From: "Paul E. McKenney" <paulmck@kernel.org>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
rostedt@goodmis.org, Neeraj Upadhyay <quic_neeraju@quicinc.com>,
Frederic Weisbecker <frederic@kernel.org>,
"Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH rcu 1/3] rcu/exp: Fix check for idle context in rcu_exp_handler
Date: Fri, 4 Feb 2022 14:55:05 -0800 [thread overview]
Message-ID: <20220204225507.4193113-1-paulmck@kernel.org> (raw)
In-Reply-To: <20220204225409.GA4193020@paulmck-ThinkPad-P17-Gen-1>
From: Neeraj Upadhyay <quic_neeraju@quicinc.com>
For PREEMPT_RCU, the rcu_exp_handler() function checks
whether the current CPU is in idle, by calling
rcu_dynticks_curr_cpu_in_eqs(). However, rcu_exp_handler()
is called in IPI handler context. So, it should be checking
the idle context using rcu_is_cpu_rrupt_from_idle(). Fix this
by using rcu_is_cpu_rrupt_from_idle() instead of
rcu_dynticks_curr_cpu_in_eqs(). Non-preempt configuration
already uses the correct check.
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/rcu/tree_exp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 237a79989abae..1568c8ef185b2 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -656,7 +656,7 @@ static void rcu_exp_handler(void *unused)
*/
if (!depth) {
if (!(preempt_count() & (PREEMPT_MASK | SOFTIRQ_MASK)) ||
- rcu_dynticks_curr_cpu_in_eqs()) {
+ rcu_is_cpu_rrupt_from_idle()) {
rcu_report_exp_rdp(rdp);
} else {
WRITE_ONCE(rdp->cpu_no_qs.b.exp, true);
--
2.31.1.189.g2e36527f23
next prev parent reply other threads:[~2022-02-04 22:55 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-04 22:54 [PATCH rcu 0/3] Expedited-grace-period updates for v5.18 Paul E. McKenney
2022-02-04 22:55 ` Paul E. McKenney [this message]
2022-02-04 22:55 ` [PATCH rcu 2/3] rcu: Mark ->expmask access in synchronize_rcu_expedited_wait() Paul E. McKenney
2022-02-04 22:55 ` [PATCH rcu 3/3] rcu: Allow expedited RCU grace periods on incoming CPUs Paul E. McKenney
2022-02-08 18:56 ` Tejun Heo
2022-02-09 18:23 ` Mukesh Ojha
2022-02-09 22:06 ` Paul E. McKenney
2022-02-11 18:44 ` Mukesh Ojha
2022-02-11 22:14 ` Paul E. McKenney
2022-02-12 8:47 ` Mukesh Ojha
2022-02-12 11:28 ` Neeraj Upadhyay
2022-02-12 13:56 ` Mukesh Ojha
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