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=-4.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 21C9BC4363D for ; Wed, 7 Oct 2020 14:49:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD947212CC for ; Wed, 7 Oct 2020 14:49:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HLToJCYG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728677AbgJGOtG (ORCPT ); Wed, 7 Oct 2020 10:49:06 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:38726 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728571AbgJGOtG (ORCPT ); Wed, 7 Oct 2020 10:49:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602082145; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=nG6n8iQw6ndSbR0MV2n6BWmlRza/GffluKmq0dVxVlg=; b=HLToJCYGkzEWh11G0epCeOud1ToWSWEq6CFt476W7gxn8hOelsmTWBxswGF6cwrYxq6CFR Yr1nRX8NEZ1oX1U3IYgxi1NWI2auBd4tBAMRp7BzBSKvG5Otag0PFlUPF0Ib/0t2y786bT jzQLs7mrtOCUlA5eysc0Q9fcmNP8QMo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-558-4qnaVhh2M-CFZ1ehWGyQdQ-1; Wed, 07 Oct 2020 10:49:03 -0400 X-MC-Unique: 4qnaVhh2M-CFZ1ehWGyQdQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4EEA3804024; Wed, 7 Oct 2020 14:48:38 +0000 (UTC) Received: from redhat.com (ovpn-119-161.rdu2.redhat.com [10.10.119.161]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 383A95579D; Wed, 7 Oct 2020 14:48:37 +0000 (UTC) Date: Wed, 7 Oct 2020 10:48:35 -0400 From: Jerome Glisse To: Matthew Wilcox Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Andrew Morton , Alexander Viro , Tejun Heo , Jan Kara , Josef Bacik Subject: Re: [PATCH 00/14] Small step toward KSM for file back page. Message-ID: <20201007144835.GA3471400@redhat.com> References: <20201007010603.3452458-1-jglisse@redhat.com> <20201007032013.GS20115@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20201007032013.GS20115@casper.infradead.org> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 07, 2020 at 04:20:13AM +0100, Matthew Wilcox wrote: > On Tue, Oct 06, 2020 at 09:05:49PM -0400, jglisse@redhat.com wrote: > > The present patchset just add mapping argument to the various vfs call- > > backs. It does not make use of that new parameter to avoid regression. > > I am posting this whole things as small contain patchset as it is rather > > big and i would like to make progress step by step. > > Well, that's the problem. This patch set is gigantic and unreviewable. > And it has no benefits. The idea you present here was discussed at > LSFMM in Utah and I recall absolutely nobody being in favour of it. > You claim many wonderful features will be unlocked by this, but I think > they can all be achieved without doing any of this very disruptive work. You have any ideas on how to achieve them without such change ? I will be more than happy for a simpler solution but i fail to see how you can work around the need for a pointer inside struct page. Given struct page can not grow it means you need to be able to overload one of the existing field, at least i do not see any otherway. Cheers, Jérôme