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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 0C8A7C2BA83 for ; Wed, 12 Feb 2020 03:40:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC6A12073C for ; Wed, 12 Feb 2020 03:40:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727961AbgBLDkQ (ORCPT ); Tue, 11 Feb 2020 22:40:16 -0500 Received: from mga05.intel.com ([192.55.52.43]:25726 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727602AbgBLDkQ (ORCPT ); Tue, 11 Feb 2020 22:40:16 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Feb 2020 19:40:15 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,428,1574150400"; d="scan'208";a="380645109" Received: from hao-dev.bj.intel.com (HELO localhost) ([10.238.157.65]) by orsmga004.jf.intel.com with ESMTP; 11 Feb 2020 19:40:11 -0800 Date: Wed, 12 Feb 2020 11:19:29 +0800 From: Wu Hao To: Will Deacon Cc: mdf@kernel.org, mark.rutland@arm.com, gregkh@linuxfoundation.org, linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, atull@kernel.org, yilun.xu@intel.com, Luwei Kang Subject: Re: [PATCH v7 2/2] fpga: dfl: fme: add performance reporting support Message-ID: <20200212031929.GB5645@hao-dev> References: <1581306469-22629-1-git-send-email-hao.wu@intel.com> <1581306469-22629-3-git-send-email-hao.wu@intel.com> <20200210163400.GA21900@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200210163400.GA21900@willie-the-truck> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 10, 2020 at 04:34:01PM +0000, Will Deacon wrote: > Hi, > > On Mon, Feb 10, 2020 at 11:47:49AM +0800, Wu Hao wrote: > > This patch adds support for performance reporting private feature > > for FPGA Management Engine (FME). Now it supports several different > > performance counters, including 'basic', 'cache', 'fabric', 'vtd' > > and 'vtd_sip'. It allows user to use standard linux tools to access > > these performance counters. > > I had a quick look at this, and it mostly looks alright to me. Just a few > high-level comments/questions: Hi Will Thanks a lot for the review! :) > > - I would still prefer for the PMU drivers to live under drivers/perf/ Hm.. one possible way is to create a platform device, and introduce a new platform device driver under drivers/perf/. > > - You should probably give the PMU a better name than "fme%d", for example > "intel_fpga_dfl_fme%d". Sure. as it's not intel only, so will use "fpga_dfl_fme" or "dfl_fme" instead. > > - CPU0 can be hotplugged off on non-x86 systems. How do you cope with > that? Oh.. then we can't just always return CPU0 for cpumask, have to switch to another available cpu. Will add code to handle this case in the next version. Thanks! > > - readq() will emit 2x32-bit reads on some architectures. What happens > in this case? 64bit counter may increase and carry out of bit31 between 2-32bit reads, we probably need some more code (add extra reads?) to handle this case. Thanks again for these valuable comments, will try to fix all of them in the next version. : ) Hao > > Will