Re: [PATCH] perf trace: Move SIGCHLD handler init to trace__run

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Thu, Jan 06, 2022 at 11:20:30PM +0100, Jiri Olsa escreveu:
> When running perf trace with bpf object like:
>   # perf trace -e openat,/.../tools/perf/examples/bpf/hello.c
> 
> the event parsing eventually calls llvm__get_kbuild_opts function
> that runs script and that ends up with SIGCHLD delivered to perf
> trace handler, which assumes the workload process is done and quits
> perf trace.
> 
> Moving the SIGCHLD handler setup directly to trace__run, where the
> event is parsed and object already compiled.


Thanks, reproduced the problem without the patch, applied, tested again,
works.

- Arnaldo

 
> Cc: Christy Lee <christyc.y.lee@gmail.com>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
>  tools/perf/builtin-trace.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
> index 94d62a92f1a1..4282ef9ec354 100644
> --- a/tools/perf/builtin-trace.c
> +++ b/tools/perf/builtin-trace.c
> @@ -3925,6 +3925,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
>  	bool draining = false;
>  
>  	trace->live = true;
> +	signal(SIGCHLD, sig_handler);
>  
>  	if (!trace->raw_augmented_syscalls) {
>  		if (trace->trace_syscalls && trace__add_syscall_newtp(trace))
> @@ -4876,7 +4877,6 @@ int cmd_trace(int argc, const char **argv)
>  
>  	signal(SIGSEGV, sighandler_dump_stack);
>  	signal(SIGFPE, sighandler_dump_stack);
> -	signal(SIGCHLD, sig_handler);
>  	signal(SIGINT, sig_handler);
>  
>  	trace.evlist = evlist__new();
> -- 
> 2.33.1

-- 

- Arnaldo