[PATCH] perf tools: Add file-handle feature test

From: Namhyung Kim <namhyung@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Jiri Olsa <jolsa@redhat.com>, Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH] perf tools: Add file-handle feature test
Date: Thu,  2 Apr 2020 10:52:49 +0900	[thread overview]
Message-ID: <20200402015249.3800462-1-namhyung@kernel.org> (raw)
In-Reply-To: <CAM9d7cgtEXGZL+GZeLy1RmoU=jB4BfLApbsV9F=iDx6cqMh_5A@mail.gmail.com>

The file handle (FHANDLE) support is configurable so some systems might
not have it.  So add a config feature item to check it on build time
and reject cgroup tracking based on that.

Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/build/Makefile.feature           |  3 ++-
 tools/build/feature/Makefile           |  6 +++++-
 tools/build/feature/test-file-handle.c | 14 ++++++++++++++
 tools/perf/Makefile.config             |  4 ++++
 tools/perf/builtin-record.c            |  8 +++++++-
 tools/perf/builtin-top.c               |  8 +++++++-
 tools/perf/util/synthetic-events.c     |  9 +++++++++
 7 files changed, 48 insertions(+), 4 deletions(-)
 create mode 100644 tools/build/feature/test-file-handle.c

diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index 574c2e0b9d20..3e0c019ef297 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -72,7 +72,8 @@ FEATURE_TESTS_BASIC :=                  \
         setns				\
         libaio				\
         libzstd				\
-        disassembler-four-args
+        disassembler-four-args		\
+        file-handle
 
 # FEATURE_TESTS_BASIC + FEATURE_TESTS_EXTRA is the complete list
 # of all feature tests
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index 7ac0d8088565..621f528f7822 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -67,7 +67,8 @@ FILES=                                          \
          test-llvm.bin				\
          test-llvm-version.bin			\
          test-libaio.bin			\
-         test-libzstd.bin
+         test-libzstd.bin			\
+         test-file-handle.bin
 
 FILES := $(addprefix $(OUTPUT),$(FILES))
 
@@ -321,6 +322,9 @@ FLAGS_PERL_EMBED=$(PERL_EMBED_CCOPTS) $(PERL_EMBED_LDOPTS)
 $(OUTPUT)test-libzstd.bin:
 	$(BUILD) -lzstd
 
+$(OUTPUT)test-file-handle.bin:
+	$(BUILD)
+
 ###############################
 
 clean:
diff --git a/tools/build/feature/test-file-handle.c b/tools/build/feature/test-file-handle.c
new file mode 100644
index 000000000000..5f8c16f8784f
--- /dev/null
+++ b/tools/build/feature/test-file-handle.c
@@ -0,0 +1,14 @@
+#define _GNU_SOURCE
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+int main(void)
+{
+	struct file_handle fh;
+	int mount_id;
+
+	name_to_handle_at(AT_FDCWD, "/", &fh, &mount_id, 0);
+	return 0;
+}
+
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 80e55e796be9..eb95c0c0a169 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -348,6 +348,10 @@ ifeq ($(feature-gettid), 1)
   CFLAGS += -DHAVE_GETTID
 endif
 
+ifeq ($(feature-file-handle), 1)
+  CFLAGS += -DHAVE_FILE_HANDLE
+endif
+
 ifdef NO_LIBELF
   NO_DWARF := 1
   NO_DEMANGLE := 1
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 7d7912e121d6..1ab349abe904 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1433,8 +1433,14 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 	if (rec->opts.record_namespaces)
 		tool->namespace_events = true;
 
-	if (rec->opts.record_cgroup)
+	if (rec->opts.record_cgroup) {
+#ifdef HAVE_FILE_HANDLE
 		tool->cgroup_events = true;
+#else
+		pr_err("cgroup tracking is not supported\n");
+		return -1;
+#endif
+	}
 
 	if (rec->opts.auxtrace_snapshot_mode || rec->switch_output.enabled) {
 		signal(SIGUSR2, snapshot_sig_handler);
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 56b2dd0db88e..02ea2cf2a3d9 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1246,8 +1246,14 @@ static int __cmd_top(struct perf_top *top)
 
 	if (opts->record_namespaces)
 		top->tool.namespace_events = true;
-	if (opts->record_cgroup)
+	if (opts->record_cgroup) {
+#ifdef HAVE_FILE_HANDLE
 		top->tool.cgroup_events = true;
+#else
+		pr_err("cgroup tracking is not supported.\n");
+		return -1;
+#endif
+	}
 
 	ret = perf_event__synthesize_bpf_events(top->session, perf_event__process,
 						&top->session->machines.host,
diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
index 24975470ed5c..f96e84956d84 100644
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -415,6 +415,7 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool,
 	return rc;
 }
 
+#ifdef HAVE_FILE_HANDLE
 static int perf_event__synthesize_cgroup(struct perf_tool *tool,
 					 union perf_event *event,
 					 char *path, size_t mount_len,
@@ -526,6 +527,14 @@ int perf_event__synthesize_cgroups(struct perf_tool *tool,
 
 	return 0;
 }
+#else
+int perf_event__synthesize_cgroups(struct perf_tool *tool,
+				   perf_event__handler_t process,
+				   struct machine *machine)
+{
+	return -1;
+}
+#endif
 
 int perf_event__synthesize_modules(struct perf_tool *tool, perf_event__handler_t process,
 				   struct machine *machine)
-- 
2.26.0.rc2.310.g2932bb562d-goog

