Messages in this thread | | | From | Eelco Chaudron <> | Subject | Re: [ovs-dev] [PATCH] [PATCH 1/2] openvswitch: Add support to count upall packets | Date | Mon, 19 Sep 2022 12:18:10 +0200 |
| |
On 14 Sep 2022, at 14:14, wangchuanlei wrote:
> Add support to count upcall packets on every interface. > I always encounter high cpu use of ovs-vswictchd, this > help to check which interface send too many packets > without open vlog/set switch, and have no influence > on datapath.
Hi,
I did not do a full review, but I think we should not try to make the same mistake as before and embed a structure inside a netlink message.
You are adding “struct ovs_vport_upcall_stats” but in theory, you could have just added the new entry to “ovs_vport_stats”. But this is breaking userspace as it expects an exact structure size :(
So I think the right approach would be to have “OVS_VPORT_ATTR_UPCALL_STATS” be an NLA_NESTED type, and have individual stat attributes as NLA_U64 (or whatever type you need).
What is also confusing is that you use upcall_packets in ovs_vport_upcall_stats, which to me are the total of up calls, but you called it n_missed in your stats. I think you should try to avoid missed in the upcall path, and just call it n_upcall_packets also.
In addition, I think you should keep two types of statics, and make them available, namely the total number of upcalls and the total of upcall failures.
Cheers,
Eelco
> Signed-off-by: wangchuanlei <wangchuanlei@inspur.com> > --- > include/uapi/linux/openvswitch.h | 5 ++++ > net/openvswitch/datapath.c | 45 ++++++++++++++++++++++++++++++++ > net/openvswitch/datapath.h | 10 +++++++ > net/openvswitch/vport.c | 31 ++++++++++++++++++++++ > net/openvswitch/vport.h | 4 +++ > 5 files changed, 95 insertions(+) > > diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h > index 94066f87e9ee..8ec45511bc41 100644 > --- a/include/uapi/linux/openvswitch.h > +++ b/include/uapi/linux/openvswitch.h > @@ -126,6 +126,10 @@ struct ovs_vport_stats { > __u64 tx_dropped; /* no space available in linux */ > }; > > +struct ovs_vport_upcall_stats { > + __u64 upcall_packets; /* total packets upcalls */ > +}; > + > /* Allow last Netlink attribute to be unaligned */ > #define OVS_DP_F_UNALIGNED (1 << 0) > > @@ -277,6 +281,7 @@ enum ovs_vport_attr { > OVS_VPORT_ATTR_PAD, > OVS_VPORT_ATTR_IFINDEX, > OVS_VPORT_ATTR_NETNSID, > + OVS_VPORT_ATTR_UPCALL_STATS, /* struct ovs_vport_upcall_stats */ > __OVS_VPORT_ATTR_MAX > }; > > diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c > index c8a9075ddd0a..f4e1f67dc57a 100644 > --- a/net/openvswitch/datapath.c > +++ b/net/openvswitch/datapath.c > @@ -209,6 +209,23 @@ static struct vport *new_vport(const struct vport_parms *parms) > return vport; > } > > +static void ovs_vport_upcalls(struct sk_buff *skb, > + const struct dp_upcall_info *upcall_info) > +{ > + if (upcall_info->cmd == OVS_PACKET_CMD_MISS || > + upcall_info->cmd == OVS_PACKET_CMD_ACTION) { > + const struct vport *p = OVS_CB(skb)->input_vport; > + struct vport_upcall_stats_percpu *vport_stats; > + u64 *stats_counter_upcall; > + > + vport_stats = this_cpu_ptr(p->vport_upcall_stats_percpu); > + stats_counter_upcall = &vport_stats->n_missed; > + u64_stats_update_begin(&vport_stats->syncp); > + (*stats_counter_upcall)++; > + u64_stats_update_end(&vport_stats->syncp); > + } > +} > + > void ovs_dp_detach_port(struct vport *p) > { > ASSERT_OVSL(); > @@ -216,6 +233,9 @@ void ovs_dp_detach_port(struct vport *p) > /* First drop references to device. */ > hlist_del_rcu(&p->dp_hash_node); > > + /* Free percpu memory */ > + free_percpu(p->vport_upcall_stats_percpu); > + > /* Then destroy it. */ > ovs_vport_del(p); > } > @@ -308,6 +328,8 @@ int ovs_dp_upcall(struct datapath *dp, struct sk_buff *skb, > if (err) > goto err; > > + ovs_vport_upcalls(skb, upcall_info); > + > return 0; > > err: > @@ -1825,6 +1847,13 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info) > goto err_destroy_portids; > } > > + vport->vport_upcall_stats_percpu = > + netdev_alloc_pcpu_stats(struct vport_upcall_stats_percpu); > + if (!vport->vport_upcall_stats_percpu) { > + err = -ENOMEM; > + goto err_destroy_portids; > + } > + > err = ovs_dp_cmd_fill_info(dp, reply, info->snd_portid, > info->snd_seq, 