before sent. So __netdev_tx_sent_queue() is not
> >called before.
>
> How is that possible? Napi weight can't change when link is up. Or am I
> missing something?
Something like this:
1) packet were queued
2) if down
3) enable NAPI
4) if up
5) packet were sent
?
Thanks
>
> >
> >Thanks
> >
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH net-next v2] virtio_net: add support for Byte Queue Limits
2024-06-17 16:14 ` Michael S. Tsirkin
@ 2024-06-18 7:52 ` Jiri Pirko
0 siblings, 0 replies; 11+ messages in thread
From: Jiri Pirko @ 2024-06-18 7:52 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: netdev, davem, edumazet, kuba, pabeni, jasowang, xuanzhuo,
virtualization, ast, daniel, hawk, john.fastabend, dave.taht,
kerneljasonxing, hengqi
Mon, Jun 17, 2024 at 06:14:11PM CEST, mst@redhat.com wrote:
>On Wed, Jun 12, 2024 at 07:08:51PM +0200, Jiri Pirko wrote:
>> From: Jiri Pirko <jiri@nvidia.com>
>>
>> Add support for Byte Queue Limits (BQL).
>>
>> Tested on qemu emulated virtio_net device with 1, 2 and 4 queues.
>> Tested with fq_codel and pfifo_fast. Super netperf with 50 threads is
>> running in background. Netperf TCP_RR results:
>>
>> NOBQL FQC 1q: 159.56 159.33 158.50 154.31 agv: 157.925
>> NOBQL FQC 2q: 184.64 184.96 174.73 174.15 agv: 179.62
>> NOBQL FQC 4q: 994.46 441.96 416.50 499.56 agv: 588.12
>> NOBQL PFF 1q: 148.68 148.92 145.95 149.48 agv: 148.2575
>> NOBQL PFF 2q: 171.86 171.20 170.42 169.42 agv: 170.725
>> NOBQL PFF 4q: 1505.23 1137.23 2488.70 3507.99 agv: 2159.7875
>> BQL FQC 1q: 1332.80 1297.97 1351.41 1147.57 agv: 1282.4375
>> BQL FQC 2q: 768.30 817.72 864.43 974.40 agv: 856.2125
>> BQL FQC 4q: 945.66 942.68 878.51 822.82 agv: 897.4175
>> BQL PFF 1q: 149.69 151.49 149.40 147.47 agv: 149.5125
>> BQL PFF 2q: 2059.32 798.74 1844.12 381.80 agv: 1270.995
>> BQL PFF 4q: 1871.98 4420.02 4916.59 13268.16 agv: 6119.1875
>>
>> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
>> ---
>> v1->v2:
>> - moved netdev_tx_completed_queue() call into __free_old_xmit(),
>> propagate use_napi flag to __free_old_xmit() and only call
>> netdev_tx_completed_queue() in case it is true
>> - added forgotten call to netdev_tx_reset_queue()
>> - fixed stats for xdp packets
>> - fixed bql accounting when __free_old_xmit() is called from xdp path
>> - handle the !use_napi case in start_xmit() kick section
>> ---
>> drivers/net/virtio_net.c | 50 +++++++++++++++++++++++++---------------
>> 1 file changed, 32 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> index 61a57d134544..5863c663ccab 100644
>> --- a/drivers/net/virtio_net.c
>> +++ b/drivers/net/virtio_net.c
>> @@ -84,7 +84,9 @@ struct virtnet_stat_desc {
>>
>> struct virtnet_sq_free_stats {
>> u64 packets;
>> + u64 xdp_packets;
>> u64 bytes;
>> + u64 xdp_bytes;
>> };
>>
>> struct virtnet_sq_stats {
>> @@ -506,29 +508,33 @@ static struct xdp_frame *ptr_to_xdp(void *ptr)
>> return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
>> }
>>
>> -static void __free_old_xmit(struct send_queue *sq, bool in_napi,
>> +static void __free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
>> + bool in_napi, bool use_napi,
>> struct virtnet_sq_free_stats *stats)
>> {
>> unsigned int len;
>> void *ptr;
>>
>> while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
>> - ++stats->packets;
>> -
>> if (!is_xdp_frame(ptr)) {
>> struct sk_buff *skb = ptr;
>>
>> pr_debug("Sent skb %p\n", skb);
>>
>> + stats->packets++;
>> stats->bytes += skb->len;
>> napi_consume_skb(skb, in_napi);
>> } else {
>> struct xdp_frame *frame = ptr_to_xdp(ptr);
>>
>> - stats->bytes += xdp_get_frame_len(frame);
>> + stats->xdp_packets++;
>> + stats->xdp_bytes += xdp_get_frame_len(frame);
>> xdp_return_frame(frame);
>> }
>> }
>> + if (use_napi)
>> + netdev_tx_completed_queue(txq, stats->packets, stats->bytes);
>> +
>> }
>>
>> /* Converting between virtqueue no. and kernel tx/rx queue no.
