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From: Joel Fernandes <joel@joelfernandes.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Joel Fernandes <joelaf@google.com>
Subject: Re: [for-next][PATCH 3/6] tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage"
Date: Fri, 10 Aug 2018 05:22:42 -0700
Message-ID: <CAEXW_YRShy=3yPOZvr3afpD6sJ4y=rdgC-FpxjQAT31KEqstOQ@mail.gmail.com> (raw)
In-Reply-To: <20180809210654.622445925@goodmis.org>

On Thu, Aug 9, 2018 at 2:03 PM, Steven Rostedt <rostedt@goodmis.org> wrote:
> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
>
> Joel Fernandes created a nice patch that cleaned up the duplicate hooks used
> by lockdep and irqsoff latency tracer. It made both use tracepoints. But the
> latency tracer is triggering warnings when using tracepoints to call into
> the latency tracer's routines. Mainly, they can be called from NMI context.
> If that happens, then the SRCU may not work properly because on some
> architectures, SRCU is not safe to be called in both NMI and non-NMI
> context.
>
> This is a partial revert of the clean up patch c3bc8fd637a9 ("tracing:
> Centralize preemptirq tracepoints and unify their usage") that adds back the
> direct calls into the latency tracer. It also only calls the trace events
> when not in NMI.
>
> Cc: Joel Fernandes <joelaf@google.com>
> Fixes: c3bc8fd637a9 ("tracing: Centralize preemptirq tracepoints and unify their usage")
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>

thanks,

- Joel

  reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-09 21:03 [for-next][PATCH 0/6] tracing: Last minute updates before pushing to linux-next Steven Rostedt
2018-08-09 21:03 ` [for-next][PATCH 1/6] tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage" Steven Rostedt
2018-08-10 12:20   ` Joel Fernandes
2018-08-09 21:03 ` [for-next][PATCH 2/6] tracing/irqsoff: Handle preempt_count for different configs Steven Rostedt
2018-08-09 21:03 ` [for-next][PATCH 3/6] tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage" Steven Rostedt
2018-08-10 12:22   ` Joel Fernandes [this message]
2018-08-09 21:03 ` [for-next][PATCH 4/6] ftrace: Remove unused pointer ftrace_swapper_pid Steven Rostedt
2018-08-09 21:03 ` [for-next][PATCH 5/6] tracing: Fix synchronizing to event changes with tracepoint_synchronize_unregister() Steven Rostedt
2018-08-09 21:03 ` [for-next][PATCH 6/6] uprobes: Use synchronize_rcu() not synchronize_sched() Steven Rostedt

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