From nobody Mon Feb 9 13:35:19 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 330DD279346 for ; Sun, 21 Dec 2025 08:58:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766307521; cv=none; b=HxlPfyxnbss/dkagIGF3RihDv6+2ul2cp8B+z2lc5YXEWE7Fs2hGjZ/MQDkMEKQIxjvedhIT/nPd9zG4vu4J+r9U1Gh7vQVbZzRWLOAHrHbg3iGWmDaZY0iych17y2YRyYeu0gncVLKIPpZGo3YbAljRZmaUvUBlFVXJKkSS5GU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766307521; c=relaxed/simple; bh=i+BuffpbQ1evWelb6BC39hX2PFwVeUN2Qm6SUzEdO50=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jdN1hflDVhwkHG1sQn02C5jZFuO2+xAh3RAZ0lvw5IyilMmt7ilXrnuXx9f1wJ3A86TxJwBhF0egjrbVjSzJahhBfI1J/TY/goKFQl0MBinVL/Jfw/Ym29bjZg4WaG6bAe0h+3Qxs3irOL3T+qZfcdBEdSjwULqG/zBmjnnlaPg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=N5vhLJeX; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="N5vhLJeX" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1766307518; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=W+AdUf+b21THrtxiV/+wgcurXGaYeTw1hKTQe5EVljM=; b=N5vhLJeXbGG5U6W36jYDX03PsicxWtPtq5tMKNa86C0nZpT2nCpxfz+KBhP4W9se73PazD q9FRaEh3GyZ4WrmOxspEhK5rRJtlvTST8LsXIrWfzAHKiIdEvZWcEJf8V0UAtiq3U2Ucd7 Lj7/RPfSd46/uHfwXMsLbLzcbpD2w6w= 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-315-1EQ6i2C-MaCOWXvOsRCSJg-1; Sun, 21 Dec 2025 03:58:32 -0500 X-MC-Unique: 1EQ6i2C-MaCOWXvOsRCSJg-1 X-Mimecast-MFC-AGG-ID: 1EQ6i2C-MaCOWXvOsRCSJg_1766307511 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 4A31E195608D; Sun, 21 Dec 2025 08:58:31 +0000 (UTC) Received: from dell-per7425-02.rhts.eng.pek2.redhat.com (dell-per7425-02.rhts.eng.pek2.redhat.com [10.73.116.18]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9937030001A2; Sun, 21 Dec 2025 08:58:27 +0000 (UTC) From: Li Wang To: akpm@linux-foundation.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: David Hildenbrand , Mark Brown , Shuah Khan , Waiman Long Subject: [PATCH v2 3/3] selftests/mm/charge_reserved_hugetlb: fix hugetlbfs mount size for large hugepages Date: Sun, 21 Dec 2025 16:58:10 +0800 Message-ID: <20251221085810.3163919-4-liwang@redhat.com> In-Reply-To: <20251221085810.3163919-1-liwang@redhat.com> References: <20251221085810.3163919-1-liwang@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Content-Type: text/plain; charset="utf-8" charge_reserved_hugetlb.sh mounts a hugetlbfs instance at /mnt/huge with a fixed size of 256M. On systems with large base hugepages (e.g. 512MB), this is smaller than a single hugepage, so the hugetlbfs mount ends up with effectively zero capacity (often visible as size=3D0 in mount output). As a result, write_to_hugetlbfs fails with ENOMEM and the test can hang waiting for progress. --- Error log --- # uname -r 6.12.0-xxx.el10.aarch64+64k #./charge_reserved_hugetlb.sh -cgroup-v2 # ----------------------------------------- ... # nr hugepages =3D 10 # writing cgroup limit: 5368709120 # writing reseravation limit: 5368709120 ... # write_to_hugetlbfs: Error mapping the file: Cannot allocate memory # Waiting for hugetlb memory reservation to reach size 2684354560. # 0 # Waiting for hugetlb memory reservation to reach size 2684354560. # 0 ... # mount |grep /mnt/huge none on /mnt/huge type hugetlbfs (rw,relatime,seclabel,pagesize=3D512M,si= ze=3D0) # grep -i huge /proc/meminfo ... HugePages_Total: 10 HugePages_Free: 10 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 524288 kB Hugetlb: 5242880 kB Mount hugetlbfs with size=3D${size}, the number of bytes the test will reserve/write, so the filesystem capacity is sufficient regardless of HugeTLB page size. Signed-off-by: Li Wang Cc: David Hildenbrand Cc: Mark Brown Cc: Shuah Khan Cc: Waiman Long --- tools/testing/selftests/mm/charge_reserved_hugetlb.sh | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh b/tools/= testing/selftests/mm/charge_reserved_hugetlb.sh index 249a5776c074..ac2744dbc0bd 100755 --- a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh +++ b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh @@ -295,7 +295,7 @@ function run_test() { setup_cgroup "hugetlb_cgroup_test" "$cgroup_limit" "$reservation_limit" =20 mkdir -p /mnt/huge - mount -t hugetlbfs -o pagesize=3D${MB}M,size=3D256M none /mnt/huge + mount -t hugetlbfs -o pagesize=3D${MB}M,size=3D${size} none /mnt/huge =20 write_hugetlbfs_and_get_usage "hugetlb_cgroup_test" "$size" "$populate" \ "$write" "/mnt/huge/test" "$method" "$private" "$expect_failure" \ @@ -349,7 +349,7 @@ function run_multiple_cgroup_test() { setup_cgroup "hugetlb_cgroup_test2" "$cgroup_limit2" "$reservation_limit= 2" =20 mkdir -p /mnt/huge - mount -t hugetlbfs -o pagesize=3D${MB}M,size=3D256M none /mnt/huge + mount -t hugetlbfs -o pagesize=3D${MB}M,size=3D${size} none /mnt/huge =20 write_hugetlbfs_and_get_usage "hugetlb_cgroup_test1" "$size1" \ "$populate1" "$write1" "/mnt/huge/test1" "$method" "$private" \ --=20 2.49.0