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Date: Fri, 27 Apr 2018 12:08:58 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Joel Fernandes <joelaf@google.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>,
        Tom Zanussi <tom.zanussi@linux.intel.com>,
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        baohong liu <baohong.liu@intel.com>,
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Subject: Re: [PATCH RFC] tracepoint: Introduce tracepoint callbacks
 executing with preempt on
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On Fri, 27 Apr 2018 11:43:41 -0400 (EDT)
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:

> It does so by disabling preemption in the callbacks, even when it's
> redundant with the guarantees already provided by tracepoint-sched-rcu
> and by kprobes. It's not that great for a fast-path.

Really, preempt_disable() is not bad for a fast path. It's far better
than a local_irq_disable().

-- Steve