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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 4CAE0C3F2D7 for ; Tue, 3 Mar 2020 19:56:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2099A2073B for ; Tue, 3 Mar 2020 19:56:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="DcahoXq4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731501AbgCCT45 (ORCPT ); Tue, 3 Mar 2020 14:56:57 -0500 Received: from mail-wm1-f66.google.com ([209.85.128.66]:38017 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728731AbgCCT44 (ORCPT ); Tue, 3 Mar 2020 14:56:56 -0500 Received: by mail-wm1-f66.google.com with SMTP id u9so4175301wml.3; Tue, 03 Mar 2020 11:56:55 -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=37CbNVhbFufQTtYlKIlj10Tv/j2n35ElGgexHS8GKhw=; b=DcahoXq4wmP2g0InoVkEwZ9ne7HYZGOtIqHwpbrH78ZPhyKlMIXNP25prL6w7y7VhG IDRfIt4mrPa2RcIg883wHjiL/fBhJXhCFqg7PTsuNNtj6EnVB9vzmMDZ/jDGYMarV5tD W8TmNFNox9D/azYx15FF/FnRDwB15s8sCS0N6jjAYHzHwg7tevIXZT5bNokjUfiEcfco AieDlCJuZET+lNb7Pdr56OdJ9XUJRigr7NOtPCYNhRtaeYSrL4/UZudg3pwy7oyLxyRU QFomldIxO6LF6IbxPB82t1hh7xrm4Qth8lfCQdhl4ZTsun/hdWxgqJGjCNPKb/Iq+O/p SJvw== 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=37CbNVhbFufQTtYlKIlj10Tv/j2n35ElGgexHS8GKhw=; b=JdRmTNeWwrEGZiLJf6xH4VI7DtKk1IqGCBYaQyWId7S7JdTkF8WtOoaAdy6Khk3GLj A5aHIVBm0xon9xmPzz4h+F6qbP63VdokNkw0JF4PPYRPy7Og9ENEiYvetRNkz+/VkbHF IJuUkkUBvfvyx1b3kO6QuUB3RBat+94qmrJOGcErn1G1xSYitxdE8TGhDnh0fKt5xvdt UJYTsLA6K9jvnW4KrwJ44fNSyvh4iIuNWfRlzfcrwlzN03to+IwyMTc+alJS0Vuf0Nn3 Xlhjwy1mxwm46fFskJRH+Qscc4hS0yj11CCuCFjiVicMuWoB+mOFRy9Ez4G/xuBFcDPw H3ZQ== X-Gm-Message-State: ANhLgQ1BlBscY1sGtkbiPM/548tAunOWw+rW4kxLhNcJ6bHpA++hZz4o G9NSJlcG+OIwO9syjFHN/sS3F3U= X-Google-Smtp-Source: ADFU+vtr14ipf1Gev15PJYSi9koe25wZb3R+6IYXA1pPllZz5T0/1vLfbQLViYlX4FJ+cTPF976Ziw== X-Received: by 2002:a1c:6a13:: with SMTP id f19mr202513wmc.134.1583265414942; Tue, 03 Mar 2020 11:56:54 -0800 (PST) Received: from avx2 ([46.53.249.49]) by smtp.gmail.com with ESMTPSA id p10sm30460639wrx.81.2020.03.03.11.56.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Mar 2020 11:56:54 -0800 (PST) Date: Tue, 3 Mar 2020 22:56:50 +0300 From: Alexey Dobriyan To: Matthew Wilcox Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/5] Simplify /proc/$pid/maps implementation Message-ID: <20200303195650.GB17768@avx2> References: <20200229165910.24605-1-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200229165910.24605-1-willy@infradead.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 29, 2020 at 08:59:05AM -0800, Matthew Wilcox wrote: > From: "Matthew Wilcox (Oracle)" > > Back in 2005, we merged a patch from Akamai that sped up /proc/$pid/maps > by using f_version to stash the user virtual address that we'd just > displayed. That wasn't necessary; we can just use the private *ppos for > the same purpose. There have also been some other odd choices made over > the years that use the seq_file infrastructure in some non-idiomatic ways. > > Tested by using 'dd' with various different 'bs=' parameters to check that > calling ->start, ->stop and ->next at various offsets work as expected. /proc part looks OK, I only ask to include this description into first patch, so it doesn't get lost. Often 0/N patch is the most interesting part of a series.