Hi Jacob, I've had a look at the change, and I think mechanically, it gets the job done. The big thing this patch changes is that we dereference the dp group before attempting to allocate a new one. I think there are a few aspects of the patch that could be improved though. See below for my inline comments.
On Mon, Feb 9, 2026 at 11:23 AM Jacob Tanenbaum <[email protected]> wrote: > > If ovn_dp_groups ref_count is decremented when fetching old lflows > during a recalculation we can successfully determine if we can reuse the > flow or not. > > Reported-by: Mark Michelson <[email protected]> > Reported-at: https://issues.redhat.com/browse/FDP-2747 > Signed-off-by: Jacob Tanenbaum <[email protected]> > > diff --git a/northd/lflow-mgr.c b/northd/lflow-mgr.c > index f21024903..19c939cc1 100644 > --- a/northd/lflow-mgr.c > +++ b/northd/lflow-mgr.c > @@ -1053,6 +1053,14 @@ do_ovn_lflow_add(struct lflow_table *lflow_table, > size_t dp_bitmap_len, > if (old_lflow) { > dynamic_bitmap_realloc(&old_lflow->dpg_bitmap, dp_bitmap_len); > if (old_lflow->sync_state != LFLOW_STALE) { > + > + struct hmap *dp_groups; > + enum ovn_datapath_type dp_type = > + ovn_stage_to_datapath_type(old_lflow->stage); > + dp_groups = &lflow_table->dp_groups[dp_type]; > + ovn_dp_group_release(dp_groups, old_lflow->dpg); > + old_lflow->dpg = NULL; The above only needs to be done if old_lflow->dpg is non-NULL. It may be that old_lflow only applied to a single datapath, in which case old_lflow->dp would be non-NULL and old_lflow->dpg would be NULL. > + > return old_lflow; > } > sbuuid = old_lflow->sb_uuid; > @@ -1242,7 +1250,6 @@ sync_lflow_to_sb(struct ovn_lflow *lflow, > > if (pre_sync_dpg != lflow->dpg) { > ovn_dp_group_use(lflow->dpg); > - ovn_dp_group_release(dp_groups, pre_sync_dpg); > } It's hard to comment on this particular change in-line, but I'll do my best :) With the way the code used to work, the lflow->dpg may be one value at the beginning of the sync and then may change to a different value after syncing. This if statement ensured that if the lflow->dpg changed as a result of syncing, then we'd release the old dpg and use the new dpg. With the change you made in do_ovn_lflow_add(), now lflow->dpg will always be NULL when entering sync_lflow_to_sb(). Therefore, pre_sync_dpg will always be NULL. Since it's always going to be NULL, there's not much point in even having pre_sync_dpg exist any longer. Instead, it may be a good idea at the top of the function to add: ovn_assert(lflow->dpg == NULL); We can then also move the ovn_dp_group_use(lflow->dpg) call to just after lflow->dpg is assigned. It's not in this diff, but above this section, there is a call to sbrec_logical_flow_set_logical_dp_group(). You can add the ovn_dp_group_use(lflow->dpg) call just above that line. That way it's more clearly tied to its assignment. > > lflow->sync_state = LFLOW_SYNCED; > -- > 2.52.0 > _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
