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From:   Kurt Kanzenbach <kurt@linutronix.de>
To:     John Stultz <john.stultz@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Stephen Boyd <sboyd@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ingo Molnar <mingo@redhat.com>,
        Jonathan Corbet <corbet@lwn.net>
Cc:     Richard Cochran <richardcochran@gmail.com>,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        Kurt Kanzenbach <kurt@linutronix.de>
Subject: [PATCH v2 0/3] tracing: Introduce trace clock tai
Date:   Thu, 14 Apr 2022 11:18:02 +0200
Message-Id: <20220414091805.89667-1-kurt@linutronix.de>
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Hi,

the Linux kernel tracing infrastructure has support for using different clocks
to generate timestamps for trace events. Especially in TSN networks it's useful
to have TAI as trace clock, because the application scheduling is done in
accordance to the network time, which is based on TAI. With a tai trace_clock in
place, it becomes very convenient to correlate network activity with Linux
kernel application traces.

However, there's no fast accessor for CLOCK_TAI yet. Therefore, patch #1 is
adding one. Patch #2 introduces the clock and the last one adds documentation
for it.

Changes since v1:

 - Add missing data_race() annotation for TAI offset which is accessed without
   any form of locking for KCSAN (Thomas)
 - Add missing documentation entry for ktime_get_tai_fast_ns()
 - Minor changelog tweaks

Previous versions:

 - https://lore.kernel.org/all/20220409081300.4762-1-kurt@linutronix.de/

Thanks,
Kurt

Kurt Kanzenbach (3):
  timekeeping: Introduce fast accessor to clock tai
  tracing: Introduce trace clock tai
  tracing: Add documentation for trace clock tai

 Documentation/core-api/timekeeping.rst |  1 +
 Documentation/trace/ftrace.rst         | 12 ++++++++++++
 include/linux/timekeeping.h            |  1 +
 kernel/time/timekeeping.c              | 17 +++++++++++++++++
 kernel/trace/trace.c                   |  1 +
 5 files changed, 32 insertions(+)

-- 
2.30.2