In ovs_vport_get_upcall_stats(), some statistics protected by
u64_stats_sync, are read and accumulated in ignorance of possible
u64_stats_fetch_retry() events. These statistics are already accumulated
by u64_stats_inc(). Fix this by reading them into temporary variables
first.

Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets")
Signed-off-by: David Yang <mmyangfl@gmail.com>
---
 net/openvswitch/vport.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index 6bbbc16ab778..bc46d661b527 100644
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c
@@ -319,13 +319,17 @@ int ovs_vport_get_upcall_stats(struct vport *vport, struct sk_buff *skb)
 	for_each_possible_cpu(i) {
 		const struct vport_upcall_stats_percpu *stats;
 		unsigned int start;
+		__u64 n_success;
+		__u64 n_fail;
 
 		stats = per_cpu_ptr(vport->upcall_stats, i);
 		do {
 			start = u64_stats_fetch_begin(&stats->syncp);
-			tx_success += u64_stats_read(&stats->n_success);
-			tx_fail += u64_stats_read(&stats->n_fail);
+			n_success = u64_stats_read(&stats->n_success);
+			n_fail = u64_stats_read(&stats->n_fail);
 		} while (u64_stats_fetch_retry(&stats->syncp, start));
+		tx_success += n_success;
+		tx_fail += n_fail;
 	}
 
 	nla = nla_nest_start_noflag(skb, OVS_VPORT_ATTR_UPCALL_STATS);
-- 
2.51.0

On 1/19/26 7:13 PM, David Yang wrote:
> In ovs_vport_get_upcall_stats(), some statistics protected by
> u64_stats_sync, are read and accumulated in ignorance of possible
> u64_stats_fetch_retry() events. These statistics are already accumulated
> by u64_stats_inc(). Fix this by reading them into temporary variables
> first.
> 
> Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets")
> Signed-off-by: David Yang <mmyangfl@gmail.com>
> ---
>  net/openvswitch/vport.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 

Hi, David.  The change makes sense to me, thanks!

> diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
> index 6bbbc16ab778..bc46d661b527 100644
> --- a/net/openvswitch/vport.c
> +++ b/net/openvswitch/vport.c
> @@ -319,13 +319,17 @@ int ovs_vport_get_upcall_stats(struct vport *vport, struct sk_buff *skb)
>  	for_each_possible_cpu(i) {
>  		const struct vport_upcall_stats_percpu *stats;
>  		unsigned int start;
> +		__u64 n_success;
> +		__u64 n_fail;

In addition to Eric's suggestion on using plain u64, you may also
put these two together on the same line, right above the definition
for 'start', to keep the reverse x-mass tree ordering.

>  
>  		stats = per_cpu_ptr(vport->upcall_stats, i);
>  		do {
>  			start = u64_stats_fetch_begin(&stats->syncp);
> -			tx_success += u64_stats_read(&stats->n_success);
> -			tx_fail += u64_stats_read(&stats->n_fail);
> +			n_success = u64_stats_read(&stats->n_success);
> +			n_fail = u64_stats_read(&stats->n_fail);
>  		} while (u64_stats_fetch_retry(&stats->syncp, start));
> +		tx_success += n_success;
> +		tx_fail += n_fail;
>  	}
>  
>  	nla = nla_nest_start_noflag(skb, OVS_VPORT_ATTR_UPCALL_STATS);

Best regards, Ilya Maximets.

On Mon, Jan 19, 2026 at 7:14 PM David Yang <mmyangfl@gmail.com> wrote:
>
> In ovs_vport_get_upcall_stats(), some statistics protected by
> u64_stats_sync, are read and accumulated in ignorance of possible
> u64_stats_fetch_retry() events. These statistics are already accumulated
> by u64_stats_inc(). Fix this by reading them into temporary variables
> first.
>
> Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets")
> Signed-off-by: David Yang <mmyangfl@gmail.com>
> ---
>  net/openvswitch/vport.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
> index 6bbbc16ab778..bc46d661b527 100644
> --- a/net/openvswitch/vport.c
> +++ b/net/openvswitch/vport.c
> @@ -319,13 +319,17 @@ int ovs_vport_get_upcall_stats(struct vport *vport, struct sk_buff *skb)
>         for_each_possible_cpu(i) {
>                 const struct vport_upcall_stats_percpu *stats;
>                 unsigned int start;
> +               __u64 n_success;
> +               __u64 n_fail;

Please use u64

New __u64 only makes sense in include/uapi/

Feel free to change existing variables for consistency in your V2
patch (please wait ~24 hours before sending it)

diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index 6bbbc16ab7780840c0f0d18f629b4747efe8f0e4..1c51f1fe0810976bbeece229be4370cad9a31c1c
100644
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c
@@ -310,12 +310,10 @@ void ovs_vport_get_stats(struct vport *vport,
struct ovs_vport_stats *stats)
  */
 int ovs_vport_get_upcall_stats(struct vport *vport, struct sk_buff *skb)
 {
+       u64 tx_success = 0, tx_fail = 0;
        struct nlattr *nla;
        int i;

-       __u64 tx_success = 0;
-       __u64 tx_fail = 0;
-
        for_each_possible_cpu(i) {
                const struct vport_upcall_stats_percpu *stats;
                unsigned int start;