If the last ovn-controller main loop run started a transaction to the Southbound DB and the transaction is still in progress, ovn-controller will not call engine_run(). In case there were changes to the DB, engine_need_run() would return true which would trigger an immediate forced recompute in the next processing loop iteration.
However, there are scenarios when updates can be processed incrementally even if no Southbound DB transaction is available. One example, often seen in the field, is when the MAC_Binding table is updated. Currently such an update received while a transaction is still committing would trigger a forced recompute. To minimize the number of forced recomputes, we now call engine_run(false), i.e., try to process updates incrementally without allowing recompute, also when ovnsb_idl_txn == NULL. This is safe because ovnsb_idl_txn is not used by change_handlers and run handlers are not allowed to execute when calling engine_run(false). To make sure that other users of ovnsb_idl_txn, like pinctrl_run(), get a chance to run as soon as the transaction is completed, if the engine has successfully run and ovnsb_idl_txn is NULL we trigger an immediate wake and a new iteration of the processing loop. CC: Han Zhou <[email protected]> CC: Numan Siddique <[email protected]> Signed-off-by: Dumitru Ceara <[email protected]> --- controller/ovn-controller.c | 13 +++++++++++++ lib/inc-proc-eng.h | 8 +++++++- 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/controller/ovn-controller.c b/controller/ovn-controller.c index 5874776..4a27d5f 100644 --- a/controller/ovn-controller.c +++ b/controller/ovn-controller.c @@ -2100,6 +2100,14 @@ main(int argc, char *argv[]) } else { engine_run(true); } + } else { + /* Even if there's no SB DB transaction available, + * try to run the engine so that we can handle any + * incremental changes that don't require a recompute. + * If a recompute is required, the engine will abort, + * triggerring a full run in the next iteration. + */ + engine_run(false); } stopwatch_stop(CONTROLLER_LOOP_STOPWATCH_NAME, time_msec()); @@ -2168,6 +2176,11 @@ main(int argc, char *argv[]) "br_int %p, chassis %p", br_int, chassis); engine_set_force_recompute(true); poll_immediate_wake(); + } else if (!ovnsb_idl_txn) { + VLOG_DBG("engine ran, no SB DB transaction available, " + "trigger an immediate loop run: " + "br_int %p, chassis %p", br_int, chassis); + poll_immediate_wake(); } else { engine_set_force_recompute(false); } diff --git a/lib/inc-proc-eng.h b/lib/inc-proc-eng.h index 5b92971..2f90b0a 100644 --- a/lib/inc-proc-eng.h +++ b/lib/inc-proc-eng.h @@ -189,7 +189,13 @@ void engine_add_input(struct engine_node *node, struct engine_node *input, * iteration, and the change can't be tracked across iterations */ void engine_set_force_recompute(bool val); -const struct engine_context * engine_get_context(void); +/* Return the current engine_context. The values in the context can be NULL + * if the engine is run with allow_recompute == false in the current + * iteration. + * Therefore, it is the responsibility of the caller to check the context + * values when called from change_handlers. + */ +const struct engine_context *engine_get_context(void); void engine_set_context(const struct engine_context *); -- 1.8.3.1 _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
