* [PATCH] virtio_net: add rx-alloc-fail counter
@ 2026-08-11 9:10 Longjun Tang
2026-08-11 15:40 ` Jakub Kicinski
0 siblings, 1 reply; 3+ messages in thread
From: Longjun Tang @ 2026-08-11 9:10 UTC (permalink / raw)
To: mst, kuba, jasowangio; +Cc: xuanzhuo, virtualization, tanglongjun, lange_tang
From: tanglongjun <tanglongjun@kylinos.cn>
Count buffer and skb allocation failures on the rx queue and
report them via rx-alloc-fail in netdev qstats.
$ ./tools/net/ynl/ynltool/ynltool qstats show --json scope queue
[{"ifname":"ens3",
"ifindex":2,
"queue-type":"rx",
"queue-id":0,
"rx":{"packets":3722,"bytes":374806,"alloc-fail":0}},
{"ifname":"ens3",
"ifindex":2,
"queue-type":"tx",
"queue-id":0,
"tx":{"packets":622,"bytes":77495,"stop":0,"wake":0}}]
Signed-off-by: Longjun Tang <tanglongjun@kylinos.cn>
---
drivers/net/virtio_net.c | 32 ++++++++++++++++++++++++--------
1 file changed, 24 insertions(+), 8 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 3e2a5876c6c8..f9d15c618d3b 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -125,6 +125,7 @@ struct virtnet_rq_stats {
u64_stats_t packets;
u64_stats_t bytes;
u64_stats_t drops;
+ u64_stats_t alloc_fail;
u64_stats_t xdp_packets;
u64_stats_t xdp_tx;
u64_stats_t xdp_redirects;
@@ -173,8 +174,9 @@ static const struct virtnet_stat_desc virtnet_sq_stats_desc_qstat[] = {
};
static const struct virtnet_stat_desc virtnet_rq_stats_desc_qstat[] = {
- VIRTNET_RQ_STAT_QSTAT("packets", packets),
- VIRTNET_RQ_STAT_QSTAT("bytes", bytes),
+ VIRTNET_RQ_STAT_QSTAT("packets", packets),
+ VIRTNET_RQ_STAT_QSTAT("bytes", bytes),
+ VIRTNET_RQ_STAT_QSTAT("alloc_fail", alloc_fail),
};
#define VIRTNET_STATS_DESC_CQ(name) \
@@ -1917,8 +1919,10 @@ static struct sk_buff *receive_small_xdp(struct net_device *dev,
}
skb = virtnet_build_skb(buf, buflen, xdp.data - buf, len);
- if (unlikely(!skb))
+ if (unlikely(!skb)) {
+ u64_stats_inc(&stats->alloc_fail);
goto err;
+ }
if (metasize)
skb_metadata_set(skb, metasize);
@@ -1985,6 +1989,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
return skb;
}
+ u64_stats_inc(&stats->alloc_fail);
err:
u64_stats_inc(&stats->drops);
page_pool_put_page(rq->page_pool, page, -1, true);
@@ -2016,8 +2021,10 @@ static struct sk_buff *receive_big(struct net_device *dev,
skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, 0);
u64_stats_add(&stats->bytes, len - vi->hdr_len);
- if (unlikely(!skb))
+ if (unlikely(!skb)) {
+ u64_stats_inc(&stats->alloc_fail);
goto err;
+ }
return skb;
@@ -2298,8 +2305,10 @@ static struct sk_buff *receive_mergeable_xdp(struct net_device *dev,
switch (act) {
case XDP_PASS:
head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz);
- if (unlikely(!head_skb))
+ if (unlikely(!head_skb)) {
+ u64_stats_inc(&stats->alloc_fail);
break;
+ }
skb_mark_for_recycle(head_skb);
return head_skb;
@@ -2414,8 +2423,10 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
head_skb = page_to_skb(vi, rq, page, offset, len, truesize, headroom);
curr_skb = head_skb;
- if (unlikely(!curr_skb))
+ if (unlikely(!curr_skb)) {
+ u64_stats_inc(&stats->alloc_fail);
goto err_skb;
+ }
skb_mark_for_recycle(head_skb);
while (--num_buf) {
@@ -2444,8 +2455,10 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
truesize = mergeable_ctx_to_truesize(ctx);
curr_skb = virtnet_skb_append_frag(rq, head_skb, curr_skb, page,
buf, len, truesize);
- if (!curr_skb)
+ if (!curr_skb) {
+ u64_stats_inc(&stats->alloc_fail);
goto err_skb;
+ }
}
ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
@@ -2928,12 +2941,14 @@ static int virtnet_receive(struct receive_queue *rq, int budget,
u64_stats_set(&stats.packets, packets);
if (rq->vq->num_free > min((unsigned int)budget, virtqueue_get_vring_size(rq->vq)) / 2) {
- if (!try_fill_recv(vi, rq, GFP_ATOMIC))
+ if (!try_fill_recv(vi, rq, GFP_ATOMIC)) {
/* We need to retry refilling in the next NAPI poll so
* we must return budget to make sure the NAPI is
* repolled.
