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Date:   Thu, 10 Jun 2021 15:32:21 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Ian Rogers <irogers@google.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        linux-perf-users <linux-perf-users@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux-trace Users <linux-trace-users@vger.kernel.org>,
        Tzvetomir Stoyanov <tz.stoyanov@gmail.com>,
        Stephane Eranian <eranian@google.com>
Subject: Re: [RFC PATCH] libtraceevent: Increase libtraceevent logging when
 verbose
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On Thu, 10 Jun 2021 11:50:00 -0700
Ian Rogers <irogers@google.com> wrote:

> #if LIBTRACE_EVENT_API > 123
> ...
> #endif
> 
> so that we can make sure perf is taking advantage of the improvements
> in the libtraceevent API?

Yes, and trace-cmd did that.

In the Makefile:

LIBTRACEEVENT_MIN_VERSION = 1.2.3
TEST_LIBTRACEEVENT = $(shell sh -c "$(PKG_CONFIG) --atleast-version $(LIBTRACEEVENT_MIN_VERSION) libtraceevent > /dev/null 2>&1 && echo y")

ifeq ("$(TEST_LIBTRACEEVENT)", "y")
CFLAGS += -DHAVE_TRACEVEVENT_API
endif

Then you can use in perf

#ifdef HAVE_TRACEEVENT_API
...
#endif

That's just one example of what you could do.

-- Steve