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From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Vince Weaver <vince@deater.net>,
	Stephane Eranian <eranian@google.com>,
	Ingo Molnar <mingo@kernel.org>, Jiri Olsa <jolsa@redhat.com>,
	Andy Lutomirski <luto@amacapital.net>,
	Thomas Gleixner <tglx@linutronix.de>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFD] perf syscall error handling
Date: Mon, 3 Nov 2014 15:00:59 -0200	[thread overview]
Message-ID: <20141103170059.GC18464@kernel.org> (raw)
In-Reply-To: <20141103165019.GY10501@worktop.programming.kicks-ass.net>

Em Mon, Nov 03, 2014 at 05:50:19PM +0100, Peter Zijlstra escreveu:
> On Mon, Nov 03, 2014 at 02:25:48PM -0200, Arnaldo Carvalho de Melo wrote:
 
> > The way that peterz suggested, i.e. returning information about which
> > perf_event_attr and which of the parameters was invalid/had issues could
> > help with fallbacking/capability querying, i.e. tooling may want to use
> > some features if available automagically, fallbacking to something else
> > when that fails.
 
> > We already do that to some degree in various cases, but for some if the
> > only way that becomes available to disambiguate some EINVAL return is a
> > string, code will start having strcmps :-\

> OK, so how about we do both, the offset+mask for the tools and the
> string for the humans?

Yeah, tooling tries to provide the best it can with the offset+mask, and
if doesn't manage to do anything smart with it, just show the string and
hope that helps the user to figure out what is happening.

- Arnaldo

  reply	other threads:[~2014-11-03 17:01 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-30 22:28 [RFD] perf syscall error handling Peter Zijlstra
2014-10-31  1:16 ` Vince Weaver
2014-10-31  7:21   ` Peter Zijlstra
2014-10-31  9:27     ` Ingo Molnar
2014-10-31 12:28       ` Matt Fleming
2014-10-31 21:22         ` Stephane Eranian
2014-11-01  5:30           ` Vince Weaver
2014-11-03 16:25             ` Arnaldo Carvalho de Melo
2014-11-03 16:50               ` Peter Zijlstra
2014-11-03 17:00                 ` Arnaldo Carvalho de Melo [this message]
2014-11-03 17:12                   ` Vince Weaver
2014-11-03 17:39                     ` Peter Zijlstra
2014-11-10 10:27                   ` Ingo Molnar
2014-11-10 12:15                     ` Arnaldo Carvalho de Melo
2014-11-10 12:24                       ` Ingo Molnar
2014-11-10 13:54                         ` Arnaldo Carvalho de Melo
2014-11-10 14:14                         ` David Ahern
2014-11-10 14:47                           ` Ingo Molnar
2014-11-10 10:38           ` Ingo Molnar
2014-10-31 10:00   ` Arnaldo Carvalho de Melo

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