lkml.org 
[lkml]   [2022]   [Sep]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH rcu/next 3/3] rcu: Call trace_rcu_callback() also for bypass queuing (v2)
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
>

\
 
 \ /
  Last update: 2022-09-17 21:58    [W:1.123 / U:2.332 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site