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 38EA5C07E95 for ; Tue, 13 Jul 2021 05:46:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1908C608FE for ; Tue, 13 Jul 2021 05:46:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229902AbhGMFtA (ORCPT ); Tue, 13 Jul 2021 01:49:00 -0400 Received: from verein.lst.de ([213.95.11.211]:57348 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229581AbhGMFtA (ORCPT ); Tue, 13 Jul 2021 01:49:00 -0400 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) Precedence: bulk List-ID: X-Mailing-List: linux-csky@vger.kernel.org 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. 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=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 D94ACC07E95 for ; Tue, 13 Jul 2021 05:47:53 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A49CE61004 for ; Tue, 13 Jul 2021 05:47:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A49CE61004 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=9oo6lq2HzA3M9jtfR+Txk7OlZKZfR2+xmWJjLXxlv10=; b=IV9Da+HiZiJU3X SfWToR3YqKs0x3vfsSyd0OtX2PzdvhgAf6hb+QCVVdaXjDMlR2BI9wxL9LGlslELqzvPD1mHbBq9L mXW03WEeszjjDnklTbcSqU7RYPzyBo7RZgWlJMWC7gmmqeRzguvxd/KAPcXwmKu2RTCrw8qAaAIDC CgMBAH+btZbPfxjqYsxE/EJZQ07B43vXRHrp4XXXYbojoIolVjEUYqD75fyrOlraR+oe8G0JO47HO mG81ufPd14Ezyil2+07pmOB5XYajxtbtd6MOSshpSHxhSbylntqab0kKZJglliaFA/X7Xx3tOhx4w ip+gt+xoAjYAKCppWVMg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m3BFK-009B3v-I7; Tue, 13 Jul 2021 05:46:18 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m3BFH-009B2S-5a for linux-arm-kernel@lists.infradead.org; Tue, 13 Jul 2021 05:46:16 +0000 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-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210712_224615_399992_BDAE74DE X-CRM114-Status: GOOD ( 18.20 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel