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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 54F80C10F03 for ; Mon, 25 Mar 2019 14:28:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 25BD620830 for ; Mon, 25 Mar 2019 14:28:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728985AbfCYO2F (ORCPT ); Mon, 25 Mar 2019 10:28:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60288 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725788AbfCYO2E (ORCPT ); Mon, 25 Mar 2019 10:28:04 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id 9480288304; Mon, 25 Mar 2019 14:28:04 +0000 (UTC) Received: from segfault.boston.devel.redhat.com (segfault.boston.devel.redhat.com [10.19.60.26]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 729CC842B2; Mon, 25 Mar 2019 14:28:02 +0000 (UTC) From: Jeff Moyer To: Michal Hocko Cc: Dan Williams , Andrew Morton , =?utf-8?B?SsOpcsO0bWU=?= Glisse , Logan Gunthorpe , Toshi Kani , Vlastimil Babka , stable , Linux MM , linux-nvdimm , Linux Kernel Mailing List Subject: Re: [PATCH v5 00/10] mm: Sub-section memory hotplug support References: <155327387405.225273.9325594075351253804.stgit@dwillia2-desk3.amr.corp.intel.com> <20190322180532.GM32418@dhcp22.suse.cz> <20190325101945.GD9924@dhcp22.suse.cz> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 Date: Mon, 25 Mar 2019 10:28:00 -0400 In-Reply-To: <20190325101945.GD9924@dhcp22.suse.cz> (Michal Hocko's message of "Mon, 25 Mar 2019 11:19:45 +0100") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Mon, 25 Mar 2019 14:28:04 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Michal Hocko writes: >> > and I would like to know that you are >> > not just shifting the problem to a smaller unit and a new/creative HW >> > will force us to go even more complicated. >> >> HW will not do this to us. It's software that has the problem. >> Namespace creation is unnecessarily constrained to 128MB alignment. > > And why is that a problem? A lack of documentation that this is a > requirement? Something will not work with a larger alignment? Someting > else? See this email for one user-visible problem: https://lore.kernel.org/lkml/x49imxbx22d.fsf@segfault.boston.devel.redhat.com/ Cheers, Jeff