From patchwork Mon Nov 6 18:19:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 13447275 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 5A2C4C4332F for ; Mon, 6 Nov 2023 18:19:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C51606B026F; Mon, 6 Nov 2023 13:19:37 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C02606B0270; Mon, 6 Nov 2023 13:19:37 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AF16A6B0271; Mon, 6 Nov 2023 13:19:37 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id A15046B026F for ; Mon, 6 Nov 2023 13:19:37 -0500 (EST) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 687AE14089F for ; Mon, 6 Nov 2023 18:19:37 +0000 (UTC) X-FDA: 81428342394.30.7D95CE4 Received: from 66-220-144-179.mail-mxout.facebook.com (66-220-144-179.mail-mxout.facebook.com [66.220.144.179]) by imf28.hostedemail.com (Postfix) with ESMTP id DADE5C0013 for ; Mon, 6 Nov 2023 18:19:34 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=none; spf=neutral (imf28.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=1699294775; 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=tznUvWWUhmVDHsO88N8kkhvGkj2v84Ym28VkJnsQfv0=; b=zCvafErdHub90NoGxVHg9fQ40QE9uIlhhvKWp9b9eFGh0L+iXcPpAY5jKNo3ysrxuBdUZX fLA/VXtl+KTk0NJdXqqWuYb6xtG9IWT02i5Ghz5TRkWYXGlRD38k2RZATa1Yf12BXwYsAr MxRCfTEiz+zlMjspqLgShvHPewo4L8o= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=none; spf=neutral (imf28.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-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1699294775; a=rsa-sha256; cv=none; b=VKPjOGqG0hrridAk6Br/scV3eKSZbUBulU2Mlyxz0yoGPwK+S2yi3yYeY/VLLw2InK4yw2 Abm1Dru/q8LdFlRaap4Lt8z4Q1Pcr8wfRkjnu+j7otoe+6dXEcZ3WtK6sKo4yFy4xkzAVG I12KJ2pVGkgfR7cg3eAuw3t0vxtFoA8= Received: by devbig1114.prn1.facebook.com (Postfix, from userid 425415) id 9D200EE24BAF; Mon, 6 Nov 2023 10:19:19 -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 Subject: [PATCH v1] mm: Fix for negative counter: nr_file_hugepages Date: Mon, 6 Nov 2023 10:19:18 -0800 Message-Id: <20231106181918.1091043-1-shr@devkernel.io> X-Mailer: git-send-email 2.39.3 MIME-Version: 1.0 X-Rspamd-Queue-Id: DADE5C0013 X-Rspam-User: X-Stat-Signature: fm9ifhz9bbkkm7rnqirw9sz7zppn9utt X-Rspamd-Server: rspam01 X-HE-Tag: 1699294774-658559 X-HE-Meta: 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 cT6pX8rN d0s7mKyEtKL57g8VrPAXqQdLWTxdF5MQmN7q7XCgt6T336f65MDrm7rl65SnEd8o2+7E3z9/0Y/4lqMMZBQLvcRcqvWoE+oUbOZNZWVPAZ5F9YUheVpsZ9Sl4xtDvz/GKX/5Rejur4gm2C7t8TECGfLkE/Q== 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 | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) base-commit: ffc253263a1375a65fa6c9f62a893e9767fbebfa diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 064fbd90822b4..ea6bee675c4d3 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2740,7 +2740,8 @@ 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);