During acceleration of CB, the rsp's gp_seq is rcu_seq_snap'd. This is the value used for acceleration - it is the value of gp_seq at which it is safe the execute all callbacks in the callback list.
The rdp's gp_seq is not very useful for this scenario. Make rcu_grace_period report the rsp's gp_seq instead as it allows one to reason about how the acceleration works. Signed-off-by: Joel Fernandes (Google) <[email protected]> --- kernel/rcu/tree.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 81df1b837dd9d..c3bae7a83d792 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1437,9 +1437,9 @@ static bool rcu_accelerate_cbs(struct rcu_node *rnp, struct rcu_data *rdp) /* Trace depending on how much we were able to accelerate. */ if (rcu_segcblist_restempty(&rdp->cblist, RCU_WAIT_TAIL)) - trace_rcu_grace_period(rcu_state.name, "rdp", rdp->gp_seq, TPS("AccWaitCB")); + trace_rcu_grace_period(rcu_state.name, "rsp", rcu_state.gp_seq, TPS("AccWaitCB")); else - trace_rcu_grace_period(rcu_state.name, "rdp", rdp->gp_seq, TPS("AccReadyCB")); + trace_rcu_grace_period(rcu_state.name, "rsp", rcu_state.gp_seq, TPS("AccReadyCB")); /* Count CBs for tracing. */ rcu_segcblist_countseq(&rdp->cblist, cbs, gps); -- 2.27.0.111.gc72c7da667-goog
