From: Frederic Weisbecker <frederic@kernel.org>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
"Paul E . McKenney" <paulmck@kernel.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Neeraj Upadhyay <neeraju@codeaurora.org>,
Joel Fernandes <joel@joelfernandes.org>,
Josh Triplett <josh@joshtriplett.org>
Subject: [PATCH 12/16] rcu/nocb: Only cond_resched() from actual offloaded batch processing
Date: Fri, 23 Oct 2020 16:46:45 +0200 [thread overview]
Message-ID: <20201023144649.53046-13-frederic@kernel.org> (raw)
In-Reply-To: <20201023144649.53046-1-frederic@kernel.org>
rcu_do_batch() will be callable concurrently by softirqs and offloaded
processing. So make sure we actually call cond resched only from the
offloaded context.
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
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>
---
kernel/rcu/tree.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 6bad7018dc18..35834ce2d042 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2491,8 +2491,7 @@ static void rcu_do_batch(struct rcu_data *rdp)
/* Exceeded the time limit, so leave. */
break;
}
- if (offloaded) {
- WARN_ON_ONCE(in_serving_softirq());
+ if (!in_serving_softirq()) {
local_bh_enable();
lockdep_assert_irqs_enabled();
cond_resched_tasks_rcu_qs();
--
2.25.1
next prev parent reply other threads:[~2020-10-23 14:47 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-23 14:46 [PATCH 00/16] rcu/nocb: De-offload and re-offload support v3 Frederic Weisbecker
2020-10-23 14:46 ` [PATCH 01/16] rcu: Implement rcu_segcblist_is_offloaded() config dependent Frederic Weisbecker
2020-10-23 14:46 ` [PATCH 02/16] rcu: Turn enabled/offload states into a common flag Frederic Weisbecker
2020-10-23 14:46 ` [PATCH 03/16] rcu: Provide basic callback offloading state machine bits Frederic Weisbecker
2020-10-23 14:46 ` [PATCH 04/16] rcu/nocb: Always init segcblist on CPU up Frederic Weisbecker
2020-10-23 14:46 ` [PATCH 05/16] rcu: De-offloading CB kthread Frederic Weisbecker
2020-11-02 13:38 ` Boqun Feng
2020-11-04 14:31 ` Frederic Weisbecker
2020-11-04 14:42 ` Boqun Feng
2020-11-04 14:45 ` Frederic Weisbecker
2020-10-23 14:46 ` [PATCH 06/16] rcu/nocb: Don't deoffload an offline CPU with pending work Frederic Weisbecker
2020-10-23 14:46 ` [PATCH 07/16] rcu: De-offloading GP kthread Frederic Weisbecker
2020-10-23 14:46 ` [PATCH 08/16] rcu: Re-offload support Frederic Weisbecker
2020-10-23 14:46 ` [PATCH 09/16] rcu: Shutdown nocb timer on de-offloading Frederic Weisbecker
2020-10-23 14:46 ` [PATCH 10/16] rcu: Flush bypass before setting SEGCBLIST_SOFTIRQ_ONLY Frederic Weisbecker
2020-10-23 14:46 ` [PATCH 11/16] rcu: Set SEGCBLIST_SOFTIRQ_ONLY at the very last stage of de-offloading Frederic Weisbecker
2020-10-23 14:46 ` Frederic Weisbecker [this message]
2020-10-23 14:46 ` [PATCH 13/16] rcu: Process batch locally as long as offloading isn't complete Frederic Weisbecker
2020-10-23 14:46 ` [PATCH 14/16] rcu: Locally accelerate callbacks " Frederic Weisbecker
2020-10-23 14:46 ` [PATCH 15/16] rcutorture: Test runtime toggling of CPUs' callback offloading Frederic Weisbecker
2020-10-23 14:46 ` [PATCH 16/16] tools/rcutorture: Support nocb toggle in TREE01 Frederic Weisbecker
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