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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 D0D67C432C2 for ; Wed, 25 Sep 2019 03:13:39 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 78C572146E for ; Wed, 25 Sep 2019 03:13:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="RKjXFpvd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 78C572146E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 075FF6B026F; Tue, 24 Sep 2019 23:13:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 026466B0270; Tue, 24 Sep 2019 23:13:38 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E57506B0271; Tue, 24 Sep 2019 23:13:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0097.hostedemail.com [216.40.44.97]) by kanga.kvack.org (Postfix) with ESMTP id C44976B026F for ; Tue, 24 Sep 2019 23:13:38 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 61E8E81C9 for ; Wed, 25 Sep 2019 03:13:38 +0000 (UTC) X-FDA: 75971972916.19.silk82_1fba2100a5324 X-HE-Tag: silk82_1fba2100a5324 X-Filterd-Recvd-Size: 3669 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf02.hostedemail.com (Postfix) with ESMTP for ; Wed, 25 Sep 2019 03:13:37 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7E2ED2075D; Wed, 25 Sep 2019 03:13:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569381216; bh=rPZsx5pEjNAHnnStBu4c+or/zobMDQhFXwTACOpn34s=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=RKjXFpvdXJESRv1aJo1URRbpigJFUTBZzXhxha7WON1XKhjva2wOAukBJ32g7+M8N mCaqJy1x1VLNMcRdN2N4D5QR4jK9Ec0B7c3Qe2FFDl8mPx+pFpujUeq9R5lGy73Rbu vaaWktmpV4Nh8h31yDew2LKwYhWd2nz0q2cqUzkY= Date: Tue, 24 Sep 2019 20:13:35 -0700 From: Andrew Morton To: Anshuman Khandual Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oscar Salvador , Michal Hocko , David Hildenbrand , Pavel Tatashin , Dan Williams Subject: Re: [PATCH] mm/hotplug: Reorder memblock_[free|remove]() calls in try_remove_memory() Message-Id: <20190924201335.0af280458bf68d7f57acb637@linux-foundation.org> In-Reply-To: References: <1568612857-10395-1-git-send-email-anshuman.khandual@arm.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, 23 Sep 2019 11:16:38 +0530 Anshuman Khandual wrote: > > > On 09/16/2019 11:17 AM, Anshuman Khandual wrote: > > In add_memory_resource() the memory range to be hot added first gets into > > the memblock via memblock_add() before arch_add_memory() is called on it. > > Reverse sequence should be followed during memory hot removal which already > > is being followed in add_memory_resource() error path. This now ensures > > required re-order between memblock_[free|remove]() and arch_remove_memory() > > during memory hot-remove. > > > > Cc: Andrew Morton > > Cc: Oscar Salvador > > Cc: Michal Hocko > > Cc: David Hildenbrand > > Cc: Pavel Tatashin > > Cc: Dan Williams > > Signed-off-by: Anshuman Khandual > > --- > > Original patch https://lkml.org/lkml/2019/9/3/327 > > > > Memory hot remove now works on arm64 without this because a recent commit > > 60bb462fc7ad ("drivers/base/node.c: simplify unregister_memory_block_under_nodes()"). > > > > David mentioned that re-ordering should still make sense for consistency > > purpose (removing stuff in the reverse order they were added). This patch > > is now detached from arm64 hot-remove series. > > > > https://lkml.org/lkml/2019/9/3/326 > > ... > > Hello Andrew, > > Any feedbacks on this, does it look okay ? > Well. I'd parked this for 5.4-rc1 processing because it looked like a cleanup. But waaaay down below the ^---$ line I see "Memory hot remove now works on arm64". Am I correct in believing that 60bb462fc7ad broke arm64 mem hot remove? And that this patch fixes a serious regression? If so, that should have been right there in the patch title and changelog!