Re: [PATCH v3 1/4] perf: Enable libtracefs dynamic linking

From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Ian Rogers <irogers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	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@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-trace-devel@vger.kernel.org,
	Tzvetomir Stoyanov <tz.stoyanov@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	eranian@google.com
Subject: Re: [PATCH v3 1/4] perf: Enable libtracefs dynamic linking
Date: Tue, 28 Sep 2021 16:01:34 -0300	[thread overview]
Message-ID: <YVNmjszo792cSutx@kernel.org> (raw)
In-Reply-To: <20210923001024.550263-1-irogers@google.com>

Em Wed, Sep 22, 2021 at 05:10:21PM -0700, Ian Rogers escreveu:
> Currently libtracefs isn't used by perf, but there are potential
> improvements by using it as identified Steven Rostedt's e-mail:
> https://lore.kernel.org/lkml/20210610154759.1ef958f0@oasis.local.home/
> 
> This change is modelled on the dynamic libtraceevent patch by Michael
> Petlan:
> https://lore.kernel.org/linux-perf-users/20210428092023.4009-1-mpetlan@redhat.com/
> 
> v3. Adds file missed in v1 and v2 spotted by Jiri Olsa.

Thanks, applied.

- Arnaldo

> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/build/Makefile.feature          |  1 +
>  tools/build/feature/Makefile          |  4 ++++
>  tools/build/feature/test-libtracefs.c | 10 ++++++++++
>  tools/perf/Makefile.config            |  9 +++++++++
>  tools/perf/Makefile.perf              |  2 ++
>  5 files changed, 26 insertions(+)
>  create mode 100644 tools/build/feature/test-libtracefs.c
> 
> diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
> index 3dd2f68366f9..45a9a59828c3 100644
> --- a/tools/build/Makefile.feature
> +++ b/tools/build/Makefile.feature
> @@ -52,6 +52,7 @@ FEATURE_TESTS_BASIC :=                  \
>          libslang                        \
>          libslang-include-subdir         \
>          libtraceevent                   \
> +        libtracefs                      \
>          libcrypto                       \
>          libunwind                       \
>          pthread-attr-setaffinity-np     \
> diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
> index eff55d287db1..d024b5204ba0 100644
> --- a/tools/build/feature/Makefile
> +++ b/tools/build/feature/Makefile
> @@ -36,6 +36,7 @@ FILES=                                          \
>           test-libslang.bin                      \
>           test-libslang-include-subdir.bin       \
>           test-libtraceevent.bin                 \
> +         test-libtracefs.bin                    \
>           test-libcrypto.bin                     \
>           test-libunwind.bin                     \
>           test-libunwind-debug-frame.bin         \
> @@ -199,6 +200,9 @@ $(OUTPUT)test-libslang-include-subdir.bin:
>  $(OUTPUT)test-libtraceevent.bin:
>  	$(BUILD) -ltraceevent
>  
> +$(OUTPUT)test-libtracefs.bin:
> +	$(BUILD) -ltracefs
> +
>  $(OUTPUT)test-libcrypto.bin:
>  	$(BUILD) -lcrypto
>  
> diff --git a/tools/build/feature/test-libtracefs.c b/tools/build/feature/test-libtracefs.c
> new file mode 100644
> index 000000000000..8eff16c0c10b
> --- /dev/null
> +++ b/tools/build/feature/test-libtracefs.c
> @@ -0,0 +1,10 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <tracefs/tracefs.h>
> +
> +int main(void)
> +{
> +	struct tracefs_instance *inst = tracefs_instance_create("dummy");
> +
> +	tracefs_instance_destroy(inst);
> +	return 0;
> +}
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index 446180401e26..00ec900ddbca 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -1098,6 +1098,15 @@ ifdef LIBTRACEEVENT_DYNAMIC
>    endif
>  endif
>  
> +ifdef LIBTRACEFS_DYNAMIC
> +  $(call feature_check,libtracefs)
> +  ifeq ($(feature-libtracefs), 1)
> +    EXTLIBS += -ltracefs
> +  else
> +    dummy := $(error Error: No libtracefs devel library found, please install libtracefs-dev);
> +  endif
> +endif
> +
>  # Among the variables below, these:
>  #   perfexecdir
>  #   perf_include_dir
> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
> index e04313c4d840..7df13e74450c 100644
> --- a/tools/perf/Makefile.perf
> +++ b/tools/perf/Makefile.perf
> @@ -130,6 +130,8 @@ include ../scripts/utilities.mak
>  #
>  # Define LIBTRACEEVENT_DYNAMIC to enable libtraceevent dynamic linking
>  #
> +# Define LIBTRACEFS_DYNAMIC to enable libtracefs dynamic linking
> +#
>  
>  # As per kernel Makefile, avoid funny character set dependencies
>  unexport LC_ALL
> -- 
> 2.33.0.464.g1972c5931b-goog

-- 

- Arnaldo