>> @@ -955,21 +961,22 @@ static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf)
>> virtnet_rq_free_buf(vi, rq, buf);
>> }
>>
>> -static void free_old_xmit(struct send_queue *sq, bool in_napi)
>> +static void free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
>> + bool in_napi, bool use_napi)
>> {
>> struct virtnet_sq_free_stats stats = {0};
>>
>> - __free_old_xmit(sq, in_napi, &stats);
>> + __free_old_xmit(sq, txq, in_napi, use_napi, &stats);
>>
>> /* Avoid overhead when no packets have been processed
>> * happens when called speculatively from start_xmit.
>> */
>> - if (!stats.packets)
>> + if (!stats.packets && !stats.xdp_packets)
>> return;
>>
>> u64_stats_update_begin(&sq->stats.syncp);
>> - u64_stats_add(&sq->stats.bytes, stats.bytes);
>> - u64_stats_add(&sq->stats.packets, stats.packets);
>> + u64_stats_add(&sq->stats.bytes, stats.bytes + stats.xdp_bytes);
>> + u64_stats_add(&sq->stats.packets, stats.packets + stats.xdp_packets);
>> u64_stats_update_end(&sq->stats.syncp);
>> }
>>
>> @@ -1003,7 +1010,9 @@ static void check_sq_full_and_disable(struct virtnet_info *vi,
>> * early means 16 slots are typically wasted.
>> */
>> if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
>> - netif_stop_subqueue(dev, qnum);
>> + struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
>> +
>> + netif_tx_stop_queue(txq);
>> u64_stats_update_begin(&sq->stats.syncp);
>> u64_stats_inc(&sq->stats.stop);
>> u64_stats_update_end(&sq->stats.syncp);
>> @@ -1012,7 +1021,7 @@ static void check_sq_full_and_disable(struct virtnet_info *vi,
>> virtqueue_napi_schedule(&sq->napi, sq->vq);
>> } else if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
>> /* More just got used, free them then recheck. */
>> - free_old_xmit(sq, false);
>> + free_old_xmit(sq, txq, false, use_napi);
>> if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
>> netif_start_subqueue(dev, qnum);
>> u64_stats_update_begin(&sq->stats.syncp);
>> @@ -1138,7 +1147,8 @@ static int virtnet_xdp_xmit(struct net_device *dev,
>> }
>>
>> /* Free up any pending old buffers before queueing new ones. */
>> - __free_old_xmit(sq, false, &stats);
>> + __free_old_xmit(sq, netdev_get_tx_queue(dev, sq - vi->sq),
>> + false, sq->napi.weight, &stats);
>
>
>So what happens if sq->napi.weight changes while packet is in the queue?
>What prevents that?
Sigh. You are correct. That is what Jason points out as well.
