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=-5.3 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_BLACK,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 24595C433E0 for ; Fri, 31 Jul 2020 20:05:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 058E022B42 for ; Fri, 31 Jul 2020 20:05:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596225947; bh=5ICL8bJgOGPr6kWpHcXj1wrxGKSn8Vtfaw7XUlAz6fI=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=HnN61sFMY8DbqAPKrdDwq6c+k30H4u8sxZRF8GeVQKjucWMCHL0qi3FhT2A/sMApT xi6saAEkqhz2RSlIuAjWg03idTAKq4VSh2HBU+bwiTZalmK0338gdacDRSEbkzA9gf zhMoJV9FjLy9LF5N6mfD5YEeU/YOd1sKiET2d0bQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726588AbgGaUFq (ORCPT ); Fri, 31 Jul 2020 16:05:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:46896 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726077AbgGaUFq (ORCPT ); Fri, 31 Jul 2020 16:05:46 -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 0D89F208E4; Fri, 31 Jul 2020 20:05:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596225945; bh=5ICL8bJgOGPr6kWpHcXj1wrxGKSn8Vtfaw7XUlAz6fI=; h=Date:From:To:Subject:In-Reply-To:From; b=mI0RNSLz6KcDf9TYg456FcFF2eCL8/QinO/FChRfEZZrJmJdIgQ4E8fjf+mRgrZRL zZe2DMBZJSXgpXix/Ve1HHNSaqI5+CfsDZmyPvFrW5/ZwD4x+cQzS6kdGKRFS5WlRU 4i2UuEyamjk7TR7BeTI2sroSNXdWwfh6FJ4hiQV8= Date: Fri, 31 Jul 2020 13:05:44 -0700 From: Andrew Morton To: aneesh.kumar@linux.ibm.com, aneesh.kumar@linux.vnet.ibm.com, cai@lca.pw, 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, osalvador@suse.de, 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: <20200731200544.VHSv1oedI%akpm@linux-foundation.org> In-Reply-To: <20200723211432.b31831a0df3bc2cbdae31b40@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(). Note that the target page is still pinned after this put_page() because the current process should have refcount from mapping. Link: http://lkml.kernel.org/r/20200731122112.11263-4-nao.horiguchi@gmail.com Signed-off-by: Naoya Horiguchi Signed-off-by: Oscar Salvador Reviewed-by: Mike Kravetz Cc: "Aneesh Kumar K.V" Cc: Aneesh Kumar K.V Cc: Dave Hansen Cc: David Hildenbrand Cc: Dmitry Yakunin Cc: Michal Hocko Cc: Naoya Horiguchi Cc: Oscar Salvador Cc: Qian Cai 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 naoya.horiguchi@nec.com are mmhwpoison-cleanup-unused-pagehuge-check.patch mm-hwpoison-remove-recalculating-hpage.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 mmhwpoison-introduce-mf_msg_unsplit_thp.patch mmhwpoison-double-check-page-count-in-__get_any_page.patch