Re: [PATCH 5/7] perf top: Delay UI browser setup after initialization is done

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

Em Thu, Dec 10, 2015 at 02:52:05PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Thu, Dec 10, 2015 at 02:43:32PM -0300, Arnaldo Carvalho de Melo escreveu:
> > Em Thu, Dec 10, 2015 at 12:00:57PM +0900, Namhyung Kim escreveu:
> > > Move setup_browser after all necessary initialization is done.  This
> > > is to remove the browser dependency from usage_with_options() and
> > > friends.
> > 
> > So, please try:
> > 
> > perf top -C 0 -p 1
> > 
> > So that we get a command line validation error that will cause cmd_top
> > to trip this:
> > 
> >         status = target__validate(target);
> >         if (status) {
> >                 target__strerror(target, status, errbuf, BUFSIZ);
> >                 ui__warning("%s\n", errbuf);
> >         }
> > 
> > ui__warning() will emit the warning to stdio, and this message will be
> > seen only after the user exits the tool:
> 
> So, this one should be enough, ack?

        if (perf_evlist__create_maps(top.evlist, target) < 0) {
-               ui__error("Not enough memory to create thread/cpu maps\n");
+               ui__error("Couldn't create thread/CPU maps: %s\n",
+                         errno == ENOENT ? "No such process" : strerror_r(errno, errbuf, sizeof(errbuf)));
                goto out_delete_evlist;
        }
 
I'm adding "Introduce perf_evlist__strerror_create_maps()" to my TODO list
at https://perf.wiki.kernel.org/index.php/Todo
 
> From 83c5eb5124210a579f174d37af8f0ce4f21264ff Mon Sep 17 00:00:00 2001
> From: Arnaldo Carvalho de Melo <acme@redhat.com>
> Date: Thu, 10 Dec 2015 14:48:45 -0300
> Subject: [PATCH] perf report: Do show usage message when failing to create
>  cpu/thread maps
> 
> This is necessary to get rid of the browser dependency from
> usage_with_options() and its friends.  Because we validate the targets
> which are used to create the cpu/thread maps and inform the user about
> any override performed via the chosen UI, we don't need to call the
> usage routine for that.


> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Josh Poimboeuf <jpoimboe@redhat.com>
> Cc: David Ahern <dsahern@gmail.com>
> Cc: Jiri Olsa <jolsa@redhat.com>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Link: http://lkml.kernel.org/n/tip-slu7lj7buzpwgop1vo9la8ma@git.kernel.org
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> ---
>  tools/perf/builtin-top.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
> index 7e2e72e6d9d1..4eb9c6906219 100644
> --- a/tools/perf/builtin-top.c
> +++ b/tools/perf/builtin-top.c
> @@ -1279,8 +1279,10 @@ int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
>  	if (target__none(target))
>  		target->system_wide = true;
>  
> -	if (perf_evlist__create_maps(top.evlist, target) < 0)
> -		usage_with_options(top_usage, options);
> +	if (perf_evlist__create_maps(top.evlist, target) < 0) {
> +		ui__error("Not enough memory to create thread/cpu maps\n");
> +		goto out_delete_evlist;
> +	}
>  
>  	if (!top.evlist->nr_entries &&
>  	    perf_evlist__add_default(top.evlist) < 0) {
> -- 
> 1.8.3.1
>