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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8A74AC43602 for ; Fri, 3 Jul 2026 00:32:39 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E140B6B00D4; Thu, 2 Jul 2026 20:32:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DEC096B00D7; Thu, 2 Jul 2026 20:32:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CDAA96B00D8; Thu, 2 Jul 2026 20:32:37 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 92ED36B00D4 for ; Thu, 2 Jul 2026 20:32:37 -0400 (EDT) Received: from smtpin09.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay07.hostedemail.com (Postfix) with ESMTP id C97DA16789A for ; Thu, 2 Jul 2026 17:25:30 +0000 (UTC) X-FDA: 84944513220.09.B2FB562 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf30.hostedemail.com (Postfix) with ESMTP id D9EC980009 for ; Thu, 2 Jul 2026 17:25:28 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="JT/KkjPI"; spf=pass (imf30.hostedemail.com: domain of npache@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=npache@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1783013129; b=8UqPn3Uo7M+i0MKa3sEPSTUuzjonNFDSA7db84OjrC3AfSXxXcN78H9bQtkA61sJnp+NoG QJO2hdXXTs+UojWE046dXxMdWbf5k8cW5+aI2uSuEbQI99j9Qvwa2F3c2+NDJHStHM+zo4 qRX9EWhpnhp4B7C5ojarXLl/lhBxCuA= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1783013129; 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-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=cBefviiafkFbe/nsc/cyLo5CV934Kk6BkNirD8bq4mc=; b=QlDYawJkf4h5z8eq3ApPYIf1KIqR5rryjxQiOl27zs2vnPC3C8uNHlg7LPR8wyGuEGYdMS p+SexKHqVm12rctlPodaYeqTxB7GyHH7YlWFOg5GbOTdxfYZopov9id+j3j1E/ZtH/Ufly hRLGcRKBTzfplBWLfJKRkWreuQ+9sS4= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="JT/KkjPI"; spf=pass (imf30.hostedemail.com: domain of npache@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=npache@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1783013128; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cBefviiafkFbe/nsc/cyLo5CV934Kk6BkNirD8bq4mc=; b=JT/KkjPIlbroq5pf5LRyfYXwKp1BWiW2eVA6PY4uphi5DTMKe2Vz0V1F5Pxt2RvVk9N+hT l3BdP2LYy68XPOC36lEXpITDhcbgGAMSSwSCi0wa/EC9us6dV+NDJttEnkJOrfXYUHvYRn 04AUNKXPXNvaME2P4KfTnCvV3KZ3/dA= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-8-YlzfNNoRPHuWMl6LqaNVfA-1; Thu, 02 Jul 2026 13:25:22 -0400 X-MC-Unique: YlzfNNoRPHuWMl6LqaNVfA-1 X-Mimecast-MFC-AGG-ID: YlzfNNoRPHuWMl6LqaNVfA_1783013120 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 950071944CF2; Thu, 2 Jul 2026 17:25:19 +0000 (UTC) Received: from p1.redhat.com (unknown [10.22.76.7]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 4486E30030D0; Thu, 2 Jul 2026 17:25:10 +0000 (UTC) From: Nico Pache To: Barry Song , David Hildenbrand , linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: ljs@kernel.org, willy@infradead.org, Nico Pache , Oscar Salvador , Andrew Morton , Zi Yan , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple Subject: [PATCH 2/2] mm/migrate: exclude hugetlb folios from MTHP_STAT_NR_ANON accounting Date: Thu, 2 Jul 2026 11:25:47 -0600 Message-ID: <20260702172548.37075-3-npache@redhat.com> In-Reply-To: <20260702172548.37075-1-npache@redhat.com> References: <20260702172548.37075-1-npache@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 X-Mimecast-MFC-PROC-ID: tyBEfGF2aRTUIU3lYGCSJz5HvXLEDneWgHM0oKiaoP0_1783013120 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Stat-Signature: enrxntdp6ksofpc3qozc8meegqw85dbh X-Rspam-User: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: D9EC980009 X-HE-Tag: 1783013128-557617 X-HE-Meta: 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 NPcbRWSx E0yqEyyTr53Fq3iX1yXKNSm5gyOd2zkmtXIQACmedpmu93CENRnGxk4JPeU3sPR5xRNxMeCVa35eqeYVA5P3/10TwQspnWH3dDM+lJ74PxKSDkAYLbbAylALaOrS0Hv6PQWdNyqiz94yY5Tdzwbe9s5hr4uazpAJ5rhQW96GrrkR+kcz47SOzuHmddE+MwzOA+lf63csA265mhvmed45/9wtrQVE79VRaoVK7hgl7MLg44o4f4+oyaVlb/MZSdBbH6Txl60h/3ohQ4Ex3uGDWpkDaXTnY0K6LVWzOVh5S4nYzZmbhEF7xiU6BbHgEuuhxOal2vR22Jr49ieKZjkY2c9o36j+wdZn776FE86hP8pB/2CPB4k7NOYmA2IyvD8bC/KJ+T4KjtrjQQw7tvtDnB3I0fROIfhk9wCKPI01RdR7zYU3mM2lLz0Uez6gDZAqUaDJH7k6CmutXFuRIHvEnsTQICnE00QNBOl0w+yx9R6k2GZ0= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: __folio_migrate_mapping() increments MTHP_STAT_NR_ANON for the destination folio when `folio_test_anon(folio) && folio_test_large(folio)` is true. However, hugetlb folios satisfy both conditions despite having a completely separate accounting system; they use hugetlb_add_anon_rmap() which does not touch mTHP stats, and their free path also bypasses the mTHP decrement in __free_pages_prepare(). This causes MTHP_STAT_NR_ANON to be incremented on each hugetlb migration without a corresponding decrement, permanently inflating the nr_anon counter. Add a !folio_test_hugetlb() check to both places in __folio_migrate_mapping() so that only actual mTHP folios are counted. Fixes: 5d65c8d758f2 ("mm: count the number of anonymous THPs per size") Co-developed-by: David Hildenbrand Signed-off-by: David Hildenbrand Signed-off-by: Nico Pache --- mm/migrate.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index d9b23909d716..9fd50ea25d2d 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -590,7 +590,8 @@ static int __folio_migrate_mapping(struct address_space *mapping, /* No turning back from here */ newfolio->index = folio->index; newfolio->mapping = folio->mapping; - if (folio_test_anon(folio) && folio_test_large(folio)) + if (folio_test_anon(folio) && folio_test_large(folio) && + !folio_test_hugetlb(folio)) mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON, 1); if (folio_test_swapbacked(folio)) __folio_set_swapbacked(newfolio); @@ -623,7 +624,8 @@ static int __folio_migrate_mapping(struct address_space *mapping, */ newfolio->index = folio->index; newfolio->mapping = folio->mapping; - if (folio_test_anon(folio) && folio_test_large(folio)) + if (folio_test_anon(folio) && folio_test_large(folio) && + !folio_test_hugetlb(folio)) mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON, 1); folio_ref_add(newfolio, nr); /* add cache reference */ if (folio_test_swapbacked(folio)) -- 2.54.0