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 9EF83C54EE9 for ; Mon, 5 Sep 2022 06:22:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236556AbiIEGWQ (ORCPT ); Mon, 5 Sep 2022 02:22:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236540AbiIEGWN (ORCPT ); Mon, 5 Sep 2022 02:22:13 -0400 Received: from out2.migadu.com (out2.migadu.com [188.165.223.204]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A34E92CE22 for ; Sun, 4 Sep 2022 23:22:12 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1662358931; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ucAIXNnH5R2gOfgMvHbR1y7ug9n/ezUmfveCIJw4IxY=; b=ASM6HcWZzDLxIDXs3ez6SRtQhvGY3pPYeVjp5UhQSb4qv3mL+xT5hh7Qb0N6USjo4XDIWS JIO6ZYdRQqpOMgdLzA+JiCmflMW8UrAFrA3yqYD3NyoawZpIBB1E6LRtznziKUchM2IOm4 6GyjKk9KlgbmHYdoU+2LrbRLBKQ9gpY= From: Naoya Horiguchi To: linux-mm@kvack.org Cc: Andrew Morton , Miaohe Lin , David Hildenbrand , Mike Kravetz , Yang Shi , Oscar Salvador , Muchun Song , Jane Chu , Naoya Horiguchi , linux-kernel@vger.kernel.org Subject: [PATCH v2 1/4] mm,hwpoison,hugetlb,memory_hotplug: hotremove memory section with hwpoisoned hugepage Date: Mon, 5 Sep 2022 15:21:34 +0900 Message-Id: <20220905062137.1455537-2-naoya.horiguchi@linux.dev> In-Reply-To: <20220905062137.1455537-1-naoya.horiguchi@linux.dev> References: <20220905062137.1455537-1-naoya.horiguchi@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Naoya Horiguchi HWPoisoned page is not supposed to be accessed once marked, but currently such accesses can happen during memory hotremove because do_migrate_range() can be called before dissolve_free_huge_pages() is called. Move dissolve_free_huge_pages() before scan_movable_pages(). Recently delayed dissolve has been implemented, so the dissolving can turn a hwpoisoned hugepage into 4kB hwpoison page, which memory hotplug can handle safely. Reported-by: Miaohe Lin Signed-off-by: Naoya Horiguchi --- mm/memory_hotplug.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index fad6d1f2262a..c24735d63b25 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1880,6 +1880,17 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages, cond_resched(); + /* + * Dissolve free hugepages in the memory block before doing + * offlining actually in order to make hugetlbfs's object + * counting consistent. + */ + ret = dissolve_free_huge_pages(start_pfn, end_pfn); + if (ret) { + reason = "failure to dissolve huge pages"; + goto failed_removal_isolated; + } + ret = scan_movable_pages(pfn, end_pfn, &pfn); if (!ret) { /* @@ -1895,17 +1906,6 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages, goto failed_removal_isolated; } - /* - * Dissolve free hugepages in the memory block before doing - * offlining actually in order to make hugetlbfs's object - * counting consistent. - */ - ret = dissolve_free_huge_pages(start_pfn, end_pfn); - if (ret) { - reason = "failure to dissolve huge pages"; - goto failed_removal_isolated; - } - ret = test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE); } while (ret); -- 2.25.1