From patchwork Tue Nov 7 18:18:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13449181 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id BC033C4332F for ; Tue, 7 Nov 2023 18:18:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3A9CE900002; Tue, 7 Nov 2023 13:18:29 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3591B8D0001; Tue, 7 Nov 2023 13:18:29 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 24797900002; Tue, 7 Nov 2023 13:18:29 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 16A768D0001 for ; Tue, 7 Nov 2023 13:18:29 -0500 (EST) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id DE3B0B5C37 for ; Tue, 7 Nov 2023 18:18:28 +0000 (UTC) X-FDA: 81431968296.30.32F4905 Received: from 66-220-144-179.mail-mxout.facebook.com (66-220-144-179.mail-mxout.facebook.com [66.220.144.179]) by imf18.hostedemail.com (Postfix) with ESMTP id 541E21C0005 for ; Tue, 7 Nov 2023 18:18:27 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=none; spf=neutral (imf18.hostedemail.com: 66.220.144.179 is neither permitted nor denied by domain of shr@devkernel.io) smtp.mailfrom=shr@devkernel.io; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1699381107; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:references; bh=27lZBsjz2S5mUUmZG7RU4YbWyzqaEVupahO80UQSBqU=; b=SpIchkYd8MVRoDBCen7KGQJn3Rw0KxPhZCaAUfI0YyVqExAAiBez6clLwGm2ubX6TLYLpu B+EV8qEmrN5s4rUYm0mbVr+393r8IdnTIxQlMpY0LBkNhiSPVtCkmcwQhvASir5jvazQNf BQh6ERktiRbJlOlqFs80huAMCwGhbno= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1699381107; a=rsa-sha256; cv=none; b=cd5FSg1lLbg4FHfNaPBsDIg8YGWpzD3I6l228P6Jc3YTYYU5fEqCwXxdGFfNcCiWWS9hdk 0361lfpqB8t/IKyX1hZD5Vy5ILGW8jF8F26M8O+FfgfIpfQW0xukcSmAc2Xcb9RI9MgR9Y pa3a2+Cgur3jYSeNv7D3g+i445gc4Jk= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=none; spf=neutral (imf18.hostedemail.com: 66.220.144.179 is neither permitted nor denied by domain of shr@devkernel.io) smtp.mailfrom=shr@devkernel.io; dmarc=none Received: by devbig1114.prn1.facebook.com (Postfix, from userid 425415) id 51DF9EF0641B; Tue, 7 Nov 2023 10:18:12 -0800 (PST) From: Stefan Roesch To: kernel-team@fb.com Cc: shr@devkernel.io, akpm@linux-foundation.org, hannes@cmpxchg.org, riel@surriel.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org Subject: [PATCH v2] mm: Fix for negative counter: nr_file_hugepages Date: Tue, 7 Nov 2023 10:18:05 -0800 Message-Id: <20231107181805.4188397-1-shr@devkernel.io> X-Mailer: git-send-email 2.39.3 MIME-Version: 1.0 X-Rspamd-Queue-Id: 541E21C0005 X-Rspam-User: X-Stat-Signature: kyeag48fgrwkwjsork3jmpygw4pm4qbh X-Rspamd-Server: rspam03 X-HE-Tag: 1699381107-230552 X-HE-Meta: U2FsdGVkX1/Kb9ZBe7FYHtVYsFGjl2QgzJyjym9Jw2h1F7mRgUoesOBr1c5V3tfl82BSYEc4rFUnRY66gupGCxY9w2FP4r0u69vDj6Ptl9damhREbviFAO9N/wq4/cJXbMIR17kmvQF8hTTFYZbY3Nfp/0LU3fDGOce/XnlgaVsErPWtMDgXuc6uiDUtiH2lId1SHUkeUN+Ai6bt9WKy1SyJefygOYap0uZdlCeHKheGFmvhnQRfdrCaR2Pe3X00ryXphNsog8bMP5QLYXnMXpdzSShzCeK5fD/AbOZuzt+yeX5ZqFJsBpFexYZ0D4TEtnR7PrLLy/ItdJ0WwCm13kBArDdaijKC0mELabKqeJXwzUUhzawePswWvEBNodhg08rCNzQai9ERIXNjrjxN+QO9eLaID/ufqsLdSHv4Ke4FN7AQ0EuLkhDXxAlVS+7S64O7OwW6uwY6gkeYJWeF/nTsX4GxyWgJb1qZ0VKu4t0GntXDJoizTdPvGMWIkJxJrv5U77FqMom5ggyiwfepqAm08dBY97QoNg+0eQlkk2HCXY6RejY+IhWtp+0QUBt0JDlJqYd8B76Q7pPQ1N1sNlj2YQiahzSRHV1zkDEImGEBqtyL5iJUvJYpYcsr3+m8EbCwN17HlLuvJkC6sjHveMu1PCN4N2qUZ9USq/WQdaBnO/jqcWWvyJGfqlPbEnD6wSZ0SI4K9109ClE3pjRW9XaJ4aOVWLzOGKE3b1XSvfZHxU//hysBaHWfKWfoeoTtKFAkVfi63JnTqtldhBnmCbnYp4U8Bf3wkPvDQm52LGLujC7Lx+J92TSZ3RSt0hTcvfwRQGPXGWSLE42B6UoiMZHE64gd3utasvks0/Ax/4jAdt1YS7ekbxixwYzPXfmhiZs5IkgCnHkjVoUoiDqlJoX/a8wKO7BIxVWZG6Sw1zh2BXQaUYofCmSB9LtnDpgavI4KknF6oi2aeUJg+pc L3Sl/s0h 4RWLy+1eYPAGL6pcDgYlFn8UeMoQRb6MYl5vfQuFZR2r91AbmNbqzpg31p9GThCj5OTcRPD9+3B+SdgkjX11iYnltEvUyiyUBGWAdMbFLZvFU2/BVxFws1UlF9Zpglk2XnANlP855bUhdhObOxrL0O1Wv7Q== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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. Signed-off-by: Stefan Roesch Co-debugged-by: Johannes Weiner Acked-by: Johannes Weiner --- mm/huge_memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) base-commit: ffc253263a1375a65fa6c9f62a893e9767fbebfa diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 064fbd90822b4..9dbd5ef5a3902 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2740,7 +2740,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) if (folio_test_swapbacked(folio)) { __lruvec_stat_mod_folio(folio, NR_SHMEM_THPS, -nr); - } else { + } else if (folio_test_pmd_mappable(folio)) { __lruvec_stat_mod_folio(folio, NR_FILE_THPS, -nr); filemap_nr_thps_dec(mapping);