From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3AC69C49EA6 for ; Thu, 24 Jun 2021 17:49:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 12C4F613C5 for ; Thu, 24 Jun 2021 17:49:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232506AbhFXRwF (ORCPT ); Thu, 24 Jun 2021 13:52:05 -0400 Received: from mga11.intel.com ([192.55.52.93]:5641 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231407AbhFXRwD (ORCPT ); Thu, 24 Jun 2021 13:52:03 -0400 IronPort-SDR: vk4NrxwoQKmi6tjevlZMKVmfs25YFhSgyx9wXStqpasdDnIXkSDfY+cDsAyynB/QVfGDNZ09IB nyzxhFXM4Dwg== X-IronPort-AV: E=McAfee;i="6200,9189,10025"; a="204519317" X-IronPort-AV: E=Sophos;i="5.83,296,1616482800"; d="scan'208";a="204519317" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Jun 2021 10:49:44 -0700 IronPort-SDR: SfVF8QNFENIjP2+AkMOtwdg4oRmtBGnPnJo5206IEx8McrFWCf9qUXCkpCprZV9Typ+y0nZ2Xv tto7YZe6Zgiw== X-IronPort-AV: E=Sophos;i="5.83,296,1616482800"; d="scan'208";a="406720618" Received: from akleen-mobl1.amr.corp.intel.com (HELO [10.209.74.185]) ([10.209.74.185]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Jun 2021 10:49:43 -0700 Subject: Re: [PATCH 2/7] perf: Create a symlink for a PMU To: Greg KH , "Liang, Kan" Cc: peterz@infradead.org, mingo@redhat.com, linux-kernel@vger.kernel.org, eranian@google.com, namhyung@kernel.org, acme@kernel.org, jolsa@redhat.com References: <1624497729-158864-1-git-send-email-kan.liang@linux.intel.com> <1624497729-158864-3-git-send-email-kan.liang@linux.intel.com> <1e536604-cf93-0f09-401e-2073924c5582@linux.intel.com> <33bccec9-c4c4-d52b-9ee4-9a09e7353812@linux.intel.com> From: Andi Kleen Message-ID: <1d77c148-7ea6-4631-d799-e8ec3d31f347@linux.intel.com> Date: Thu, 24 Jun 2021 10:49:42 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > That is not how sysfs and the driver model works, sorry. You don't get > to keep both names, otherwise sysfs would be even more of a mess than it > currently is. What happens if you need "another" name in the future? > When do you stop I don't see any scenario where we would ever need more than a single symlink. I believe there is already precedent for this elsewhere. > > this isn't ok, please do it right. I don't see what exactly are you proposing. Are you proposing to break every perf script on a kernel update? Doesn't seem acceptable to me. Or move the compatibility into the perf tool? That would require the users to both update the perf tool and the kernel. I suppose it would be possible, but it would be totally against the standard perf abstraction design. Besides there are other consumers of this than just the perf tool, so it could possibly have a wide impact. -Andi