*/
packets = budget;
+ u64_stats_inc(&stats.alloc_fail);
+ }
}
u64_stats_update_begin(&rq->stats.syncp);
@@ -2948,6 +2963,7 @@ static int virtnet_receive(struct receive_queue *rq, int budget,
u64_stats_add(&rq->stats.packets, u64_stats_read(&stats.packets));
u64_stats_add(&rq->stats.bytes, u64_stats_read(&stats.bytes));
+ u64_stats_add(&rq->stats.alloc_fail, u64_stats_read(&stats.alloc_fail));
u64_stats_update_end(&rq->stats.syncp);
--
2.51.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] virtio_net: add rx-alloc-fail counter
2026-08-11 9:10 [PATCH] virtio_net: add rx-alloc-fail counter Longjun Tang
@ 2026-08-11 15:40 ` Jakub Kicinski
0 siblings, 0 replies; 3+ messages in thread
From: Jakub Kicinski @ 2026-08-11 15:40 UTC (permalink / raw)
To: Longjun Tang; +Cc: mst, jasowangio, xuanzhuo, virtualization, tanglongjun
On Tue, 11 Aug 2026 17:10:45 +0800 Longjun Tang wrote:
> Count buffer and skb allocation failures on the rx queue and
> report them via rx-alloc-fail in netdev qstats.
please repost and CC netdev@ (if you haven't already)
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH] virtio_net: add rx-alloc-fail counter
@ 2026-08-12 1:22 Longjun Tang
0 siblings, 0 replies; 3+ messages in thread
From: Longjun Tang @ 2026-08-12 1:22 UTC (permalink / raw)
To: mst, kuba, jasowangio
Cc: xuanzhuo, virtualization, netdev, tanglongjun, lange_tang
From: tanglongjun <tanglongjun@kylinos.cn>
Count buffer and skb allocation failures on the rx queue and
report them via rx-alloc-fail in netdev qstats.
$ ./tools/net/ynl/ynltool/ynltool qstats show --json scope queue
[{"ifname":"ens3",
"ifindex":2,
"queue-type":"rx",
"queue-id":0,
"rx":{"packets":3722,"bytes":374806,"alloc-fail":0}},
{"ifname":"ens3",
"ifindex":2,
"queue-type":"tx",
"queue-id":0,
"tx":{"packets":622,"bytes":77495,"stop":0,"wake":0}}]
Signed-off-by: Longjun Tang <tanglongjun@kylinos.cn>
---
drivers/net/virtio_net.c | 32 ++++++++++++++++++++++++--------
1 file changed, 24 insertions(+), 8 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 3e2a5876c6c8..f9d15c618d3b 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -125,6 +125,7 @@ struct virtnet_rq_stats {
u64_stats_t packets;
u64_stats_t bytes;
u64_stats_t drops;
+ u64_stats_t alloc_fail;
u64_stats_t xdp_packets;
u64_stats_t xdp_tx;
u64_stats_t xdp_redirects;
@@ -173,8 +174,9 @@ static const struct virtnet_stat_desc virtnet_sq_stats_desc_qstat[] = {
};
static const struct virtnet_stat_desc virtnet_rq_stats_desc_qstat[] = {
- VIRTNET_RQ_STAT_QSTAT("packets", packets),
- VIRTNET_RQ_STAT_QSTAT("bytes", bytes),
+ VIRTNET_RQ_STAT_QSTAT("packets", packets),
+ VIRTNET_RQ_STAT_QSTAT("bytes", bytes),
+ VIRTNET_RQ_STAT_QSTAT("alloc_fail", alloc_fail),
};
#define VIRTNET_STATS_DESC_CQ(name) \
@@ -1917,8 +1919,10 @@ static struct sk_buff *receive_small_xdp(struct net_device *dev,
}
skb = virtnet_build_skb(buf, buflen, xdp.data - buf, len);
