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Date:   Tue, 11 Feb 2020 14:10:46 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     "Paul E. McKenney" <paulmck@kernel.org>
Cc:     Steven Rostedt <rostedt@goodmis.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@kernel.org>,
        "Joel Fernandes (Google)" <joel@joelfernandes.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Gustavo A. R. Silva" <gustavo@embeddedor.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Josh Triplett <josh@joshtriplett.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Lai Jiangshan <jiangshanlai@gmail.com>
Subject: Re: [PATCH] tracing/perf: Move rcu_irq_enter/exit_irqson() to perf
 trace point hook
Message-ID: <20200211131046.GR14914@hirez.programming.kicks-ass.net>
References: <20200210170643.3544795d@gandalf.local.home>
 <20200211114954.GK14914@hirez.programming.kicks-ass.net>
 <20200211125929.GG2935@paulmck-ThinkPad-P72>
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On Tue, Feb 11, 2020 at 04:59:29AM -0800, Paul E. McKenney wrote:

> However, a quick grep for NMI_MASK didn't show me the NMI_MASK bit
> getting set.  Help?

| #define nmi_enter()						\
| 	do {							\
| 		arch_nmi_enter();				\
| 		printk_nmi_enter();				\
| 		lockdep_off();					\
| 		ftrace_nmi_enter();				\
| 		BUG_ON(in_nmi());				\
| 		preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET);	\

		^^^^ right there

| 		rcu_nmi_enter();				\
| 		trace_hardirq_enter();				\
| 	} while (0)