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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 82D24C07E9C for ; Mon, 12 Jul 2021 19:24:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 578A1610FA for ; Mon, 12 Jul 2021 19:24:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233614AbhGLT1V (ORCPT ); Mon, 12 Jul 2021 15:27:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234973AbhGLT1U (ORCPT ); Mon, 12 Jul 2021 15:27:20 -0400 Received: from mail-lf1-x133.google.com (mail-lf1-x133.google.com [IPv6:2a00:1450:4864:20::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E09CC0613E5 for ; Mon, 12 Jul 2021 12:24:31 -0700 (PDT) Received: by mail-lf1-x133.google.com with SMTP id f30so45482545lfj.1 for ; Mon, 12 Jul 2021 12:24:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=r3C0MNcdPuaQMoy2DZLesW5CVXpDYfQzTqrwGXdHaRg=; b=MJrdQt/xj/X89L2akDuRIxLQO4djMTLLgU8eBvU6YVC8dUlC07Y6kHh4rBlkT1q7MV Ea7nnfbhd2stzRZFtdTC0KqSjngvfVy93JncJKAiLwNmjmfcozdphfyI2xTiy3uOptFv Vhn12vpbGZd8c3Bo7seoaaiJzsRoQUlb47+hA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=r3C0MNcdPuaQMoy2DZLesW5CVXpDYfQzTqrwGXdHaRg=; b=A2PFlAkj5e4lpSg4j+FqMRiPCqd2zY14tjEb6axzurn+/gUAyj3jj3vZxUpVWA5vHK 4sbHctFATSdXkHC7yRizjAQ1XqyT/ZJd9t0ZYN774vLnpWt5pkKeJxZYH7gCNyGYqVrG VubD2Rc3T1ft5Eldc0ksCyxoYcwBfrpkQcy7oBhGBQhy1/eVVR0+xU4Q9NJUd1dBjIrM VmaLKxHq6Dhh7GFdwpSMto/0K1SmweUR53j5ITOebWUHwtU4mWcXbBZi7btCAmfCWoUX DSpPtWCcuaMUsCkZ54PRJvNFFeNYGsLYSLmBd8reJG+9nPprTkNXNkCdbqwFqKNZ3t36 AcYA== X-Gm-Message-State: AOAM531c7TsznUpi/dKc44UiuCNlF+yWzV2HKbuwikrxmVDodT0Emojq bfaM1ZGAwiF+rTeUjn37U90lemK+qATOXa8h X-Google-Smtp-Source: ABdhPJwQVkZ+TaeYrzG2fuLNYCDOKvMLJrvXTh2I8LXEHvwwH76C5OyEp3vzk19OXNPFDWteIix2Jg== X-Received: by 2002:a05:6512:90f:: with SMTP id e15mr240978lft.275.1626117869185; Mon, 12 Jul 2021 12:24:29 -0700 (PDT) Received: from mail-lj1-f178.google.com (mail-lj1-f178.google.com. [209.85.208.178]) by smtp.gmail.com with ESMTPSA id c25sm301328lja.16.2021.07.12.12.24.27 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 12 Jul 2021 12:24:28 -0700 (PDT) Received: by mail-lj1-f178.google.com with SMTP id u25so26002647ljj.11 for ; Mon, 12 Jul 2021 12:24:27 -0700 (PDT) X-Received: by 2002:a2e:9241:: with SMTP id v1mr639513ljg.48.1626117867421; Mon, 12 Jul 2021 12:24:27 -0700 (PDT) MIME-Version: 1.0 References: <20210712060928.4161649-1-hch@lst.de> In-Reply-To: <20210712060928.4161649-1-hch@lst.de> From: Linus Torvalds Date: Mon, 12 Jul 2021 12:24:11 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: flush_kernel_dcache_page fixes and removal To: Christoph Hellwig Cc: Andrew Morton , "James E.J. Bottomley" , Russell King , Guo Ren , Thomas Bogendoerfer , Nick Hu , Greentime Hu , Vincent Chen , Helge Deller , Yoshinori Sato , Rich Felker , Geoff Levand , Paul Cercueil , Ulf Hansson , Alex Shi , Linux Kernel Mailing List , Linux ARM , linux-csky@vger.kernel.org, "open list:BROADCOM NVRAM DRIVER" , linux-parisc@vger.kernel.org, Linux-sh list , linux-mmc@vger.kernel.org, linux-scsi , Linux-MM , "open list:DOCUMENTATION" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Sun, Jul 11, 2021 at 11:09 PM Christoph Hellwig wrote: > > I think we should just remove it and eat the very minor overhead in > exec rather than confusing poor driver writers. Ack. I think architectures that have virtual caches might want to think about this patch a bit more, but on the whole I can't argue against the "it's badly documented and misused". No sane architecture will care, since dcache will be coherent (there are more issues on the I$ side, but that's a different issue) Linus