- if (unlikely(!skb))
+ if (unlikely(!skb)) {
+ u64_stats_inc(&stats->alloc_fail);
goto err;
+ }
if (metasize)
skb_metadata_set(skb, metasize);
@@ -1985,6 +1989,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
return skb;
}
+ u64_stats_inc(&stats->alloc_fail);
err:
u64_stats_inc(&stats->drops);
page_pool_put_page(rq->page_pool, page, -1, true);
@@ -2016,8 +2021,10 @@ static struct sk_buff *receive_big(struct net_device *dev,
skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, 0);
u64_stats_add(&stats->bytes, len - vi->hdr_len);
- if (unlikely(!skb))
+ if (unlikely(!skb)) {
+ u64_stats_inc(&stats->alloc_fail);
goto err;
+ }
return skb;
@@ -2298,8 +2305,10 @@ static struct sk_buff *receive_mergeable_xdp(struct net_device *dev,
switch (act) {
case XDP_PASS:
head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz);
- if (unlikely(!head_skb))
+ if (unlikely(!head_skb)) {
+ u64_stats_inc(&stats->alloc_fail);
break;
+ }
skb_mark_for_recycle(head_skb);
return head_skb;
@@ -2414,8 +2423,10 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
head_skb = page_to_skb(vi, rq, page, offset, len, truesize, headroom);
curr_skb = head_skb;
- if (unlikely(!curr_skb))
+ if (unlikely(!curr_skb)) {
+ u64_stats_inc(&stats->alloc_fail);
goto err_skb;
+ }
skb_mark_for_recycle(head_skb);
while (--num_buf) {
@@ -2444,8 +2455,10 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
truesize = mergeable_ctx_to_truesize(ctx);
curr_skb = virtnet_skb_append_frag(rq, head_skb, curr_skb, page,
buf, len, truesize);
- if (!curr_skb)
+ if (!curr_skb) {
+ u64_stats_inc(&stats->alloc_fail);
goto err_skb;
+ }
}
ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
@@ -2928,12 +2941,14 @@ static int virtnet_receive(struct receive_queue *rq, int budget,
u64_stats_set(&stats.packets, packets);
if (rq->vq->num_free > min((unsigned int)budget, virtqueue_get_vring_size(rq->vq)) / 2) {
- if (!try_fill_recv(vi, rq, GFP_ATOMIC))
+ if (!try_fill_recv(vi, rq, GFP_ATOMIC)) {
/* We need to retry refilling in the next NAPI poll so
* we must return budget to make sure the NAPI is
* repolled.
*/
packets = budget;
+ u64_stats_inc(&stats.alloc_fail);
+ }
}
u64_stats_update_begin(&rq->stats.syncp);
@@ -2948,6 +2963,7 @@ static int virtnet_receive(struct receive_queue *rq, int budget,
u64_stats_add(&rq->stats.packets, u64_stats_read(&stats.packets));
u64_stats_add(&rq->stats.bytes, u64_stats_read(&stats.bytes));
+ u64_stats_add(&rq->stats.alloc_fail, u64_stats_read(&stats.alloc_fail));
u64_stats_update_end(&rq->stats.syncp);
--
2.51.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-08-12 1:23 UTC | newest]
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2026-08-11 9:10 [PATCH] virtio_net: add rx-alloc-fail counter Longjun Tang
2026-08-11 15:40 ` Jakub Kicinski
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2026-08-12 1:22 Longjun Tang
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