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 ADA2EC43334 for ; Mon, 4 Jul 2022 01:40:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231138AbiGDBks (ORCPT ); Sun, 3 Jul 2022 21:40:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56886 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230193AbiGDBkh (ORCPT ); Sun, 3 Jul 2022 21:40:37 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C768B6403 for ; Sun, 3 Jul 2022 18:40:36 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4AD2F612D8 for ; Mon, 4 Jul 2022 01:40:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F163C341CB; Mon, 4 Jul 2022 01:40:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1656898835; bh=7lYLGimdfIVxVsxiCFj9m/p6X1WZvyBpRdgzhdvsJH0=; h=Date:To:From:Subject:From; b=qvNQPsLY/yG9byFQI1p6za5JzHN9u8E9SFVWBSqfTFVvF5yNJL0Af25gX5cGbYmVQ Rtq0e9rVwszo3vL+I4o8tP8PyBccnw+XPMvL4OLodUbGn17kEvr1YbLtGntPr3K0Si Qbf8F9xlUkJiyu0fRWxE4JX4WKU+xxj7h8V/PLUU= Date: Sun, 03 Jul 2022 18:40:35 -0700 To: mm-commits@vger.kernel.org, songmuchun@bytedance.com, shy828301@gmail.com, osalvador@suse.de, mike.kravetz@oracle.com, liushixin2@huawei.com, linmiaohe@huawei.com, david@redhat.com, naoya.horiguchi@nec.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-hwpoison-skip-raw-hwpoison-page-in-freeing-1gb-hugepage.patch added to mm-unstable branch Message-Id: <20220704014035.9F163C341CB@smtp.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, hwpoison: skip raw hwpoison page in freeing 1GB hugepage has been added to the -mm mm-unstable branch. Its filename is mm-hwpoison-skip-raw-hwpoison-page-in-freeing-1gb-hugepage.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hwpoison-skip-raw-hwpoison-page-in-freeing-1gb-hugepage.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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 via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Naoya Horiguchi Subject: mm, hwpoison: skip raw hwpoison page in freeing 1GB hugepage Date: Mon, 4 Jul 2022 10:33:11 +0900 Currently if memory_failure() (modified to remove blocking code with subsequent patch) is called on a page in some 1GB hugepage, memory error handling fails and the raw error page gets into leaked state. The impact is small in production systems (just leaked single 4kB page), but this limits the testability because unpoison doesn't work for it. We can no longer create 1GB hugepage on the 1GB physical address range with such leaked pages, that's not useful when testing on small systems. When a hwpoison page in a 1GB hugepage is handled, it's caught by the PageHWPoison check in free_pages_prepare() because the 1GB hugepage is broken down into raw error pages before coming to this point: if (unlikely(PageHWPoison(page)) && !order) { ... return false; } Then, the page is not sent to buddy and the page refcount is left 0. Originally this check is supposed to work when the error page is freed from page_handle_poison() (that is called from soft-offline), but now we are opening another path to call it, so the callers of __page_handle_poison() need to handle the case by considering the return value 0 as success. Then page refcount for hwpoison is properly incremented so unpoison works. Link: https://lkml.kernel.org/r/20220704013312.2415700-9-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi Reviewed-by: Miaohe Lin Cc: David Hildenbrand Cc: Liu Shixin Cc: Mike Kravetz Cc: Muchun Song Cc: Oscar Salvador Cc: Yang Shi Signed-off-by: Andrew Morton --- mm/memory-failure.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/mm/memory-failure.c~mm-hwpoison-skip-raw-hwpoison-page-in-freeing-1gb-hugepage +++ a/mm/memory-failure.c @@ -1084,7 +1084,6 @@ static int me_huge_page(struct page_stat res = truncate_error_page(hpage, page_to_pfn(p), mapping); unlock_page(hpage); } else { - res = MF_FAILED; unlock_page(hpage); /* * migration entry prevents later access on error hugepage, @@ -1092,9 +1091,11 @@ static int me_huge_page(struct page_stat * subpages. */ put_page(hpage); - if (__page_handle_poison(p) > 0) { + if (__page_handle_poison(p) >= 0) { page_ref_inc(p); res = MF_RECOVERED; + } else { + res = MF_FAILED; } } @@ -1855,10 +1856,11 @@ retry: */ if (res == 0) { unlock_page(head); - res = MF_FAILED; - if (__page_handle_poison(p) > 0) { + if (__page_handle_poison(p) >= 0) { page_ref_inc(p); res = MF_RECOVERED; + } else { + res = MF_FAILED; } action_result(pfn, MF_MSG_FREE_HUGE, res); return res == MF_RECOVERED ? 0 : -EBUSY; _ Patches currently in -mm which might be from naoya.horiguchi@nec.com are mm-hugetlb-check-gigantic_page_runtime_supported-in-return_unused_surplus_pages.patch mm-hugetlb-separate-path-for-hwpoison-entry-in-copy_hugetlb_page_range.patch mm-hugetlb-make-pud_huge-and-follow_huge_pud-aware-of-non-present-pud-entry.patch mm-hwpoison-hugetlb-support-saving-mechanism-of-raw-error-pages.patch mm-hwpoison-make-unpoison-aware-of-raw-error-info-in-hwpoisoned-hugepage.patch mm-hwpoison-set-pg_hwpoison-for-busy-hugetlb-pages.patch mm-hwpoison-make-__page_handle_poison-returns-int.patch mm-hwpoison-skip-raw-hwpoison-page-in-freeing-1gb-hugepage.patch mm-hwpoison-enable-memory-error-handling-on-1gb-hugepage.patch