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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 A511DC49ED7 for ; Mon, 16 Sep 2019 05:47:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A53F206C2 for ; Mon, 16 Sep 2019 05:47:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729231AbfIPFrm (ORCPT ); Mon, 16 Sep 2019 01:47:42 -0400 Received: from foss.arm.com ([217.140.110.172]:41048 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727053AbfIPFrm (ORCPT ); Mon, 16 Sep 2019 01:47:42 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5E2D4337; Sun, 15 Sep 2019 22:47:41 -0700 (PDT) Received: from p8cg001049571a15.blr.arm.com (p8cg001049571a15.blr.arm.com [10.162.43.143]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 6DF843F67D; Sun, 15 Sep 2019 22:50:08 -0700 (PDT) From: Anshuman Khandual To: linux-mm@kvack.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org Cc: Anshuman Khandual , Oscar Salvador , Michal Hocko , David Hildenbrand , Pavel Tatashin , Dan Williams Subject: [PATCH] mm/hotplug: Reorder memblock_[free|remove]() calls in try_remove_memory() Date: Mon, 16 Sep 2019 11:17:37 +0530 Message-Id: <1568612857-10395-1-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 mm/memory_hotplug.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index c73f09913165..355c466e0621 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1770,13 +1770,13 @@ static int __ref try_remove_memory(int nid, u64 start, u64 size) /* remove memmap entry */ firmware_map_remove(start, start + size, "System RAM"); - memblock_free(start, size); - memblock_remove(start, size); /* remove memory block devices before removing memory */ remove_memory_block_devices(start, size); arch_remove_memory(nid, start, size, NULL); + memblock_free(start, size); + memblock_remove(start, size); __release_memory_resource(start, size); try_offline_node(nid); -- 2.20.1