Date:   Fri, 10 Mar 2023 22:57:46 -0800
In-Reply-To: <20230311065753.3012826-1-irogers@google.com>
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References: <20230311065753.3012826-1-irogers@google.com>
Subject: [PATCH v1 06/13] perf build: Error if jevents won't work and
 NO_JEVENTS=1 isn't set
From:   Ian Rogers <irogers@google.com>
To:     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@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>,
        Roberto Sassu <roberto.sassu@huawei.com>,
        Quentin Monnet <quentin@isovalent.com>,
        Andres Freund <andres@anarazel.de>,
        Tiezhu Yang <yangtiezhu@loongson.cn>,
        Pavithra Gurushankar <gpavithrasha@gmail.com>,
        Yang Jihong <yangjihong1@huawei.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Leo Yan <leo.yan@linaro.org>,
        "=?UTF-8?q?Martin=20Li=C5=A1ka?=" <mliska@suse.cz>,
        linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
        llvm@lists.linux.dev
Cc:     Stephane Eranian <eranian@google.com>,
        Ian Rogers <irogers@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Rather than disabling jevents if a sufficient python isn't present
error in the build. This avoids the build progressing but the binary
being degraded. The build can still succeed by specifying NO_JEVENTS=1
to the build and this is conveyed in the error message.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/Makefile.config | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 5691e2ffb1b9..2557654d8e29 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -872,14 +872,12 @@ endif
 ifneq ($(NO_JEVENTS),1)
   NO_JEVENTS := 0
   ifndef PYTHON
-    $(warning No python interpreter disabling jevent generation)
-    NO_JEVENTS := 1
+    $(error ERROR: No python interpreter needed for jevents generation. Install python or build with NO_JEVENTS=1.)
   else
     # jevents.py uses f-strings present in Python 3.6 released in Dec. 2016.
     JEVENTS_PYTHON_GOOD := $(shell $(PYTHON) -c 'import sys;print("1" if(sys.version_info.major >= 3 and sys.version_info.minor >= 6) else "0")' 2> /dev/null)
     ifneq ($(JEVENTS_PYTHON_GOOD), 1)
-      $(warning Python interpreter too old (older than 3.6) disabling jevent generation)
-      NO_JEVENTS := 1
+      $(error ERROR: Python interpreter needed for jevents generation too old (older than 3.6). Install a newer python or build with NO_JEVENTS=1.)
     endif
   endif
 endif
-- 
2.40.0.rc1.284.g88254d51c5-goog