0, OVS_DP_CMD_NEW); > BUG_ON(err < 0); > @@ -2068,6 +2097,7 @@ static int ovs_vport_cmd_fill_info(struct vport *vport, struct sk_buff *skb, > { > struct ovs_header *ovs_header; > struct ovs_vport_stats vport_stats; > + struct ovs_vport_upcall_stats vport_upcall_stats; > int err; > > ovs_header = genlmsg_put(skb, portid, seq, &dp_vport_genl_family, > @@ -2097,6 +2127,13 @@ static int ovs_vport_cmd_fill_info(struct vport *vport, struct sk_buff *skb, > OVS_VPORT_ATTR_PAD)) > goto nla_put_failure; > > + ovs_vport_get_upcall_stats(vport, &vport_upcall_stats); > + if (nla_put_64bit(skb, OVS_VPORT_ATTR_UPCALL_STATS, > + sizeof(struct ovs_vport_upcall_stats), > + &vport_upcall_stats, > + OVS_VPORT_ATTR_PAD)) > + goto nla_put_failure; > + > if (ovs_vport_get_upcall_portids(vport, skb)) > goto nla_put_failure; > > @@ -2278,6 +2315,14 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info) > goto exit_unlock_free; > } > > + vport->vport_upcall_stats_percpu = > + netdev_alloc_pcpu_stats(struct vport_upcall_stats_percpu); > + > + if (!vport->vport_upcall_stats_percpu) { > + err = -ENOMEM; > + goto exit_unlock_free; > + } > + > err = ovs_vport_cmd_fill_info(vport, reply, genl_info_net(info), > info->snd_portid, info->snd_seq, 0, > OVS_VPORT_CMD_NEW, GFP_KERNEL); > diff --git a/net/openvswitch/datapath.h b/net/openvswitch/datapath.h > index 0cd29971a907..57fc002142a3 100644 > --- a/net/openvswitch/datapath.h > +++ b/net/openvswitch/datapath.h > @@ -50,6 +50,16 @@ struct dp_stats_percpu { > struct u64_stats_sync syncp; > }; > > +/** > + * struct vport_upcall_stats_percpu - per-cpu packet upcall statistics for > + * a given vport. > + * @n_missed: Number of packets that upcall to userspace. > + */ > +struct vport_upcall_stats_percpu { > + u64 n_missed; > + struct u64_stats_sync syncp; > +}; > + > /** > * struct dp_nlsk_pids - array of netlink portids of for a datapath. > * This is used when OVS_DP_F_DISPATCH_UPCALL_PER_CPU > diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c > index 82a74f998966..c05056f907f0 100644 > --- a/net/openvswitch/vport.c > +++ b/net/openvswitch/vport.c > @@ -284,6 +284,37 @@ void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats) > stats->tx_packets = dev_stats->tx_packets; > } > > +/** > + * ovs_vport_get_upcall_stats - retrieve upcall stats > + * > + * @vport: vport from which to retrieve the stats > + * @ovs_vport_upcall_stats: location to store stats > + * > + * Retrieves upcall stats for the given device. > + * > + * Must be called with ovs_mutex or rcu_read_lock. > + */ > +void ovs_vport_get_upcall_stats(struct vport *vport, struct ovs_vport_upcall_stats *stats) > +{ > + int i; > + > + stats->upcall_packets = 0; > + > + for_each_possible_cpu(i) { > + const struct vport_upcall_stats_percpu *percpu_upcall_stats; > + struct vport_upcall_stats_percpu local_stats; > + unsigned int start; > + > + percpu_upcall_stats = per_cpu_ptr(vport->vport_upcall_stats_percpu, i); > + do { > + start = u64_stats_fetch_begin_irq(&percpu_upcall_stats->syncp); > + local_stats = *percpu_upcall_stats; > + } while (u64_stats_fetch_retry_irq(&percpu_upcall_stats->syncp, start)); > + > + stats->upcall_packets += local_stats.n_missed; > + } > +} > + > /** > * ovs_vport_get_options - retrieve device options > * > diff --git a/net/openvswitch/vport.h b/net/openvswitch/vport.h > index 7d276f60c000..6defacd6d718 100644 > --- a/net/openvswitch/vport.h > +++ b/net/openvswitch/vport.h > @@ -32,6 +32,9 @@ struct vport *ovs_vport_locate(const struct net *net, const char *name); > > void ovs_vport_get_stats(struct vport *, struct ovs_vport_stats *); > > +void ovs_vport_get_upcall_stats(struct vport *vport, > + struct ovs_vport_upcall_stats *stats); > + > int ovs_vport_set_options(struct vport *, struct nlattr *options); > int ovs_vport_get_options(const struct vport *, struct sk_buff *); > > @@ -78,6 +81,7 @@ struct vport { > struct hlist_node hash_node; > struct hlist_node dp_hash_node; > const struct vport_ops *ops; > + struct vport_upcall_stats_percpu __percpu *vport_upcall_stats_percpu; > > struct list_head detach_list; > struct rcu_head rcu; > -- > 2.27.0 > > _______________________________________________ > dev mailing list > dev@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev
| |