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 6B8E0C433EF for ; Thu, 17 Feb 2022 03:02:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232272AbiBQDDH (ORCPT ); Wed, 16 Feb 2022 22:03:07 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:43204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232277AbiBQDDH (ORCPT ); Wed, 16 Feb 2022 22:03:07 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25775FCB58 for ; Wed, 16 Feb 2022 19:02:52 -0800 (PST) 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 7696761D06 for ; Thu, 17 Feb 2022 03:02:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C7B50C004E1; Thu, 17 Feb 2022 03:02:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1645066971; bh=Tblw2/TqNjFNa9M/Z/kkdAkiijL4Ua9gaB0BWnapiA0=; h=Date:To:From:Subject:From; b=TCbQMIJ7F1tyNI/SV2t5H17u0/0MCe28Hv1cIspyYN3o7Zn8SVKeRA16kf02cvWFK rAbcHAzeHEUp+d4CFtuU4b4JmOnWFFxSm4Kv68aoMVg2pJGLvM5vrqdxOHgO2QsWbs 5FnJgX6EdlPmL9OniArbTLtiDIkyfnZsz1lyUt6Q= Date: Wed, 16 Feb 2022 19:02:51 -0800 To: mm-commits@vger.kernel.org, naoya.horiguchi@nec.com, linmiaohe@huawei.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-memory-failurec-fix-race-with-changing-page-more-robustly.patch added to -mm tree Message-Id: <20220217030251.C7B50C004E1@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/memory-failure.c: fix race with changing page more robustly has been added to the -mm tree. Its filename is mm-memory-failurec-fix-race-with-changing-page-more-robustly.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-memory-failurec-fix-race-with-changing-page-more-robustly.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-memory-failurec-fix-race-with-changing-page-more-robustly.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: Miaohe Lin Subject: mm/memory-failure.c: fix race with changing page more robustly We're only intended to deal with the non-Compound page after we split thp in memory_failure. However, the page could have changed compound pages due to race window. If this happens, we could try again to hopefully handle the page next round. Also remove unneeded orig_head. It's always equal to the hpage. So we can use hpage directly and remove this redundant one. Link: https://lkml.kernel.org/r/20220216091431.39406-5-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Cc: Naoya Horiguchi Signed-off-by: Andrew Morton --- mm/memory-failure.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) --- a/mm/memory-failure.c~mm-memory-failurec-fix-race-with-changing-page-more-robustly +++ a/mm/memory-failure.c @@ -1686,7 +1686,6 @@ int memory_failure(unsigned long pfn, in { struct page *p; struct page *hpage; - struct page *orig_head; struct dev_pagemap *pgmap; int res = 0; unsigned long page_flags; @@ -1732,7 +1731,7 @@ try_again: goto unlock_mutex; } - orig_head = hpage = compound_head(p); + hpage = compound_head(p); num_poisoned_pages_inc(); /* @@ -1813,13 +1812,18 @@ try_again: lock_page(p); /* - * The page could have changed compound pages during the locking. - * If this happens just bail out. + * We're only intended to deal with the non-Compound page here. + * However, the page could have changed compound pages due to + * race window. If this happens, we could try again to hopefully + * handle the page next round. */ - if (PageCompound(p) && compound_head(p) != orig_head) { - action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED); - res = -EBUSY; - goto unlock_page; + if (PageCompound(p)) { + if (TestClearPageHWPoison(p)) + num_poisoned_pages_dec(); + unlock_page(p); + put_page(p); + flags &= ~MF_COUNT_INCREASED; + goto try_again; } /* _ Patches currently in -mm which might be from linmiaohe@huawei.com are mm-memremap-avoid-calling-kasan_remove_zero_shadow-for-device-private-memory.patch filemap-remove-find_get_pages.patch mm-sparse-make-mminit_validate_memmodel_limits-static.patch mm-vmalloc-remove-unneeded-function-forward-declaration.patch mm-mmzoneh-remove-unused-macros.patch mm-memory-failurec-minor-clean-up-for-memory_failure_dev_pagemap.patch mm-memory-failurec-catch-unexpected-efault-from-vma_address.patch mm-memory-failurec-rework-the-signaling-logic-in-kill_proc.patch mm-memory-failurec-fix-race-with-changing-page-more-robustly.patch mm-memory-failurec-remove-pageslab-check-in-hwpoison_filter_dev.patch mm-memory-failurec-rework-the-try_to_unmap-logic-in-hwpoison_user_mappings.patch mm-memory-failurec-remove-obsolete-comment-in-__soft_offline_page.patch mm-memory-failurec-remove-unnecessary-pagetranstail-check.patch mm-balloon_compaction-make-balloon-page-compaction-callbacks-static.patch mm-memory_hotplug-remove-obsolete-comment-of-__add_pages.patch mm-memory_hotplug-avoid-calling-zone_intersects-for-zone_normal.patch mm-memory_hotplug-clean-up-try_offline_node.patch mm-memory_hotplug-fix-misplaced-comment-in-offline_pages.patch mm-highmem-remove-unnecessary-done-label.patch mm-hmmc-remove-unneeded-local-variable-ret.patch