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 71C40E94615 for ; Mon, 9 Feb 2026 22:15:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D5CAF6B0095; Mon, 9 Feb 2026 17:15:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CE73D6B00A0; Mon, 9 Feb 2026 17:15:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BFBD56B00A2; Mon, 9 Feb 2026 17:15:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 9C8A36B0095 for ; Mon, 9 Feb 2026 17:15:15 -0500 (EST) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 3C4DC1A0312 for ; Mon, 9 Feb 2026 22:15:15 +0000 (UTC) X-FDA: 84426324990.15.CC24DC1 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf04.hostedemail.com (Postfix) with ESMTP id 7BAAF40010 for ; Mon, 9 Feb 2026 22:15:13 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=d37FRF9G; dmarc=pass (policy=quarantine) header.from=redhat.com; spf=pass (imf04.hostedemail.com: domain of luizcap@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=luizcap@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1770675313; a=rsa-sha256; cv=none; b=pwgxAg5kWJaWXSQDrySvtnWZsxWfGVxjRUPEl802uVr6eiODvcZVLE4k5OeEH1dzW2ic9E gRKtUgsc1JYp2pc/yc2FCBvFVHJuV3jWiRZlY3yYcq7+E4knF/vAXtfFp8bMq0hyNdxT/s FWkmSsNWn+9jytQxEn+R7vyM2DEwtII= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=d37FRF9G; dmarc=pass (policy=quarantine) header.from=redhat.com; spf=pass (imf04.hostedemail.com: domain of luizcap@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=luizcap@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1770675313; 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=+HpD3amJN83e1nK4/UYx8PNBs97+doRf6FtLNeMX5c0=; b=agWqqVo1miYUQ3EM0CqmEC3q8N20YytbO50rodjsxryepZDPhHi0ys4TBcnSCmUxWbnlPN 54aX9RYT6Z8Lg4A+DfrtlQAByyqA4U7a4YhDhMF+8szLoYLe8GPWw/fsmB16LPpqpXjhyE QdJHP8NorbTrNUp+oPGiA49VXvCiGa8= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1770675312; 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=+HpD3amJN83e1nK4/UYx8PNBs97+doRf6FtLNeMX5c0=; b=d37FRF9GcECnTk+9C6rc+URbutXcomtNXKla10FG/8cwKYbn++DGPyE/0WopKNsNAfooID BQS9PFXmrgAbbLdiEFQYC5l2LS3dSYRExeV+UTX/2WQPzX2EuSdMMkq3nmjHOpeG5dan7w 3+5Nnx+8REGGTvsUJf6XN7KO6/NNvck= Received: from mx-prod-mc-03.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-446-_cUmsVACN5G5gKmJRBu_YA-1; Mon, 09 Feb 2026 17:15:02 -0500 X-MC-Unique: _cUmsVACN5G5gKmJRBu_YA-1 X-Mimecast-MFC-AGG-ID: _cUmsVACN5G5gKmJRBu_YA_1770675301 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E4D961955F12; Mon, 9 Feb 2026 22:15:00 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.22.65.66]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 47B0818003F6; Mon, 9 Feb 2026 22:14:59 +0000 (UTC) From: Luiz Capitulino To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, david@kernel.org, baolin.wang@linux.alibaba.com Cc: ryan.roberts@arm.com, akpm@linux-foundation.org, lorenzo.stoakes@oracle.com Subject: [PATCH v2 10/11] mm: thp: always enable mTHP support Date: Mon, 9 Feb 2026 17:14:32 -0500 Message-ID: <29e8dfc2772af4b6e0db24134ca3563ec422b91a.1770675272.git.luizcap@redhat.com> In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 X-Mimecast-MFC-PROC-ID: qFq6FwIpehykfrWikrdCLrMTlZlR-9AOp--MRCDNbVI_1770675301 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit content-type: text/plain; charset="US-ASCII"; x-default=true X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 7BAAF40010 X-Stat-Signature: xtxkw7amqdgb57a6wwxiy1zpybo4zhfh X-HE-Tag: 1770675313-505806 X-HE-Meta: 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 NOSAoBN/ cOwfB8YGXoiSqrh4= 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: If PMD-sized pages are not supported on an architecture (ie. the arch implements arch_has_pmd_leaves() and it returns false) then the current code disables all THP, including mTHP. This commit fixes this by allowing mTHP to be always enabled for all archs. When PMD-sized pages are not supported, its sysfs entry won't be created and their mapping will be disallowed at page-fault time. Similarly, this commit implements the following changes for shmem: - In shmem_allowable_huge_orders(): drop the pgtable_has_pmd_leaves() check so that mTHP sizes are considered - In shmem_alloc_and_add_folio(): don't consider PMD and PUD orders when PMD-sized pages are not supported by the CPU Signed-off-by: Luiz Capitulino --- mm/huge_memory.c | 11 +++++++---- mm/shmem.c | 4 +++- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 1e5ea2e47f79..882331592928 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -115,6 +115,9 @@ unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma, else supported_orders = THP_ORDERS_ALL_FILE_DEFAULT; + if (!pgtable_has_pmd_leaves()) + supported_orders &= ~(BIT(PMD_ORDER) | BIT(PUD_ORDER)); + orders &= supported_orders; if (!orders) return 0; @@ -122,7 +125,7 @@ unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma, if (!vma->vm_mm) /* vdso */ return 0; - if (!pgtable_has_pmd_leaves() || vma_thp_disabled(vma, vm_flags, forced_collapse)) + if (vma_thp_disabled(vma, vm_flags, forced_collapse)) return 0; /* khugepaged doesn't collapse DAX vma, but page fault is fine. */ @@ -806,6 +809,9 @@ static int __init hugepage_init_sysfs(struct kobject **hugepage_kobj) } orders = THP_ORDERS_ALL_ANON | THP_ORDERS_ALL_FILE_DEFAULT; + if (!pgtable_has_pmd_leaves()) + orders &= ~(BIT(PMD_ORDER) | BIT(PUD_ORDER)); + order = highest_order(orders); while (orders) { thpsize = thpsize_create(order, *hugepage_kobj); @@ -905,9 +911,6 @@ static int __init hugepage_init(void) int err; struct kobject *hugepage_kobj; - if (!pgtable_has_pmd_leaves()) - return -EINVAL; - /* * hugepages can't be allocated by the buddy allocator */ diff --git a/mm/shmem.c b/mm/shmem.c index 1c98e84667a4..cb325d1e2d1e 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1827,7 +1827,7 @@ unsigned long shmem_allowable_huge_orders(struct inode *inode, vm_flags_t vm_flags = vma ? vma->vm_flags : 0; unsigned int global_orders; - if (!pgtable_has_pmd_leaves() || (vma && vma_thp_disabled(vma, vm_flags, shmem_huge_force))) + if (vma && vma_thp_disabled(vma, vm_flags, shmem_huge_force)) return 0; global_orders = shmem_huge_global_enabled(inode, index, write_end, @@ -1935,6 +1935,8 @@ static struct folio *shmem_alloc_and_add_folio(struct vm_fault *vmf, if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) orders = 0; + else if (!pgtable_has_pmd_leaves()) + orders &= ~(BIT(PMD_ORDER) | BIT(PUD_ORDER)); if (orders > 0) { suitable_orders = shmem_suitable_orders(inode, vmf, -- 2.53.0