Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751517Ab2EGRnQ (ORCPT ); Mon, 7 May 2012 13:43:16 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:48899 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750777Ab2EGRnO (ORCPT ); Mon, 7 May 2012 13:43:14 -0400 Message-ID: <4FA809AD.7060209@gmail.com> Date: Mon, 07 May 2012 11:43:09 -0600 From: David Ahern User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Arnaldo Carvalho de Melo CC: Namhyung Kim , Peter Zijlstra , Paul Mackerras , Ingo Molnar , Namhyung Kim , LKML Subject: Re: [PATCH 5/7] perf tools: Introduce perf_target__strerror() References: <1336367344-28071-1-git-send-email-namhyung.kim@lge.com> <1336367344-28071-6-git-send-email-namhyung.kim@lge.com> <20120507172946.GC2485@infradead.org> In-Reply-To: <20120507172946.GC2485@infradead.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2402 Lines: 71 On 5/7/12 11:29 AM, Arnaldo Carvalho de Melo wrote: > Em Mon, May 07, 2012 at 02:09:02PM +0900, Namhyung Kim escreveu: >> The perf_target__strerror() sets @buf to a string that >> describes the (perf_target-specific) error condition >> that is passed via @errnum. >> >> This is similar to strerror_r() and does same thing if >> @errnum has a standard errno value. > > This has a problem: why should I be warned when I do, as root: > > # perf top -u acme > > It warns me that "UID switch overriding SYSTEM", yeah, right that is > what I asked, no need to tell me that :-) > > So what is missing in this case is that top starts with system_wide set, > not from the command line. > > I.e. if I had asked for: > > # perf top --system_wide --user acme > > Ok, the warning would make sense. > > So just special case this in the top case, I think, like the patch > below, ack? > > I'll fold this into this patch and add a [ committer note: ... ] > > Ack? > > - Arnaldo > > diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c > index a2518fc..780791f 100644 > --- a/tools/perf/builtin-top.c > +++ b/tools/perf/builtin-top.c > @@ -1257,7 +1257,16 @@ int cmd_top(int argc, const char **argv, const char *prefix __used) > setup_browser(false); > > status = perf_target__validate(&top.target); > - if (status != PERF_ERRNO_TARGET__SUCCESS) { > + if (status != PERF_ERRNO_TARGET__SUCCESS&& > + status != PERF_ERRNO_TARGET__PID_OVERRIDE_SYSTEM&& > + status != PERF_ERRNO_TARGET__UID_OVERRIDE_SYSTEM) { > + /* > + * Top doesn't provide an explicit way to ask for system wide > + * profiling, it is the default. > + * > + * So we shouldn't warn the user when he/she asks for --pid or > + * --uid. > + */ > perf_target__strerror(&top.target, status, errbuf, BUFSIZ); > ui__warning("%s", errbuf); > } Seems like we should avoid the propagation of the errnos beyond the depths of the library part. For perf-top why not default to nothing set and if the user does not request one, set system wide. i.e, following Patch 6 in this set do: if (perf_target__none(&top.target) top.target.system_wide = true; David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/