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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 34428C48BE5 for ; Fri, 18 Jun 2021 03:38:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 077F46109D for ; Fri, 18 Jun 2021 03:38:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231536AbhFRDki (ORCPT ); Thu, 17 Jun 2021 23:40:38 -0400 Received: from helcar.hmeau.com ([216.24.177.18]:50748 "EHLO deadmen.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229819AbhFRDki (ORCPT ); Thu, 17 Jun 2021 23:40:38 -0400 Received: from gondobar.mordor.me.apana.org.au ([192.168.128.4] helo=gondobar) by deadmen.hmeau.com with esmtp (Exim 4.92 #5 (Debian)) id 1lu5KJ-0000aH-Fe; Fri, 18 Jun 2021 11:37:51 +0800 Received: from herbert by gondobar with local (Exim 4.92) (envelope-from ) id 1lu5Jw-0004Nh-Un; Fri, 18 Jun 2021 11:37:28 +0800 Date: Fri, 18 Jun 2021 11:37:28 +0800 From: Herbert Xu To: Ira Weiny Cc: Christoph Hellwig , Jens Axboe , Thomas Gleixner , Thomas Bogendoerfer , Geoff Levand , Ilya Dryomov , Dongsheng Yang , Mike Snitzer , "James E.J. Bottomley" , dm-devel@redhat.com, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, ceph-devel@vger.kernel.org, linux-arch@vger.kernel.org, "David S. Miller" , Christoph Lameter Subject: Re: [PATCH 01/18] mm: add a kunmap_local_dirty helper Message-ID: <20210618033728.GA16787@gondor.apana.org.au> References: <20210615132456.753241-1-hch@lst.de> <20210615132456.753241-2-hch@lst.de> <20210618030157.GA1905674@iweiny-DESK2.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210618030157.GA1905674@iweiny-DESK2.sc.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, Jun 17, 2021 at 08:01:57PM -0700, Ira Weiny wrote: > > > + flush_kernel_dcache_page(__page); \ > > Is this required on 32bit systems? Why is kunmap_flush_on_unmap() not > sufficient on 64bit systems? The normal kunmap_local() path does that. > > I'm sorry but I did not see a conclusion to my query on V1. Herbert implied the > he just copied from the crypto code.[1] I'm concerned that this _dirty() call > is just going to confuse the users of kmap even more. So why can't we get to > the bottom of why flush_kernel_dcache_page() needs so much logic around it > before complicating the general kernel users. > > I would like to see it go away if possible. This thread may be related: https://lwn.net/Articles/240249/ Cheers, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt