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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 932A1C04A6A for ; Fri, 11 Aug 2023 21:39:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231476AbjHKVje (ORCPT ); Fri, 11 Aug 2023 17:39:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236987AbjHKVjc (ORCPT ); Fri, 11 Aug 2023 17:39:32 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 543132683 for ; Fri, 11 Aug 2023 14:39:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E837467A09 for ; Fri, 11 Aug 2023 21:39:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E076C433C7; Fri, 11 Aug 2023 21:39:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1691789970; bh=KKpGLobAIF8HUegqWNTFJDMKzbP0/pVlV+z7f2QcPxU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=tQv9i5OPbstjA4C0wwvPncwznhOzGNf6nhbCtw/qr33UWETh6nY7OJzYZ3dcnjoz2 n3gUX2EHsBA39UTXUP/rwEMV+yznOdhciO0GOsTOwDIn42U/jrJdeYFFud2y2ALggl RTSPRDwmyYdMvzFI2w28UJwADTAMLZfKUeXscTkI= Date: Fri, 11 Aug 2023 14:39:29 -0700 From: Andrew Morton To: Mike Rapoport Cc: Kemeng Shi , pasha.tatashin@soleen.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] add page_ext_data to get client data in page_ext Message-Id: <20230811143929.79ee3231cbcdfbe43852a4bf@linux-foundation.org> In-Reply-To: <20230720053736.GM1901145@kernel.org> References: <20230718145812.1991717-1-shikemeng@huaweicloud.com> <20230719094421.GI1901145@kernel.org> <20230720053736.GM1901145@kernel.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 20 Jul 2023 08:37:36 +0300 Mike Rapoport wrote: > Hi, > > On Thu, Jul 20, 2023 at 10:38:39AM +0800, Kemeng Shi wrote: > > > > on 7/19/2023 5:44 PM, Mike Rapoport wrote: > > > On Tue, Jul 18, 2023 at 10:58:09PM +0800, Kemeng Shi wrote: > > >> Current client get data from page_ext by adding offset which is auto > > >> generated in page_ext core and expose the data layout design insdie > > >> page_ext core. This series adds a page_ext_data to hide offset from > > >> client. Thanks! > > > > > > Implementers of page_ext_operations are anyway intimately related to > > > page_ext, so I'm not convinced this has any value. > > > > > Hi Mike, thanks for reply. I thinks page_ext_operations can be futher splited > > into public part which used by client to simply register and private part which > > only page_ext core cares and should not be accessed by client directly > > to reduce decoupling. > > It would be easier to justify changes in this series if they were a part of > the refactoring you describe here. > > > This series makes offset to be private which client > > doesn't really care to hide data layout inside page_ext core from client. > > There are some concrete gains I can list for now: > > 1. Future client cound call page_ext_data directly instead of define a > > new function like get_page_owner to get it's data. > > 2. No change to client if layout of page_ext data change. > > These should be a part of the changelog. > I added this to the [0/N]: : Benefits include: : : 1. Future clients can call page_ext_data directly instead of defining : a new function like get_page_owner to get the data. : : 2. There is no change to clients if the layout of page_ext data changes. Mike, what is your position on this patchset now? Thanks.