From: "Paul E. McKenney" <paulmck@kernel.org>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
mingo@kernel.org, jiangshanlai@gmail.com,
akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org,
"Paul E. McKenney" <paulmck@kernel.org>,
"Toke Høiland-Jørgensen" <toke@redhat.com>,
"Masami Hiramatsu" <mhiramat@kernel.org>
Subject: [PATCH tip/core/rcu 3/4] rcu-tasks: Make ksoftirqd provide RCU Tasks quiescent states
Date: Tue, 11 May 2021 16:09:41 -0700 [thread overview]
Message-ID: <20210511230942.2894861-3-paulmck@kernel.org> (raw)
In-Reply-To: <20210511230720.GA2894512@paulmck-ThinkPad-P17-Gen-1>
Heavy networking load can cause a CPU to execute continuously and
indefinitely within ksoftirqd, in which case there will be no voluntary
task switches and thus no RCU-tasks quiescent states. This commit
therefore causes the exiting rcu_softirq_qs() to provide an RCU-tasks
quiescent state.
This of course means that __do_softirq() and its callers cannot be
invoked from within a tracing trampoline.
Reported-by: Toke Høiland-Jørgensen <toke@redhat.com>
Tested-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
---
kernel/rcu/tree.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 8e78b2430c16..f4daa4e60b14 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -242,6 +242,7 @@ void rcu_softirq_qs(void)
{
rcu_qs();
rcu_preempt_deferred_qs(current);
+ rcu_tasks_qs(current, false);
}
/*
--
2.31.1.189.g2e36527f23
next prev parent reply other threads:[~2021-05-11 23:09 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-11 23:07 [PATCH tip/core/rcu 0/6] SRCU updates for v5.14 Paul E. McKenney
2021-05-11 23:07 ` [PATCH tip/core/rcu 1/6] srcu: Remove superfluous sdp->srcu_lock_count zero filling Paul E. McKenney
2021-05-11 23:07 ` [PATCH tip/core/rcu 2/6] srcu: Remove superfluous ssp initialization for early callbacks Paul E. McKenney
2021-05-11 23:07 ` [PATCH tip/core/rcu 3/6] srcu: Unconditionally embed struct lockdep_map Paul E. McKenney
2021-05-11 23:07 ` [PATCH tip/core/rcu 4/6] srcu: Initialize SRCU after timers Paul E. McKenney
2021-05-11 23:07 ` [PATCH tip/core/rcu 5/6] srcu: Fix broken node geometry after early ssp init Paul E. McKenney
2021-05-11 23:07 ` [PATCH tip/core/rcu 6/6] srcu: Early test SRCU polling start Paul E. McKenney
2021-05-11 23:09 ` [PATCH tip/core/rcu 1/4] rcu-tasks: Add block comment laying out RCU Tasks design Paul E. McKenney
2021-05-11 23:09 ` [PATCH tip/core/rcu 2/4] rcu-tasks: Add block comment laying out RCU Rude design Paul E. McKenney
2021-05-11 23:09 ` Paul E. McKenney [this message]
2021-05-11 23:09 ` [PATCH tip/core/rcu 4/4] tasks-rcu: Make show_rcu_tasks_gp_kthreads() be static inline Paul E. McKenney
2021-05-12 18:27 [PATCH tip/core/rcu 3/4] rcu-tasks: Make ksoftirqd provide RCU Tasks quiescent states Paul E. McKenney
2021-05-13 6:54 ` Masami Hiramatsu
2021-05-13 14:21 ` Paul E. McKenney
2021-05-13 17:49 ` Masami Hiramatsu
2021-05-13 19:15 ` Paul E. McKenney
2021-05-14 6:04 ` Masami Hiramatsu
2021-05-17 18:24 ` Paul E. McKenney
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