From: Jin Yao yao.jin@linux.intel.com
[ Upstream commit 800d3f561659b5436f8c57e7c26dd1f6928b5615 ]
We received a user report that call-graph DWARF mode was enabled in 'perf record' but 'perf report' didn't unwind the callstack correctly. The reason was, libunwind was not compiled in.
We can use 'perf -vv' to check the compiled libraries but it would be valuable to report a warning to user directly (especially valuable for a perf newbie).
The warning is:
Warning: Please install libunwind development packages during the perf build.
Both TUI and stdio are supported.
Signed-off-by: Jin Yao yao.jin@linux.intel.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Andi Kleen ak@linux.intel.com Cc: Jiri Olsa jolsa@kernel.org Cc: Kan Liang kan.liang@linux.intel.com Cc: Peter Zijlstra peterz@infradead.org Link: http://lore.kernel.org/lkml/20191011022122.26369-1-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/builtin-report.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c index 4ddb0726eebcb..fd4dd12b8f9d6 100644 --- a/tools/perf/builtin-report.c +++ b/tools/perf/builtin-report.c @@ -342,6 +342,13 @@ static int report__setup_sample_type(struct report *rep) PERF_SAMPLE_BRANCH_ANY)) rep->nonany_branch_mode = true;
+#ifndef HAVE_LIBUNWIND_SUPPORT + if (dwarf_callchain_users) { + ui__warning("Please install libunwind development packages " + "during the perf build.\n"); + } +#endif + return 0; }