From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1751714AbdBOKNs (ORCPT <rfc822;w@1wt.eu>);
        Wed, 15 Feb 2017 05:13:48 -0500
Received: from mail.skyhub.de ([78.46.96.112]:56985 "EHLO mail.skyhub.de"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1751317AbdBOKNr (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Wed, 15 Feb 2017 05:13:47 -0500
Date: Wed, 15 Feb 2017 11:13:23 +0100
From: Borislav Petkov <bp@alien8.de>
To: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Jiri Olsa <jolsa@kernel.org>, Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
        peterz@infradead.org, joro@8bytes.org, mingo@redhat.com
Subject: Re: [PATCH v9 0/8] perf/amd/iommu: Enable multi-IOMMU support
Message-ID: <20170215101323.ecggpvbkbcqaq5xs@pd.tnic>
References: <1486456836-17428-1-git-send-email-Suravee.Suthikulpanit@amd.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <1486456836-17428-1-git-send-email-Suravee.Suthikulpanit@amd.com>
User-Agent: NeoMutt/20161014 (1.7.1)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, Feb 07, 2017 at 02:40:28AM -0600, Suravee Suthikulpanit wrote:
> From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
> 
> This patch series modifies the existing IOMMU and Perf drivers to support
> systems with multiple IOMMUs by allocating an amd_iommu PMU per IOMMU instance.
> This allows users to specify performance events and filters separately for each
> IOMMU.
> 
> This has been tested on the new family17h-based server w/ multiple IOMMUs.

Ok, so far so good.

There's just one thing:

$ perf stat -e amd_iommu_X/Y

says <not supported> and only doing the system wide tracing with -a does
it count events.

So, lemme ask perf tool people, can we guys make the -a thing default
when detect that we're running only uncore events which all should need
-a anyway?

Otherwise people who, like me, don't know that, would try to do
measurements and see the <not supported> and wonder...

Lemme add some more people to CC.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.