>
>
>
>>
>> for (i = 0; i < n; i++) {
>> struct xdp_frame *xdpf = frames[i];
>> @@ -2313,7 +2323,7 @@ static void virtnet_poll_cleantx(struct receive_queue *rq)
>>
>> do {
>> virtqueue_disable_cb(sq->vq);
>> - free_old_xmit(sq, true);
>> + free_old_xmit(sq, txq, true, true);
>> } while (unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
>>
>> if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) {
>> @@ -2412,6 +2422,7 @@ static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
>> goto err_xdp_reg_mem_model;
>>
>> virtnet_napi_enable(vi->rq[qp_index].vq, &vi->rq[qp_index].napi);
>> + netdev_tx_reset_queue(netdev_get_tx_queue(vi->dev, qp_index));
>> virtnet_napi_tx_enable(vi, vi->sq[qp_index].vq, &vi->sq[qp_index].napi);
>>
>> return 0;
>> @@ -2471,7 +2482,7 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget)
>> txq = netdev_get_tx_queue(vi->dev, index);
>> __netif_tx_lock(txq, raw_smp_processor_id());
>> virtqueue_disable_cb(sq->vq);
>> - free_old_xmit(sq, true);
>> + free_old_xmit(sq, txq, true, true);
>>
>> if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) {
>> if (netif_tx_queue_stopped(txq)) {
>> @@ -2559,17 +2570,18 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
>> struct send_queue *sq = &vi->sq[qnum];
>> int err;
>> struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
>> - bool kick = !netdev_xmit_more();
>> + bool xmit_more = netdev_xmit_more();
>> bool use_napi = sq->napi.weight;
>> + bool kick;
>>
>> /* Free up any pending old buffers before queueing new ones. */
>> do {
>> if (use_napi)
>> virtqueue_disable_cb(sq->vq);
>>
>> - free_old_xmit(sq, false);
>> + free_old_xmit(sq, txq, false, use_napi);
>>
>> - } while (use_napi && kick &&
>> + } while (use_napi && !xmit_more &&
>> unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
>>
>> /* timestamp packet in software */
>> @@ -2598,7 +2610,9 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
>>
>> check_sq_full_and_disable(vi, dev, sq);
>>
>> - if (kick || netif_xmit_stopped(txq)) {
>> + kick = use_napi ? __netdev_tx_sent_queue(txq, skb->len, xmit_more) :
>> + !xmit_more && netif_xmit_stopped(txq);
>> + if (kick) {
>> if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) {
>> u64_stats_update_begin(&sq->stats.syncp);
>> u64_stats_inc(&sq->stats.kicks);
>> --
>> 2.45.1
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH net-next v2] virtio_net: add support for Byte Queue Limits
2024-06-18 0:53 ` Jason Wang
@ 2024-06-18 7:52 ` Jiri Pirko
0 siblings, 0 replies; 11+ messages in thread
From: Jiri Pirko @ 2024-06-18 7:52 UTC (permalink / raw)
To: Jason Wang
Cc: netdev, davem, edumazet, kuba, pabeni, mst, xuanzhuo,
virtualization, ast, daniel, hawk, john.fastabend, dave.taht,
kerneljasonxing, hengqi
Tue, Jun 18, 2024 at 02:53:42AM CEST, jasowang@redhat.com wrote:
>On Mon, Jun 17, 2024 at 5:18 PM Jiri Pirko <jiri@resnulli.us> wrote:
>>
>> Mon, Jun 17, 2024 at 04:34:26AM CEST, jasowang@redhat.com wrote:
>> >On Thu, Jun 13, 2024 at 1:09 AM Jiri Pirko <jiri@resnulli.us> wrote:
>> >>
>> >> From: Jiri Pirko <jiri@nvidia.com>
>> >>
>> >> Add support for Byte Queue Limits (BQL).
>> >>
>> >> Tested on qemu emulated virtio_net device with 1, 2 and 4 queues.
