Messages in this thread | | | Date | Wed, 7 May 2014 19:19:14 +0200 | Subject | Re: [PATCH v3 2/3] perf record: Propagate exit status of a command line workload | From | Stephane Eranian <> |
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On Wed, May 7, 2014 at 5:04 PM, Peter Zijlstra <peterz@infradead.org> wrote: > On Wed, Apr 30, 2014 at 09:24:08AM +0900, Namhyung Kim wrote: >> Hi Jiri and Peter, >> >> On Tue, 29 Apr 2014 13:37:47 +0200, Jiri Olsa wrote: >> > On Tue, Apr 29, 2014 at 01:19:39PM +0200, Peter Zijlstra wrote: >> >> On Tue, Apr 29, 2014 at 12:56:54PM +0200, Jiri Olsa wrote: >> >> > >> >> > perf_counter tools: Propagate signals properly >> >> > commit f7b7c26e01e51fe46097e11f179dc71ce7950084 >> >> > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> >> >> > Date: Wed Jun 10 15:55:59 2009 +0200 >> >> > >> >> > but I dont think we need to do that >> >> >> >> But but but, then you're re-introducing that fail again? That no good. >> >> FYI, it's already gone with 804f7ac78803 ("perf record: handle death by >> SIGTERM"). >> >> > >> > well, I was trying the testcase you mentioned in the changelog >> > and it seemed to work for me.. ;-) I guess I was lucky to hit >> > the bash time window.. >> > >> > while :; do perf stat ./foo ; done >> > >> > so how does this work? bash will kill the loop if perf's wait >> > status is WIFSIGNALED? >> >> I'm not sure but isn't it *bash* to catch signal and terminate the >> loop? It seems the wait status of child has no business with the loop >> termination. Am I missing something? >> >> $ cat suicide.c >> #include <signal.h> >> >> int main(void) >> { >> raise(SIGTERM); >> return 0; >> } >> > > SIGTERM isn't the problem. SIGINT is. Typically when you run: > > while :; do perf stat ./foo ; done > > Its foo that is running, so when you press ^C, you'll SIGINT foo. foo > will then exit, perf stat will notice the exit, exit itself and because > the loop doesn't look at the return value of perf stat, simply > continues. > > What I want, and fixed back then, is that if you press ^C foo > terminates, perf stat/record/etc. will finish, but then terminate with > the same signal. In that case bash finally sees the SIGINT and will in > fact terminate the loop. > > try: > > $ while :; do ./foo /bin/sleep 5 ; done > > and try and break out using ^C > What I usually do here is hit ^Z, then kill the job. But I agree it would be nicer to handle this case automatically.
> --- > #include <stdio.h> > #include <stdlib.h> > #include <unistd.h> > #include <signal.h> > #include <sys/types.h> > #include <sys/wait.h> > > int main(int argc, char *argv[], char *envp[]) > { > pid_t pid = fork(); > if (!pid) /* child */ { > execve(argv[1], argv+1, envp); > perror("execve"); > return; > } > > signal(SIGINT, SIG_IGN); > waitpid(pid, NULL, 0); > return 0; > }
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