From 3cd9a74bead167bed0d783430e74b6eacff5f773 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 1 Feb 2021 00:05:44 +0100 Subject: [PATCH] rcu: Pull deferred rcuog wake up to rcu_eqs_enter() callers commit 54b7429efffc99e845ba9381bee3244f012a06c2 upstream. Deferred wakeup of rcuog kthreads upon RCU idle mode entry is going to be handled differently whether initiated by idle, user or guest. Prepare with pulling that control up to rcu_eqs_enter() callers. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20210131230548.32970-2-frederic@kernel.org Signed-off-by: Greg Kroah-Hartman --- kernel/rcu/tree.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 1b1d2b09efa9..3dc02ee17957 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -579,7 +579,6 @@ static void rcu_eqs_enter(bool user) trace_rcu_dyntick(TPS("Start"), rdp->dynticks_nesting, 0, atomic_read(&rdp->dynticks)); WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current)); rdp = this_cpu_ptr(&rcu_data); - do_nocb_deferred_wakeup(rdp); rcu_prepare_for_idle(); rcu_preempt_deferred_qs(current); WRITE_ONCE(rdp->dynticks_nesting, 0); /* Avoid irq-access tearing. */ @@ -600,7 +599,10 @@ static void rcu_eqs_enter(bool user) */ void rcu_idle_enter(void) { + struct rcu_data *rdp = this_cpu_ptr(&rcu_data); + lockdep_assert_irqs_disabled(); + do_nocb_deferred_wakeup(rdp); rcu_eqs_enter(false); } @@ -618,7 +620,14 @@ void rcu_idle_enter(void) */ void rcu_user_enter(void) { + struct rcu_data *rdp = this_cpu_ptr(&rcu_data); + lockdep_assert_irqs_disabled(); + + instrumentation_begin(); + do_nocb_deferred_wakeup(rdp); + instrumentation_end(); + rcu_eqs_enter(true); } #endif /* CONFIG_NO_HZ_FULL */