2021-01-11 11:48:12

by Neeraj Upadhyay

Subject: [PATCH] rcu: Only trace when cbs are accelerated

Fix rcu_accelerate_cbs() traces to only trace when cbs are
accelerated in current call.

Signed-off-by: Neeraj Upadhyay <[email protected]>
---
kernel/rcu/tree.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 804e543..338b817 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1508,8 +1508,9 @@ static bool rcu_accelerate_cbs(struct rcu_node *rnp, struct rcu_data *rdp)
* number.
*/
gp_seq_req = rcu_seq_snap(&rcu_state.gp_seq);
- if (rcu_segcblist_accelerate(&rdp->cblist, gp_seq_req))
- ret = rcu_start_this_gp(rnp, rdp, gp_seq_req);
+ if (!rcu_segcblist_accelerate(&rdp->cblist, gp_seq_req))
+ return ret;
+ ret = rcu_start_this_gp(rnp, rdp, gp_seq_req);

/* Trace depending on how much we were able to accelerate. */
if (rcu_segcblist_restempty(&rdp->cblist, RCU_WAIT_TAIL))
--
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2021-01-11 17:37:32

by Steven Rostedt

Subject: Re: [PATCH] rcu: Only trace when cbs are accelerated

On Mon, 11 Jan 2021 17:15:01 +0530
Neeraj Upadhyay <[email protected]> wrote:

> Fix rcu_accelerate_cbs() traces to only trace when cbs are
> accelerated in current call.

The body of the commit should explain "why" not "what". Why not trace the
cbs when not accelerated in the current call?

-- Steve


>
> Signed-off-by: Neeraj Upadhyay <[email protected]>