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=-6.8 required=3.0 tests=BAYES_00,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 8FDD6C433E7 for ; Fri, 16 Oct 2020 03:07:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3D70120897 for ; Fri, 16 Oct 2020 03:07:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602817641; bh=3816qd0+z8mShAOyGvBlm4sd1rKLHFkEvop3Fp6RSjg=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=z6SlKsUKXWkwD5RZrM1Vvl0Us8YqYzdBLYLVkGDW2GM8TusQahEK6vIJct9i0RZBG 1E82qU3HrhdjUkSC90kAOAO7uK9VsCFmauQTmWI1psOf4HUSmlwXEozZFXLDkB8twH em5IzzDQp3GaUVqQNfTWzeuioXVnzdRtMR210AuE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404492AbgJPDHU (ORCPT ); Thu, 15 Oct 2020 23:07:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:45290 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404488AbgJPDHU (ORCPT ); Thu, 15 Oct 2020 23:07:20 -0400 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 4169320878; Fri, 16 Oct 2020 03:07:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602817639; bh=3816qd0+z8mShAOyGvBlm4sd1rKLHFkEvop3Fp6RSjg=; h=Date:From:To:Subject:In-Reply-To:From; b=F6VoWQvOh/3Frg4cWn/FiB/k1J0VMEWdHMB1LqvpBjWZ7sItBVfBy2TXNb8w6LMfu 4Y7J52HlFLCiQ6qQ3cKDkX+qdN4s7H1Yb6Jl3h5DKeXNVFcrScdZT/OVp7zM6Dfq8U gc6+Csi8oLJEDGJbLndXLYCtqF8g5jxhucs5lJhw= Date: Thu, 15 Oct 2020 20:07:17 -0700 From: Andrew Morton To: akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com, aneesh.kumar@linux.vnet.ibm.com, aris@ruivo.org, cai@lca.pw, dave.hansen@intel.com, david@redhat.com, mhocko@kernel.org, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, naoya.horiguchi@nec.com, osalvador@suse.com, osalvador@suse.de, tony.luck@intel.com, torvalds@linux-foundation.org, zeil@yandex-team.ru Subject: [patch 051/156] mm,hwpoison: return 0 if the page is already poisoned in soft-offline Message-ID: <20201016030717.JQ4r1IPS5%akpm@linux-foundation.org> In-Reply-To: <20201015194043.84cda0c1d6ca2a6847f2384a@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Oscar Salvador Subject: mm,hwpoison: return 0 if the page is already poisoned in soft-offline Currently, there is an inconsistency when calling soft-offline from different paths on a page that is already poisoned. 1) madvise: madvise_inject_error skips any poisoned page and continues the loop. If that was the only page to madvise, it returns 0. 2) /sys/devices/system/memory/: When calling soft_offline_page_store()->soft_offline_page(), we return -EBUSY in case the page is already poisoned. This is inconsistent with a) the above example and b) memory_failure, where we return 0 if the page was poisoned. Fix this by dropping the PageHWPoison() check in madvise_inject_error, and let soft_offline_page return 0 if it finds the page already poisoned. Please, note that this represents a user-api change, since now the return error when calling soft_offline_page_store()->soft_offline_page() will be different. Link: https://lkml.kernel.org/r/20200922135650.1634-12-osalvador@suse.de Signed-off-by: Oscar Salvador Acked-by: Naoya Horiguchi Cc: "Aneesh Kumar K.V" Cc: Aneesh Kumar K.V Cc: Aristeu Rozanski Cc: Dave Hansen Cc: David Hildenbrand Cc: Dmitry Yakunin Cc: Michal Hocko Cc: Mike Kravetz Cc: Oscar Salvador Cc: Qian Cai Cc: Tony Luck Signed-off-by: Andrew Morton --- mm/madvise.c | 5 ----- mm/memory-failure.c | 4 ++-- 2 files changed, 2 insertions(+), 7 deletions(-) --- a/mm/madvise.c~mmhwpoison-return-0-if-the-page-is-already-poisoned-in-soft-offline +++ a/mm/madvise.c @@ -896,11 +896,6 @@ static int madvise_inject_error(int beha */ size = page_size(compound_head(page)); - if (PageHWPoison(page)) { - put_page(page); - continue; - } - if (behavior == MADV_SOFT_OFFLINE) { pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n", pfn, start); --- a/mm/memory-failure.c~mmhwpoison-return-0-if-the-page-is-already-poisoned-in-soft-offline +++ a/mm/memory-failure.c @@ -1802,7 +1802,7 @@ static int __soft_offline_page(struct pa unlock_page(page); put_page(page); pr_info("soft offline: %#lx page already poisoned\n", pfn); - return -EBUSY; + return 0; } if (!PageHuge(page)) @@ -1906,7 +1906,7 @@ int soft_offline_page(unsigned long pfn, pr_info("soft offline: %#lx page already poisoned\n", pfn); if (flags & MF_COUNT_INCREASED) put_page(page); - return -EBUSY; + return 0; } get_online_mems(); _