On 1/21/26 8:29 AM, 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 <[email protected]>
> ---
> v1: https://lore.kernel.org/r/[email protected]
> - use u64 instead of __u64
> net/openvswitch/vport.c | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
> index 6bbbc16ab778..f0ce8ce1dce0 100644
> --- a/net/openvswitch/vport.c
> +++ b/net/openvswitch/vport.c
> @@ -310,22 +310,23 @@ 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;
> + u64 n_success, n_fail;
> unsigned int start;
>
> 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));
Would be good to have an empty line here for readability, but a new version
just for this seems a bit excessive.
Either way:
Acked-by: Ilya Maximets <[email protected]>
> + tx_success += n_success;
> + tx_fail += n_fail;
> }
>
> nla = nla_nest_start_noflag(skb, OVS_VPORT_ATTR_UPCALL_STATS);
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