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Date:   Fri, 18 Nov 2022 12:02:38 -0300
From:   Arnaldo Carvalho de Melo <acme@kernel.org>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Ian Rogers <irogers@google.com>, Ingo Molnar <mingo@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
        Steven Rostedt <rostedt@google.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Linux Trace Devel <linux-trace-devel@vger.kernel.org>,
        Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH v1 1/2] perf build: Require libtraceevent from the system
Message-ID: <Y3eejjLjChlGC96I@kernel.org>
References: <20221117224952.358639-1-irogers@google.com>
 <20221117224952.358639-2-irogers@google.com>
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Em Fri, Nov 18, 2022 at 10:30:45AM +0100, Peter Zijlstra escreveu:
> On Thu, Nov 17, 2022 at 02:49:51PM -0800, Ian Rogers wrote:
> > Unconditionally require libtraceevent to come from the system. Force
> > the determination of the libtracefs version if it is present.
> 
> -ENOMOTIVATION

Yeah, I was going to ask for that as well :-\

And the motivation was spelled out in the discussion that led to this
patch:

https://lore.kernel.org/lkml/CAP-5=fWxAjEia-Qbm0RVzKOxyiod8rUOBieqaGK=DtQboDe3Qw@mail.gmail.com
 
> also:
> 
> Makefile.config:1196: *** Error: libtraceevent is missing, please install libtraceevent-dev.  Stop.

yeah, this probably should work like with other libraries, don't stop
the build, just don't build features that depend on libtraceevent,
warning the user that features foo, bar and baz won't be available.

For people working with just hardware, software, cache events, no
problem.

- Arnaldo