bucket update in the cmap lib is protected by a counter. But hash setting is possible to be moved before counter update. This patch fix this issue.
Reviewed-by: Ola Liljedahl <[email protected]> Reviewed-by: Gavin Hu <[email protected]> Signed-off-by: Yanqin Wei <[email protected]> --- lib/cmap.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/lib/cmap.c b/lib/cmap.c index c9eef3f4a..e41c40794 100644 --- a/lib/cmap.c +++ b/lib/cmap.c @@ -598,7 +598,9 @@ cmap_set_bucket(struct cmap_bucket *b, int i, uint32_t c; atomic_read_explicit(&b->counter, &c, memory_order_acquire); - atomic_store_explicit(&b->counter, c + 1, memory_order_release); + atomic_store_explicit(&b->counter, c + 1, memory_order_relaxed); + /*need to make sure setting hash is not moved up before counter update*/ + atomic_thread_fence(memory_order_release); ovsrcu_set(&b->nodes[i].next, node); /* Also atomic. */ b->hashes[i] = hash; atomic_store_explicit(&b->counter, c + 2, memory_order_release); -- 2.17.1 _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
