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=-7.0 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 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 CE9B6C433DF for ; Thu, 16 Jul 2020 21:45:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A29B4207DD for ; Thu, 16 Jul 2020 21:45:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594935954; bh=oFVQ+bJLEs6MvC4TCi+4dujRvCcG+MrXQ7OzpcrdzJI=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=XKTcVt6BNyJ4llfpWX42wfgOxw3OX0Du7HsWV+fUkvncFtJg2eiPsmU7bSkBufySC eGDPRUlr+ghGb/tviP5b7rw7NQpHMK7pH2EOMSSVEhSLrerv52RmekZwbOzCKn7erj SkNBDsnvfuhQCdrAY8GCmAAjMViwVDjDx5mW+vbk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726246AbgGPVpy (ORCPT ); Thu, 16 Jul 2020 17:45:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:45596 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726002AbgGPVpy (ORCPT ); Thu, 16 Jul 2020 17:45:54 -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 E3F3320809; Thu, 16 Jul 2020 21:45:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594935953; bh=oFVQ+bJLEs6MvC4TCi+4dujRvCcG+MrXQ7OzpcrdzJI=; h=Date:From:To:Subject:In-Reply-To:From; b=YrYb2arR4KmQvTrzpvz2tzMrXNkOM/1dNz/c3EY/qGIAHkjofkK7a4UifztVbayN6 pqVF9zs40cDcvEQvPVRnxnBpqF8pVeUM4/k/IX4te7xNvOByJpGnSGZEsruvOXE/tI fG7yNpxWbXbyYnj/mMmvfjsUz9OBrojuxunJpiQE= Date: Thu, 16 Jul 2020 14:45:52 -0700 From: Andrew Morton To: aneesh.kumar@linux.vnet.ibm.com, dave.hansen@intel.com, david@redhat.com, mhocko@suse.com, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, n-horiguchi@ah.jp.nec.com, naoya.horiguchi@nec.com, osalvador@suse.com, tony.luck@intel.com, zeil@yandex-team.ru Subject: + mmmadvise-call-soft_offline_page-without-mf_count_increased.patch added to -mm tree Message-ID: <20200716214552.nkyXHoqas%akpm@linux-foundation.org> In-Reply-To: <20200703151445.b6a0cfee402c7c5c4651f1b1@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: mm-commits-owner@vger.kernel.org Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm,madvise: call soft_offline_page() without MF_COUNT_INCREASED has been added to the -mm tree. Its filename is mmmadvise-call-soft_offline_page-without-mf_count_increased.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mmmadvise-call-soft_offline_page-without-mf_count_increased.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mmmadvise-call-soft_offline_page-without-mf_count_increased.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Naoya Horiguchi Subject: mm,madvise: call soft_offline_page() without MF_COUNT_INCREASED The call to get_user_pages_fast is only to get the pointer to a struct page of a given address, pinning it is memory-poisoning handler's job, so drop the refcount grabbed by get_user_pages_fast Link: http://lkml.kernel.org/r/20200716123810.25292-4-osalvador@suse.de Signed-off-by: Naoya Horiguchi Signed-off-by: Oscar Salvador Cc: Aneesh Kumar K.V Cc: Dave Hansen Cc: David Hildenbrand Cc: Dmitry Yakunin Cc: Michal Hocko Cc: Mike Kravetz Cc: Naoya Horiguchi Cc: Tony Luck Signed-off-by: Andrew Morton --- mm/madvise.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) --- a/mm/madvise.c~mmmadvise-call-soft_offline_page-without-mf_count_increased +++ a/mm/madvise.c @@ -893,16 +893,24 @@ static int madvise_inject_error(int beha */ size = page_size(compound_head(page)); - if (PageHWPoison(page)) { - put_page(page); + /* + * The get_user_pages_fast() is just to get the pfn of the + * given address, and the refcount has nothing to do with + * what we try to test, so it should be released immediately. + * This is racy but it's intended because the real hardware + * errors could happen at any moment and memory error handlers + * must properly handle the race. + */ + put_page(page); + + if (PageHWPoison(page)) continue; - } if (behavior == MADV_SOFT_OFFLINE) { pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n", pfn, start); - ret = soft_offline_page(pfn, MF_COUNT_INCREASED); + ret = soft_offline_page(pfn, 0); if (ret) return ret; continue; @@ -910,14 +918,6 @@ static int madvise_inject_error(int beha pr_info("Injecting memory failure for pfn %#lx at process virtual address %#lx\n", pfn, start); - - /* - * Drop the page reference taken by get_user_pages_fast(). In - * the absence of MF_COUNT_INCREASED the memory_failure() - * routine is responsible for pinning the page to prevent it - * from being released back to the page allocator. - */ - put_page(page); ret = memory_failure(pfn, 0); if (ret) return ret; _ Patches currently in -mm which might be from n-horiguchi@ah.jp.nec.com are mmhwpoison-cleanup-unused-pagehuge-check.patch mmmadvise-call-soft_offline_page-without-mf_count_increased.patch mmhwpoison-inject-dont-pin-for-hwpoison_filter.patch mmhwpoison-remove-mf_count_increased.patch mmhwpoison-remove-flag-argument-from-soft-offline-functions.patch