Commit-ID: 384f77f4cb765707216ea43f9122580d8a07be7d
Gitweb: https://git.kernel.org/tip/384f77f4cb765707216ea43f9122580d8a07be7d
Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
AuthorDate: Thu, 12 Apr 2018 16:16:45 -0700
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
CommitDate: Tue, 15 May 2018 10:30:54 -0700
rcu: The rcu_gp_cleanup() function does not need cpu_needs_another_gp()
All of the cpu_needs_another_gp() function's checks (except for
newly arrived callbacks) have been subsumed into the rcu_gp_cleanup()
function's scan of the rcu_node tree. This commit therefore drops the
call to cpu_needs_another_gp(). The check for newly arrived callbacks
is supplied by rcu_accelerate_cbs(). Any needed advancing (as in the
earlier rcu_advance_cbs() call) will be supplied when the corresponding
CPU becomes aware of the end of the now-completed grace period.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Tested-by: Nicholas Piggin <npiggin@xxxxxxxxx>
---
kernel/rcu/tree.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 07bccb1f0c87..7776d709e060 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2150,11 +2150,9 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
needgp = true;
}
/* Advance CBs to reduce false positives below. */
- needgp = rcu_advance_cbs(rsp, rnp, rdp) || needgp;
- if (needgp || cpu_needs_another_gp(rsp, rdp)) {
+ if (!rcu_accelerate_cbs(rsp, rnp, rdp) && needgp) {
WRITE_ONCE(rsp->gp_flags, RCU_GP_FLAG_INIT);
- trace_rcu_grace_period(rsp->name,
- READ_ONCE(rsp->gpnum),
+ trace_rcu_grace_period(rsp->name, READ_ONCE(rsp->gpnum),
TPS("newreq"));
}
WRITE_ONCE(rsp->gp_flags, rsp->gp_flags & RCU_GP_FLAG_INIT);
--
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