| Message ID | 20220604143530.65815-3-hepeng.0320@bytedance.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [ovs-dev,ovs-dev,v1,1/4] ofproto-dpif-upcall: fix push_dp_ops | expand |
diff --git a/ofproto/ofproto-dpif-upcall.c b/ofproto/ofproto-dpif-upcall.c index 9c55e43c1..791606cc1 100644 --- a/ofproto/ofproto-dpif-upcall.c +++ b/ofproto/ofproto-dpif-upcall.c @@ -1868,6 +1868,7 @@ try_ukey_replace(struct umap *umap, struct udpif_key *old_ukey, ovs_mutex_lock(&new_ukey->mutex); cmap_replace(&umap->cmap, &old_ukey->cmap_node, &new_ukey->cmap_node, new_ukey->hash); + new_ukey->dump_seq = old_ukey->dump_seq; ovsrcu_postpone(ukey_delete__, old_ukey); transition_ukey(old_ukey, UKEY_DELETED); transition_ukey(new_ukey, UKEY_VISIBLE);
The userspace datapath mananges all the magaflows by a cmap. The cmap data structrue will grow/shrink during the datapath processing and it will re-position megaflows. This might result in two revalidator threads might process a same megaflow during one dump stage. Consider a situation that, revalidator 1 processes a megaflow A, and decides to delete it from the datapath, at the mean time, this megaflow A is also queued in the process batch of revalidator 2. After A is deleted from datapath, revalidator 2 will take the stats info from A and contribute to the OpenFlow rules' stats. Now it's ok for revalidator 2 to process the old megaflow A again, even it's deleted, as the corresponding ukey's state is UKEY_EVICTED, and its dump_seq shows it's already dumped. Assume that right after A is deleted, a PMD thread generates again a new megaflow B which has the same match and action of A. The ukey of megaflow B will replace the one of megaflow A. Now the ukey B is new to the revalidator system. Now since ukey B is newly generated, the revalidator will count the stats info as new, and contribute the old megaflow A's stats again into the OpenFlow rules' stats, this results in an inconsistent stats between ukeys and megaflows. To fix this, the newly generated the ukey B should take the dump_seq of replaced A to avoid a same megaflow being revalidated twice in one dump stage. We observe in the production environment, the OpenFlow rules' stats sometimes are amplified compared to the actual value. Signed-off-by: Peng He <hepeng.0320@bytedance.com> --- ofproto/ofproto-dpif-upcall.c | 1 + 1 file changed, 1 insertion(+)