Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 6 Jan 2023 15:49:56 +0100
From:   Borislav Petkov <bp@alien8.de>
To:     "Zhang, Rui" <rui.zhang@intel.com>
Cc:     "Hansen, Dave" <dave.hansen@intel.com>,
        "ak@linux.intel.com" <ak@linux.intel.com>,
        "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
        "x86@kernel.org" <x86@kernel.org>,
        "peterz@infradead.org" <peterz@infradead.org>,
        "linux-perf-users@vger.kernel.org" <linux-perf-users@vger.kernel.org>,
        "mingo@redhat.com" <mingo@redhat.com>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "kan.liang@linux.intel.com" <kan.liang@linux.intel.com>,
        "Bityutskiy, Artem" <artem.bityutskiy@intel.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] perf/x86/rapl: Add support for Intel Meteor Lake
Message-ID: <Y7g1FCY4Y+hY26aC@zn.tnic>
References: <20230104145831.25498-1-rui.zhang@intel.com>
 <25d07838-3904-a086-4238-f56c9424b53a@intel.com>
 <ea9186869cca50a21efcc1a9cc4dbe5adcd1784b.camel@intel.com>
 <Y7aejeHDpLlwwYbr@zn.tnic>
 <4cc5cd868b20366fc9d4bf157656e0c295074282.camel@intel.com>
 <Y7f6RhF8FuK9R399@zn.tnic>
 <d6ae35f1e72d4bb8e02f44fe6d9369f1a5f21619.camel@intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <d6ae35f1e72d4bb8e02f44fe6d9369f1a5f21619.camel@intel.com>
Precedence: bulk

On Fri, Jan 06, 2023 at 02:38:10PM +0000, Zhang, Rui wrote:
> And then set the feature flags based on this, and make the drivers test
> the feature flags.

That would be the purpose of synthetic flags.

> The goal of this is to do model list update in one place instead of 4
> or more different drivers when a new model comes.

Do you really have to update 4 different places each time?

As said before, you have to do the model matching *somewhere*. If you have to do
model matching in a lot of drivers - and it looks like you do - judging by

$ git grep X86_MATCH_INTEL_FAM6

output, then doing the matching once in cpu/intel.c and setting a synthetic flag
does make sense because all that matching code will disappear from all the
drivers but be concentrated in one place.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette