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 DF7DCC5ACB2 for ; Wed, 15 Nov 2023 23:30:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230412AbjKOXaz (ORCPT ); Wed, 15 Nov 2023 18:30:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60252 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233640AbjKOXav (ORCPT ); Wed, 15 Nov 2023 18:30:51 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7A7218B; Wed, 15 Nov 2023 15:30:47 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5DF2C433C9; Wed, 15 Nov 2023 23:30:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1700091047; bh=frawxDI6pFC4U1i3NrbTABbYzQCmAnshlQ2wM5qQOBs=; h=Date:To:From:Subject:From; b=1/9fYDpVa9W+fgxzSOTxo6PzMr5nL5sPwswS9x+hjF+AVTIKBMl7vsmXCOqatiQZQ kz0p8gdGu5fvMa0Zdc0GtvJYRUotAJS+hJBjCvVbeLSW5bl6x4xP2wgEj7/Gvc9lRx df9IDvZx+aup5X8dUbFutx1Br0U36Kwa1UrvnxEI= Date: Wed, 15 Nov 2023 15:30:47 -0800 To: mm-commits@vger.kernel.org, willy@infradead.org, stable@vger.kernel.org, shy828301@gmail.com, riel@surriel.com, hannes@cmpxchg.org, david@redhat.com, shr@devkernel.io, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] mm-fix-for-negative-counter-nr_file_hugepages.patch removed from -mm tree Message-Id: <20231115233047.B5DF2C433C9@smtp.kernel.org> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The quilt patch titled Subject: mm: fix for negative counter: nr_file_hugepages has been removed from the -mm tree. Its filename was mm-fix-for-negative-counter-nr_file_hugepages.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Stefan Roesch Subject: mm: fix for negative counter: nr_file_hugepages Date: Mon, 6 Nov 2023 10:19:18 -0800 While qualifiying the 6.4 release, the following warning was detected in messages: vmstat_refresh: nr_file_hugepages -15664 The warning is caused by the incorrect updating of the NR_FILE_THPS counter in the function split_huge_page_to_list. The if case is checking for folio_test_swapbacked, but the else case is missing the check for folio_test_pmd_mappable. The other functions that manipulate the counter like __filemap_add_folio and filemap_unaccount_folio have the corresponding check. I have a test case, which reproduces the problem. It can be found here: https://github.com/sroeschus/testcase/blob/main/vmstat_refresh/madv.c The test case reproduces on an XFS filesystem. Running the same test case on a BTRFS filesystem does not reproduce the problem. AFAIK version 6.1 until 6.6 are affected by this problem. [akpm@linux-foundation.org: whitespace fix] [shr@devkernel.io: test for folio_test_pmd_mappable()] Link: https://lkml.kernel.org/r/20231108171517.2436103-1-shr@devkernel.io Link: https://lkml.kernel.org/r/20231106181918.1091043-1-shr@devkernel.io Signed-off-by: Stefan Roesch Co-debugged-by: Johannes Weiner Acked-by: Johannes Weiner Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: David Hildenbrand Reviewed-by: Yang Shi Cc: Rik van Riel Cc: Signed-off-by: Andrew Morton --- mm/huge_memory.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) --- a/mm/huge_memory.c~mm-fix-for-negative-counter-nr_file_hugepages +++ a/mm/huge_memory.c @@ -2769,13 +2769,15 @@ int split_huge_page_to_list(struct page int nr = folio_nr_pages(folio); xas_split(&xas, folio, folio_order(folio)); - if (folio_test_swapbacked(folio)) { - __lruvec_stat_mod_folio(folio, NR_SHMEM_THPS, - -nr); - } else { - __lruvec_stat_mod_folio(folio, NR_FILE_THPS, - -nr); - filemap_nr_thps_dec(mapping); + if (folio_test_pmd_mappable(folio)) { + if (folio_test_swapbacked(folio)) { + __lruvec_stat_mod_folio(folio, + NR_SHMEM_THPS, -nr); + } else { + __lruvec_stat_mod_folio(folio, + NR_FILE_THPS, -nr); + filemap_nr_thps_dec(mapping); + } } } _ Patches currently in -mm which might be from shr@devkernel.io are