[PATCH net-next v2 4/7] net: openvswitch: fix load tearing with u64_stats
From: David Yang <mmyangfl@gmail.com>
Date: 2026-01-23 16:22:39
Also in:
lkml
Subsystem:
networking [general], openvswitch, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Aaron Conole, Eelco Chaudron, Ilya Maximets, Linus Torvalds
On 64bit arches, struct u64_stats_sync is empty and provides no help against load/store tearing. struct copying should not be considered tear-free. Use u64_stats_reads() instead. Signed-off-by: David Yang <mmyangfl@gmail.com> --- net/openvswitch/datapath.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index d5b6e2002bc1..8ba94df7f942 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c@@ -770,7 +770,8 @@ static void get_dp_stats(const struct datapath *dp, struct ovs_dp_stats *stats, do { start = u64_stats_fetch_begin(&percpu_stats->syncp); - local_stats = *percpu_stats; + u64_stats_reads(&local_stats, percpu_stats, + sizeof(local_stats)); } while (u64_stats_fetch_retry(&percpu_stats->syncp, start)); stats->n_hit += local_stats.n_hit;
--
2.51.0