On Sat, Sep 17, 2022 at 04:42:00PM +0000, Joel Fernandes (Google) wrote:
> @@ -2809,17 +2825,15 @@ void call_rcu(struct rcu_head *head, rcu_callback_t func)
> }
>
> check_cb_ovld(rdp);
> - if (rcu_nocb_try_bypass(rdp, head, &was_alldone, flags))
> +
> + if (rcu_nocb_try_bypass(rdp, head, &was_alldone, flags)) {
> + __trace_rcu_callback(head, rdp);
> return; // Enqueued onto ->nocb_bypass, so just leave.
> + }
I think the bypass enqueues should be treated differently. Either with extending
the current trace_rcu_callback/trace_rcu_kvfree_callback (might break tools) or
with creating a new trace_rcu_callback_bypass()/trace_rcu_kvfree_callback_bypass().
Those could later be paired with a trace_rcu_bypass_flush().
Thanks.
> +
> // If no-CBs CPU gets here, rcu_nocb_try_bypass() acquired ->nocb_lock.
> rcu_segcblist_enqueue(&rdp->cblist, head);
> - if (__is_kvfree_rcu_offset((unsigned long)func))
> - trace_rcu_kvfree_callback(rcu_state.name, head,
> - (unsigned long)func,
> - rcu_segcblist_n_cbs(&rdp->cblist));
> - else
> - trace_rcu_callback(rcu_state.name, head,
> - rcu_segcblist_n_cbs(&rdp->cblist));
> + __trace_rcu_callback(head, rdp);
>
> trace_rcu_segcb_stats(&rdp->cblist, TPS("SegCBQueued"));
>
> --
> 2.37.3.968.ga6b4b080e4-goog
>
