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authorFrederic Weisbecker <frederic@kernel.org>2020-11-13 15:13:28 +0300
committerPaul E. McKenney <paulmck@kernel.org>2021-01-07 03:24:59 +0300
commit634954c2dbf88e67aa267798f60af6b9a476cf4b (patch)
treecdb3c46cde9bb47f0787b7158fa46076525f248e /kernel/rcu
parent32aa2f4170d22f0b9fcb75ab05679ab122fae373 (diff)
downloadlinux-634954c2dbf88e67aa267798f60af6b9a476cf4b.tar.xz
rcu/nocb: Locally accelerate callbacks as long as offloading isn't complete
The local callbacks processing checks if any callbacks need acceleration. This commit carries out this checking under nocb lock protection in the middle of toggle operations, during which time rcu_core() executes concurrently with GP/CB kthreads. Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Inspired-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/tree.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index ec14c017c0e3..03810a58fdd0 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2699,7 +2699,6 @@ static __latent_entropy void rcu_core(void)
unsigned long flags;
struct rcu_data *rdp = raw_cpu_ptr(&rcu_data);
struct rcu_node *rnp = rdp->mynode;
- const bool offloaded = rcu_segcblist_is_offloaded(&rdp->cblist);
const bool do_batch = !rcu_segcblist_completely_offloaded(&rdp->cblist);
if (cpu_is_offline(smp_processor_id()))
@@ -2720,11 +2719,11 @@ static __latent_entropy void rcu_core(void)
/* No grace period and unregistered callbacks? */
if (!rcu_gp_in_progress() &&
- rcu_segcblist_is_enabled(&rdp->cblist) && !offloaded) {
- local_irq_save(flags);
+ rcu_segcblist_is_enabled(&rdp->cblist) && do_batch) {
+ rcu_nocb_lock_irqsave(rdp, flags);
if (!rcu_segcblist_restempty(&rdp->cblist, RCU_NEXT_READY_TAIL))
rcu_accelerate_cbs_unlocked(rnp, rdp);
- local_irq_restore(flags);
+ rcu_nocb_unlock_irqrestore(rdp, flags);
}
rcu_check_gp_start_stall(rnp, rdp, rcu_jiffies_till_stall_check());