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=-5.3 required=3.0 tests=BAYES_00, 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 E6789C11F69 for ; Tue, 13 Jul 2021 05:46:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9126E611F1 for ; Tue, 13 Jul 2021 05:46:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9126E611F1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 854CF6B008C; Tue, 13 Jul 2021 01:46:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 804826B0095; Tue, 13 Jul 2021 01:46:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6A54E6B0096; Tue, 13 Jul 2021 01:46:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0081.hostedemail.com [216.40.44.81]) by kanga.kvack.org (Postfix) with ESMTP id 3F2276B008C for ; Tue, 13 Jul 2021 01:46:12 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 4DAFA230E2 for ; Tue, 13 Jul 2021 05:46:11 +0000 (UTC) X-FDA: 78356478942.06.FB09327 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf22.hostedemail.com (Postfix) with ESMTP id BAF861904 for ; Tue, 13 Jul 2021 05:46:10 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 6DA2F67373; Tue, 13 Jul 2021 07:46:06 +0200 (CEST) Date: Tue, 13 Jul 2021 07:46:06 +0200 From: Christoph Hellwig To: Linus Torvalds Cc: Christoph Hellwig , 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" Subject: Re: flush_kernel_dcache_page fixes and removal Message-ID: <20210713054606.GA6036@lst.de> References: <20210712060928.4161649-1-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: BAF861904 X-Stat-Signature: wph3qift6snhky3ye9mmqp44559m6cp9 Authentication-Results: imf22.hostedemail.com; dkim=none; spf=none (imf22.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de; dmarc=none X-HE-Tag: 1626155170-55133 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Jul 12, 2021 at 12:24:11PM -0700, Linus Torvalds wrote: > 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) Yeah. Once the arch maintainers look it it it might be worth to check if there is optimization potential for pages that are not in highmem and not in the page cache, as most architectures should be able to just do nothing in that case. Either way, I think getting patches 1-4 into 5.14 as bug fixes would be useful, 6 is a trivial cleanup and 5 is something we can chew on for a bit.