From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-6.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id D5B1D7D04D for ; Mon, 7 Jan 2019 23:49:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727349AbfAGXtG (ORCPT ); Mon, 7 Jan 2019 18:49:06 -0500 Received: from mail-ed1-f65.google.com ([209.85.208.65]:43759 "EHLO mail-ed1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727344AbfAGXtG (ORCPT ); Mon, 7 Jan 2019 18:49:06 -0500 Received: by mail-ed1-f65.google.com with SMTP id f9so2500187eds.10; Mon, 07 Jan 2019 15:49:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=m66FkWzWK4Ca77T0mttzUwdOm6hMUj5wpz7jHygHJxo=; b=eR5gGUCy+edoG5lufynRkfMK1ZnXTroQawfDEOHX720Qp39G6thntFAbwqcwQSlg4H 4WWwbW4sllzYlwrOIaNUYI5ER9jHca/HEexMa+Y94H9JSi9iKT9LIW8HfdrjtOxC3Ywb tOtBKeCrU09xM+wSxmvkPK1SkHN0wXssY8EOxcoLq7xvjEO8xDrcv6FfBfL6NKR7OmLg KLJcCFl7dmM00/J/FuhJahrImviagC3c74hurd8mz3nN2nl5+KwYErZqjns366dvtdOI oxrB+HkUUPhKhzzGZqx8IkiP8CNJlHYdAGDBrAl7osYwGg7U37MHbCcUwfm0cVYhmo6F tcqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=m66FkWzWK4Ca77T0mttzUwdOm6hMUj5wpz7jHygHJxo=; b=HqLJj12GFS55XV4GDo/qUpYCA4P0rLqpBw/FXoyhnM6GSk55kzsLwsGwhwmV2hRgIN vRFhWVuNnVGQYBdbsEbFx7B0aFPNTq242FAtcMG7iJxgs/6g1fibhHw9LjA5I7QmP6Ty sNbfeCc4Gy16NaqYpgbxayHTQdUykWzdG/GNCqnE+W9WCXlDAdSA1fGNGWnsLR0USGYL WerjD516YtHv2GIpT28Bx7o/sjrTmu8RbUmfL908GGHuyezXnIBEuUk//cT58d3X9zA1 nisAiZKlgOwbu1lhzHFTf9hf9mUtfSdg3l96y0GuANwGHU4Y5GsIIea8D5aigWVO7aBD 5QnA== X-Gm-Message-State: AA+aEWbsotfWVRiyPI0+wnAP/FD2Hd3jWJaGbOyB0xYU37qM/KY3CNlE uP4kuqFNlFuGGox9dMvRXg== X-Google-Smtp-Source: AFSGD/VTzSZXm/YVb+GAuWqfE/hv7XupYD0muTh3KDqpqeQxobehQ109nixgXckZyJZh9CkrBVUrFg== X-Received: by 2002:a50:f5af:: with SMTP id u44mr59193359edm.172.1546904944649; Mon, 07 Jan 2019 15:49:04 -0800 (PST) Received: from avx2 (nat-minsk-pool-46-53-201-92.telecom.by. [46.53.201.92]) by smtp.gmail.com with ESMTPSA id m14sm39056388edc.27.2019.01.07.15.49.03 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 07 Jan 2019 15:49:04 -0800 (PST) Date: Tue, 8 Jan 2019 02:49:01 +0300 From: Alexey Dobriyan To: Daniel Colascione Cc: Dave Chinner , Waiman Long , Andrew Morton , Luis Chamberlain , Kees Cook , Jonathan Corbet , linux-kernel , "open list:DOCUMENTATION" , Linux FS Devel , Davidlohr Bueso , Miklos Szeredi , Randy Dunlap Subject: Re: [PATCH 0/2] /proc/stat: Reduce irqs counting performance overhead Message-ID: <20190107234901.GA27074@avx2> References: <1546873978-27797-1-git-send-email-longman@redhat.com> <20190107223214.GZ6311@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Mon, Jan 07, 2019 at 05:41:28PM -0500, Daniel Colascione wrote: > There should be a general-purpose way for /proc file readers to tell > the kernel which bits of information interest them on a particular read > syscall sequence or particular open(2) or something. This opens a pandora box full of ioctls. /proc supports ioctls on files which aren't /proc/$PID and /proc/sys/* though. So people made a mess with allegedly easy text files and now they continue to make even more mess adding ioctls on top.