From: Jin Yao <[email protected]> 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 <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Kan Liang <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- 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 aae0e57c60fb..7accaf8ef689 100644 --- a/tools/perf/builtin-report.c +++ b/tools/perf/builtin-report.c @@ -399,6 +399,13 @@ 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; } -- 2.21.0