>> >> Tested with fq_codel and pfifo_fast. Super netperf with 50 threads is
>> >> running in background. Netperf TCP_RR results:
>> >>
>> >> NOBQL FQC 1q: 159.56 159.33 158.50 154.31 agv: 157.925
>> >> NOBQL FQC 2q: 184.64 184.96 174.73 174.15 agv: 179.62
>> >> NOBQL FQC 4q: 994.46 441.96 416.50 499.56 agv: 588.12
>> >> NOBQL PFF 1q: 148.68 148.92 145.95 149.48 agv: 148.2575
>> >> NOBQL PFF 2q: 171.86 171.20 170.42 169.42 agv: 170.725
>> >> NOBQL PFF 4q: 1505.23 1137.23 2488.70 3507.99 agv: 2159.7875
>> >> BQL FQC 1q: 1332.80 1297.97 1351.41 1147.57 agv: 1282.4375
>> >> BQL FQC 2q: 768.30 817.72 864.43 974.40 agv: 856.2125
>> >> BQL FQC 4q: 945.66 942.68 878.51 822.82 agv: 897.4175
>> >> BQL PFF 1q: 149.69 151.49 149.40 147.47 agv: 149.5125
>> >> BQL PFF 2q: 2059.32 798.74 1844.12 381.80 agv: 1270.995
>> >> BQL PFF 4q: 1871.98 4420.02 4916.59 13268.16 agv: 6119.1875
>> >>
>> >> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
>> >> ---
>> >> v1->v2:
>> >> - moved netdev_tx_completed_queue() call into __free_old_xmit(),
>> >> propagate use_napi flag to __free_old_xmit() and only call
>> >> netdev_tx_completed_queue() in case it is true
>> >> - added forgotten call to netdev_tx_reset_queue()
>> >> - fixed stats for xdp packets
>> >> - fixed bql accounting when __free_old_xmit() is called from xdp path
>> >> - handle the !use_napi case in start_xmit() kick section
>> >> ---
>> >> drivers/net/virtio_net.c | 50 +++++++++++++++++++++++++---------------
>> >> 1 file changed, 32 insertions(+), 18 deletions(-)
>> >>
>> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> >> index 61a57d134544..5863c663ccab 100644
>> >> --- a/drivers/net/virtio_net.c
>> >> +++ b/drivers/net/virtio_net.c
>> >> @@ -84,7 +84,9 @@ struct virtnet_stat_desc {
>> >>
>> >> struct virtnet_sq_free_stats {
>> >> u64 packets;
>> >> + u64 xdp_packets;
>> >> u64 bytes;
>> >> + u64 xdp_bytes;
>> >> };
>> >>
>> >> struct virtnet_sq_stats {
>> >> @@ -506,29 +508,33 @@ static struct xdp_frame *ptr_to_xdp(void *ptr)
>> >> return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
>> >> }
>> >>
>> >> -static void __free_old_xmit(struct send_queue *sq, bool in_napi,
>> >> +static void __free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
>> >> + bool in_napi, bool use_napi,
>> >> struct virtnet_sq_free_stats *stats)
>> >> {
>> >> unsigned int len;
>> >> void *ptr;
>> >>
>> >> while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
>> >> - ++stats->packets;
>> >> -
>> >> if (!is_xdp_frame(ptr)) {
>> >> struct sk_buff *skb = ptr;
>> >>
>> >> pr_debug("Sent skb %p\n", skb);
>> >>
>> >> + stats->packets++;
>> >> stats->bytes += skb->len;
>> >> napi_consume_skb(skb, in_napi);
>> >> } else {
>> >> struct xdp_frame *frame = ptr_to_xdp(ptr);
>> >>
>> >> - stats->bytes += xdp_get_frame_len(frame);
>> >> + stats->xdp_packets++;
>> >> + stats->xdp_bytes += xdp_get_frame_len(frame);
>> >> xdp_return_frame(frame);
>> >> }
>> >> }
>> >> + if (use_napi)
>> >> + netdev_tx_completed_queue(txq, stats->packets, stats->bytes);
>> >> +
>> >> }
>> >
>> >I wonder if this works correctly, for example NAPI could be enabled
>> >after queued but before sent. So __netdev_tx_sent_queue() is not
>> >called before.
>>
>> How is that possible? Napi weight can't change when link is up. Or am I
>> missing something?
>
>Something like this:
>
>1) packet were queued
>2) if down
>3) enable NAPI
>4) if up
>5) packet were sent
Gotcha, will try to fix. Thanks!
>
>?
>
>Thanks
>
>>
>> >
>> >Thanks
>> >
>>
>
^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2024-06-18 7:52 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-06-12 17:08 [PATCH net-next v2] virtio_net: add support for Byte Queue Limits Jiri Pirko
2024-06-12 22:30 ` Michael S. Tsirkin
2024-06-14 9:54 ` Jason Xing
2024-06-17 9:15 ` Jiri Pirko
2024-06-17 15:47 ` Jason Xing
2024-06-17 2:34 ` Jason Wang
2024-06-17 9:18 ` Jiri Pirko
2024-06-18 0:53 ` Jason Wang
2024-06-18 7:52 ` Jiri Pirko
2024-06-17 16:14 ` Michael S. Tsirkin
2024-06-18 7:52 ` Jiri Pirko
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