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authorIdo Schimmel <idosch@nvidia.com>2024-03-06 13:49:17 +0100
committerDavid S. Miller <davem@davemloft.net>2024-03-08 10:35:46 +0000
commitf4676ea74b8549cd88dbfe2a592ce4530039e61f (patch)
tree952b4cb513c2bf7a94f3258e3efb020db76c4789
parenta207eab1039b501daddc8e729c9cc5d99fe93d18 (diff)
net: nexthop: Add nexthop group entry stats
Add nexthop group entry stats to count the number of packets forwarded via each nexthop in the group. The stats will be exposed to user space for better data path observability in the next patch. The per-CPU stats pointer is placed at the beginning of 'struct nh_grp_entry', so that all the fields accessed for the data path reside on the same cache line: struct nh_grp_entry { struct nexthop * nh; /* 0 8 */ struct nh_grp_entry_stats * stats; /* 8 8 */ u8 weight; /* 16 1 */ /* XXX 7 bytes hole, try to pack */ union { struct { atomic_t upper_bound; /* 24 4 */ } hthr; /* 24 4 */ struct { struct list_head uw_nh_entry; /* 24 16 */ u16 count_buckets; /* 40 2 */ u16 wants_buckets; /* 42 2 */ } res; /* 24 24 */ }; /* 24 24 */ struct list_head nh_list; /* 48 16 */ /* --- cacheline 1 boundary (64 bytes) --- */ struct nexthop * nh_parent; /* 64 8 */ /* size: 72, cachelines: 2, members: 6 */ /* sum members: 65, holes: 1, sum holes: 7 */ /* last cacheline: 8 bytes */ }; Co-developed-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/nexthop.h6
-rw-r--r--net/ipv4/nexthop.c35
2 files changed, 37 insertions, 4 deletions
diff --git a/include/net/nexthop.h b/include/net/nexthop.h
index 77e99cba60ad..6e6a36fee51e 100644
--- a/include/net/nexthop.h
+++ b/include/net/nexthop.h
@@ -95,8 +95,14 @@ struct nh_res_table {
struct nh_res_bucket nh_buckets[] __counted_by(num_nh_buckets);
};
+struct nh_grp_entry_stats {
+ u64_stats_t packets;
+ struct u64_stats_sync syncp;
+};
+
struct nh_grp_entry {
struct nexthop *nh;
+ struct nh_grp_entry_stats __percpu *stats;
u8 weight;
union {
diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index 576981f4ca49..92dc21a231f8 100644
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -480,6 +480,7 @@ static void nexthop_free_group(struct nexthop *nh)
struct nh_grp_entry *nhge = &nhg->nh_entries[i];
WARN_ON(!list_empty(&nhge->nh_list));
+ free_percpu(nhge->stats);
nexthop_put(nhge->nh);
}
@@ -660,6 +661,16 @@ nla_put_failure:
return -EMSGSIZE;
}
+static void nh_grp_entry_stats_inc(struct nh_grp_entry *nhge)
+{
+ struct nh_grp_entry_stats *cpu_stats;
+
+ cpu_stats = this_cpu_ptr(nhge->stats);
+ u64_stats_update_begin(&cpu_stats->syncp);
+ u64_stats_inc(&cpu_stats->packets);
+ u64_stats_update_end(&cpu_stats->syncp);
+}
+
static int nla_put_nh_group(struct sk_buff *skb, struct nh_group *nhg)
{
struct nexthop_grp *p;
@@ -1182,6 +1193,7 @@ static struct nexthop *nexthop_select_path_fdb(struct nh_group *nhg, int hash)
if (hash > atomic_read(&nhge->hthr.upper_bound))
continue;
+ nh_grp_entry_stats_inc(nhge);
return nhge->nh;
}
@@ -1191,7 +1203,7 @@ static struct nexthop *nexthop_select_path_fdb(struct nh_group *nhg, int hash)
static struct nexthop *nexthop_select_path_hthr(struct nh_group *nhg, int hash)
{
- struct nexthop *rc = NULL;
+ struct nh_grp_entry *nhge0 = NULL;
int i;
if (nhg->fdb_nh)
@@ -1206,16 +1218,20 @@ static struct nexthop *nexthop_select_path_hthr(struct nh_group *nhg, int hash)
if (!nexthop_is_good_nh(nhge->nh))
continue;
- if (!rc)
- rc = nhge->nh;
+ if (!nhge0)
+ nhge0 = nhge;
if (hash > atomic_read(&nhge->hthr.upper_bound))
continue;
+ nh_grp_entry_stats_inc(nhge);
return nhge->nh;
}
- return rc ? : nhg->nh_entries[0].nh;
+ if (!nhge0)
+ nhge0 = &nhg->nh_entries[0];
+ nh_grp_entry_stats_inc(nhge0);
+ return nhge0->nh;
}
static struct nexthop *nexthop_select_path_res(struct nh_group *nhg, int hash)
@@ -1231,6 +1247,7 @@ static struct nexthop *nexthop_select_path_res(struct nh_group *nhg, int hash)
bucket = &res_table->nh_buckets[bucket_index];
nh_res_bucket_set_busy(bucket);
nhge = rcu_dereference(bucket->nh_entry);
+ nh_grp_entry_stats_inc(nhge);
return nhge->nh;
}
@@ -1804,6 +1821,7 @@ static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge,
newg->has_v4 = true;
list_del(&nhges[i].nh_list);
+ new_nhges[j].stats = nhges[i].stats;
new_nhges[j].nh_parent = nhges[i].nh_parent;
new_nhges[j].nh = nhges[i].nh;
new_nhges[j].weight = nhges[i].weight;
@@ -1819,6 +1837,7 @@ static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge,
rcu_assign_pointer(nhp->nh_grp, newg);
list_del(&nhge->nh_list);
+ free_percpu(nhge->stats);
nexthop_put(nhge->nh);
/* Removal of a NH from a resilient group is notified through
@@ -2483,6 +2502,13 @@ static struct nexthop *nexthop_create_group(struct net *net,
if (nhi->family == AF_INET)
nhg->has_v4 = true;
+ nhg->nh_entries[i].stats =
+ netdev_alloc_pcpu_stats(struct nh_grp_entry_stats);
+ if (!nhg->nh_entries[i].stats) {
+ err = -ENOMEM;
+ nexthop_put(nhe);
+ goto out_no_nh;
+ }
nhg->nh_entries[i].nh = nhe;
nhg->nh_entries[i].weight = entry[i].weight + 1;
list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list);
@@ -2522,6 +2548,7 @@ static struct nexthop *nexthop_create_group(struct net *net,
out_no_nh:
for (i--; i >= 0; --i) {
list_del(&nhg->nh_entries[i].nh_list);
+ free_percpu(nhg->nh_entries[i].stats);
nexthop_put(nhg->nh_entries[i].nh);
}