From: Peter Zijlstra <peterz@infradead.org>
To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
rostedt@goodmis.org
Cc: peterz@infradead.org, mingo@kernel.org, joel@joelfernandes.org,
gregkh@linuxfoundation.org, gustavo@embeddedor.com,
tglx@linutronix.de, paulmck@kernel.org, josh@joshtriplett.org,
mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com
Subject: [PATCH 7/8] tracing: Employ trace_rcu_{enter,exit}()
Date: Wed, 12 Feb 2020 10:32:17 +0100 [thread overview]
Message-ID: <20200212094108.007700525@infradead.org> (raw)
In-Reply-To: 20200212093210.468391728@infradead.org
Replace the opencoded (and incomplete) RCU manipulations with the new
helpers to ensure a regular RCU context when calling into
__ftrace_trace_stack().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
kernel/trace/trace.c | 19 +++----------------
1 file changed, 3 insertions(+), 16 deletions(-)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2989,24 +2989,11 @@ void __trace_stack(struct trace_array *t
int pc)
{
struct trace_buffer *buffer = tr->array_buffer.buffer;
+ unsigned long rcu_flags;
- if (rcu_is_watching()) {
- __ftrace_trace_stack(buffer, flags, skip, pc, NULL);
- return;
- }
-
- /*
- * When an NMI triggers, RCU is enabled via rcu_nmi_enter(),
- * but if the above rcu_is_watching() failed, then the NMI
- * triggered someplace critical, and rcu_irq_enter() should
- * not be called from NMI.
- */
- if (unlikely(in_nmi()))
- return;
-
- rcu_irq_enter_irqsave();
+ rcu_flags = trace_rcu_enter();
__ftrace_trace_stack(buffer, flags, skip, pc, NULL);
- rcu_irq_exit_irqsave();
+ trace_rcu_exit(rcu_flags);
}
/**
next prev parent reply other threads:[~2020-02-12 9:43 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-12 9:32 [PATCH 0/8] tracing vs rcu vs nmi Peter Zijlstra
2020-02-12 9:32 ` [PATCH 1/8] rcu: Rename rcu_irq_{enter,exit}_irqson() Peter Zijlstra
2020-02-12 9:32 ` [PATCH 2/8] rcu: Mark rcu_dynticks_curr_cpu_in_eqs() inline Peter Zijlstra
2020-02-12 9:32 ` [PATCH 3/8] rcu,tracing: Create trace_rcu_{enter,exit}() Peter Zijlstra
2020-02-12 9:32 ` [PATCH 4/8] sched,rcu,tracing: Mark preempt_count_{add,sub}() notrace Peter Zijlstra
2020-02-12 14:24 ` Steven Rostedt
2020-02-12 15:02 ` Peter Zijlstra
2020-02-12 15:14 ` Steven Rostedt
2020-02-12 15:38 ` Peter Zijlstra
2020-02-12 9:32 ` [PATCH 5/8] x86,tracing: Mark debug_stack_{set_zero,reset)() notrace Peter Zijlstra
2020-02-12 14:25 ` Steven Rostedt
2020-02-12 15:04 ` Peter Zijlstra
2020-02-12 15:18 ` Steven Rostedt
2020-02-12 15:39 ` Peter Zijlstra
2020-02-12 9:32 ` [PATCH 6/8] perf,tracing: Prepare the perf-trace interface for RCU changes Peter Zijlstra
2020-02-12 14:26 ` Steven Rostedt
2020-02-12 15:07 ` Mathieu Desnoyers
2020-02-12 9:32 ` Peter Zijlstra [this message]
2020-02-12 9:32 ` [PATCH 8/8] tracing: Remove regular RCU context for _rcuidle tracepoints (again) Peter Zijlstra
2020-02-12 14:29 ` Steven Rostedt
2020-02-12 15:12 ` Peter Zijlstra
2020-02-12 10:01 ` [PATCH 0/8] tracing vs rcu vs nmi Peter Zijlstra
2020-02-12 10:56 ` Will Deacon
2020-02-12 11:58 ` Peter Zijlstra
2020-02-12 14:32 ` Steven Rostedt
2020-02-12 15:21 ` Peter Zijlstra
2020-02-12 10:03 ` Peter Zijlstra
2020-02-12 10:07 ` Peter Zijlstra
2020-02-12 10:09 ` Peter Zijlstra
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