Expires is modified in different threads (revalidator, pmd-rx, bfd-tx).
It's better to use atomics for such potentially parallel write.
Signed-off-by: Paolo Valerio
---
v2:
- modified commit description
- added _MS suffix to NEIGH_ENTRY_DEFAULT_IDLE_TIME
- renamed local variable expired -> expires
- turned relaxed load/store to acq/rel
---
lib/tnl-neigh-cache.c | 32 +++-
1 file changed, 23 insertions(+), 9 deletions(-)
diff --git a/lib/tnl-neigh-cache.c b/lib/tnl-neigh-cache.c
index 5bda4af7e..1e6cc31db 100644
--- a/lib/tnl-neigh-cache.c
+++ b/lib/tnl-neigh-cache.c
@@ -32,6 +32,7 @@
#include "errno.h"
#include "flow.h"
#include "netdev.h"
+#include "ovs-atomic.h"
#include "ovs-thread.h"
#include "packets.h"
#include "openvswitch/poll-loop.h"
@@ -44,14 +45,13 @@
#include "openvswitch/vlog.h"
-/* In seconds */
-#define NEIGH_ENTRY_DEFAULT_IDLE_TIME (15 * 60)
+#define NEIGH_ENTRY_DEFAULT_IDLE_TIME_MS (15 * 60 * 1000)
struct tnl_neigh_entry {
struct cmap_node cmap_node;
struct in6_addr ip;
struct eth_addr mac;
-time_t expires; /* Expiration time. */
+atomic_llong expires; /* Expiration time in ms. */
char br_name[IFNAMSIZ];
};
@@ -64,6 +64,16 @@ tnl_neigh_hash(const struct in6_addr *ip)
return hash_bytes(ip->s6_addr, 16, 0);
}
+static bool
+tnl_neigh_expired(struct tnl_neigh_entry *neigh)
+{
+long long expires;
+
+atomic_read_explicit(&neigh->expires, &expires, memory_order_acquire);
+
+return expires <= time_msec();
+}
+
static struct tnl_neigh_entry *
tnl_neigh_lookup__(const char br_name[IFNAMSIZ], const struct in6_addr *dst)
{
@@ -73,11 +83,13 @@ tnl_neigh_lookup__(const char br_name[IFNAMSIZ], const
struct in6_addr *dst)
hash = tnl_neigh_hash(dst);
CMAP_FOR_EACH_WITH_HASH (neigh, cmap_node, hash, &table) {
if (ipv6_addr_equals(&neigh->ip, dst) && !strcmp(neigh->br_name,
br_name)) {
-if (neigh->expires <= time_now()) {
+if (tnl_neigh_expired(neigh)) {
return NULL;
}
-neigh->expires = time_now() + NEIGH_ENTRY_DEFAULT_IDLE_TIME;
+atomic_store_explicit(&neigh->expires, time_msec() +
+ NEIGH_ENTRY_DEFAULT_IDLE_TIME_MS,
+ memory_order_release);
return neigh;
}
}
@@ -121,7 +133,8 @@ tnl_neigh_set__(const char name[IFNAMSIZ], const struct
in6_addr *dst,
struct tnl_neigh_entry *neigh = tnl_neigh_lookup__(name, dst);
if (neigh) {
if (eth_addr_equals(neigh->mac, mac)) {
-neigh->expires = time_now() + NEIGH_ENTRY_DEFAULT_IDLE_TIME;
+atomic_store_relaxed(&neigh->expires, time_msec() +
+ NEIGH_ENTRY_DEFAULT_IDLE_TIME_MS);
ovs_mutex_unlock(&mutex);
return;
}
@@ -133,7 +146,8 @@ tnl_neigh_set__(const char name[IFNAMSIZ], const struct
in6_addr *dst,
neigh->ip = *dst;
neigh->mac = mac;
-neigh->expires = time_now() + NEIGH_ENTRY_DEFAULT_IDLE_TIME;
+atomic_store_relaxed(&neigh->expires, time_msec() +
+ NEIGH_ENTRY_DEFAULT_IDLE_TIME_MS);
ovs_strlcpy(neigh->br_name, name, sizeof neigh->br_name);
cmap_insert(&table, &neigh->cmap_node, tnl_neigh_hash(&neigh->ip));
ovs_mutex_unlock(&mutex);
@@ -208,7 +222,7 @@ tnl_neigh_cache_run(void)
ovs_mutex_lock(&mutex);
CMAP_FOR_EACH(neigh, cmap_node, &table) {
-if (neigh->expires <= time_now()) {
+if (tnl_neigh_expired(neigh)) {
tnl_neigh_delete(neigh);
changed = true;
}
@@ -319,7 +333,7 @@ tnl_neigh_cache_show(struct unixctl_conn *conn, int argc
OVS_UNUSED,
ds_put_format(&ds, ETH_ADDR_FMT" %s",
ETH_ADDR_ARGS(neigh->mac), neigh->br_name);
-if (neigh->expires <= time_now()) {
+if (tnl_neigh_expired(neigh)) {
ds_put_format(&ds, " STALE");
}
ds_put_char(&ds, '\n');
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