Date: Thu, 9 Jul 2015 11:26:56 +0200
From: Ingo Molnar <mingo@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Andy Lutomirski <luto@amacapital.net>,
        Vince Weaver <vincent.weaver@maine.edu>,
        Thomas Gleixner <tglx@linutronix.de>,
        "H. Peter Anvin" <hpa@linux.intel.com>, linux-kernel@vger.kernel.org,
        Jiri Olsa <jolsa@redhat.com>, Stephane Eranian <eranian@google.com>,
        Borislav Petkov <bp@suse.de>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Andi Kleen <ak@linux.intel.com>
Subject: Re: [RFC PATCH] perf: Provide status of known PMUs
Message-ID: <20150709092656.GA13336@gmail.com>
References: <1436428080-3098-1-git-send-email-adrian.hunter@intel.com>
 <20150709085022.GB2859@worktop.programming.kicks-ass.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20150709085022.GB2859@worktop.programming.kicks-ass.net>
User-Agent: Mutt/1.5.23 (2014-03-12)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1097
Lines: 30


* Peter Zijlstra <peterz@infradead.org> wrote:

> On Thu, Jul 09, 2015 at 10:48:00AM +0300, Adrian Hunter wrote:
>
> > Known PMUs may not be present for various reasons. Provide a way for the user 
> > to know what the reason is.
> 
> Not a bad idea, but I do wonder where we should draw the line on what is 
> 'known'. The patch as proposed will have bts/pt listed as 'known' for every arch 
> out there.
> 
> By that logic, x86 should list the ppc/sparc/mips/arm/etc.. PMUs as known and 
> wrong_arch too, which might be a tad excessive.

Absolutely x86 should list them as well - from a user POV arch dependent tooling 
sucks in general. There's nothing more annoying than trying to figure out why a 
particular tool does not work.

If memory usage becomes any concern in the future we can list them in a bit more 
compressed form.

Thanks,

	Ingo
--
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/