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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 11401C10F11 for ; Thu, 25 Apr 2019 01:50:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D9EAE2175B for ; Thu, 25 Apr 2019 01:50:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388536AbfDYBuz (ORCPT ); Wed, 24 Apr 2019 21:50:55 -0400 Received: from mga07.intel.com ([134.134.136.100]:43976 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387652AbfDYBuz (ORCPT ); Wed, 24 Apr 2019 21:50:55 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Apr 2019 18:50:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,392,1549958400"; d="scan'208";a="138605892" Received: from cli6-desk1.ccr.corp.intel.com (HELO [10.239.161.118]) ([10.239.161.118]) by orsmga006.jf.intel.com with ESMTP; 24 Apr 2019 18:50:47 -0700 Subject: Re: [PATCH v17 1/3] proc: add /proc//arch_status To: Thomas Gleixner Cc: mingo@redhat.com, peterz@infradead.org, hpa@zytor.com, ak@linux.intel.com, tim.c.chen@linux.intel.com, dave.hansen@intel.com, arjan@linux.intel.com, adobriyan@gmail.com, akpm@linux-foundation.org, aubrey.li@intel.com, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Andy Lutomirski References: <20190421183529.9141-1-aubrey.li@linux.intel.com> From: "Li, Aubrey" Message-ID: Date: Thu, 25 Apr 2019 09:50:46 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/4/25 5:18, Thomas Gleixner wrote: > On Mon, 22 Apr 2019, Aubrey Li wrote: >> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig >> index 5ad92419be19..d5a9c5ddd453 100644 >> --- a/arch/x86/Kconfig >> +++ b/arch/x86/Kconfig >> @@ -208,6 +208,7 @@ config X86 >> select USER_STACKTRACE_SUPPORT >> select VIRT_TO_BUS >> select X86_FEATURE_NAMES if PROC_FS >> + select PROC_PID_ARCH_STATUS if PROC_FS > > Can you please stop mixing arch and proc code? There is no point in > enabling this on x86 right away. > >> + >> +config PROC_PID_ARCH_STATUS >> + bool "Enable /proc//arch_status file" > > Why is this switchable? x86 selects it if PROC_FS is enabled and all other > architectures are absolutely not interested in this. Above and this, I was trying to avoid an empty arch_file on other architectures. In previous proposal the entry only exists on the platform with AVX512. > >> + default n >> + help >> + Provides a way to examine process architecture specific information. >> + See for more information. > > Which contains zero information about this file when only this patch is > applied. > >> @@ -94,6 +94,7 @@ >> #include >> #include >> #include >> +#include > > That include is required because it does NOT contain anything useful for > this, right? > >> +/* >> + * Add support for task architecture specific output in /proc/pid/arch_status. >> + * task_arch_status() must be defined in asm/processor.h >> + */ >> +#ifdef CONFIG_PROC_PID_ARCH_STATUS >> +# ifndef task_arch_status >> +# define task_arch_status(m, task) >> +# endif > > What exactly is the point of this macro mess? If an architecture selects > CONFIG_PROC_PID_ARCH_STATUS then it has to provide proc_task_arch_status() > and the prototype should be in include/linux/proc_fs.h. I was trying to address Andy's last comments. If we have the prototype in include/linux/proc_fs.h, we'll have a weak function definition in fs/proc/array.c, which bloats other architectures. In that way proc_task_arch_status() should be defined in asm/processor.h, but proc_task_arch_status() has four parameters, I don't want unnecessary "struct pid_namespace *ns" and "struct pid *pid" leaked into arch headers, so I defined task_arch_status(m, task) to avoid that. > >> +static int proc_pid_arch_status(struct seq_file *m, struct pid_namespace *ns, >> + struct pid *pid, struct task_struct *task) >> +{ >> + task_arch_status(m, task); >> + return 0; >> +} >> +#endif /* CONFIG_PROC_PID_ARCH_STATUS */ > > Thanks, > > tglx > Thanks, -Aubrey