From nobody Mon Feb 9 17:58:45 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 3358F1EB1BF; Thu, 17 Apr 2025 18:03:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744913009; cv=none; b=tLDDjgWoSV28qYC36oGec+413ba1LyY7IbyJJRwmEIeAfOQdnETyd9tej4nzUu2t/OE7vhZWv0DgaYcA+jYOz/Ngs4AE3eDKhqoDL2Dox164md1s/yRIwm93CVQc2s7H9vA4VTVWU1YKtutHuxvVAP4FfXfGuR8H2fFcGaRVkwI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744913009; c=relaxed/simple; bh=xPztG5wmdGiJK341Tf8Fn890tlmGDPg15aKO2BJHYaE=; h=Date:From:To:Subject:Cc:MIME-Version:Message-ID:Content-Type; b=gHZcmOQ/VJbt3JI1gyDibp+n/QHX37oss+uboN34oTPUHPrAsyWXZJS3IPiYnTDAMWPlsA39eGylom5VeMiL+FE37YtDF6n1DT7W0uNWQ6W4TZX1m2lQkTKQ/+GZYJ31wsVFq+He7m8scp7IVhWWWdA/4vBsODo5Lc5nJ7yKPME= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=MVGD7xjF; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=rbuVZ9Vl; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="MVGD7xjF"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="rbuVZ9Vl" Date: Thu, 17 Apr 2025 18:03:24 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1744913006; h=from:from:sender:sender:reply-to: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; bh=uhEx+dFtU5a+nA+flpSZ6OqqcO6apZEwjUbR4CHkMUI=; b=MVGD7xjFUQ5qRNujvy2LzYhZu8AcG7TRVomoZhGdTSWYmR/nlkY1qtj/2u1eLD5I7/xo5Y ZV286W42fm1BH/SsHcPYJJDWG9UuEhruC/Q7crJJzRvtNEJloAL4Haqp4H38jdw72U2olN YqXr5sTLLriLLOZRrpLEuFyK45fz2KhZZgYNMZKClahXn8jOS/+9ouHbaa17YzXtF6eUGJ a0o83B/bRGG7TP8acEYSYeQp7nb2Y6l0VGBNvbSvUHJ3RjoZXW/gI8cYHzDNcaWI//9Mvp kbBzdjiuX9vEYPHiQ5Xz0bc+N0XzEMN7V626nh99hSp1TYJCS1K82AP/QOyHjw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1744913006; h=from:from:sender:sender:reply-to: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; bh=uhEx+dFtU5a+nA+flpSZ6OqqcO6apZEwjUbR4CHkMUI=; b=rbuVZ9Vl0MjvhCMZsxzbClAHC7JQ9rTw3CRwLiD4m3WuPDT5QPJQuerPYPDKcTYFOATCSl olbqwiy7yL2mUQCw== From: "tip-bot2 for Dave Hansen" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/mm] x86/mm: Preallocate all PAE page tables Cc: Dave Hansen , x86@kernel.org, linux-kernel@vger.kernel.org Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <174491300499.31282.12749824705521273948.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the x86/mm branch of tip: Commit-ID: 454e65b4fb38ddeea62472649ef16b5e8d285015 Gitweb: https://git.kernel.org/tip/454e65b4fb38ddeea62472649ef16b5e8= d285015 Author: Dave Hansen AuthorDate: Mon, 14 Apr 2025 10:32:41 -07:00 Committer: Dave Hansen CommitterDate: Thu, 17 Apr 2025 10:39:25 -07:00 x86/mm: Preallocate all PAE page tables Finally, move away from having PAE kernels share any PMDs across processes. This was already the default on PTI kernels which are the common case. Signed-off-by: Dave Hansen Link: https://lore.kernel.org/all/20250414173241.1288CAB4%40davehans-spike.= ostc.intel.com --- arch/x86/mm/pgtable.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index ca07db5..f4fa8fa 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -80,16 +80,11 @@ struct mm_struct *pgd_page_get_mm(struct page *page) =20 static void pgd_ctor(struct mm_struct *mm, pgd_t *pgd) { - /* If the pgd points to a shared pagetable level (either the - ptes in non-PAE, or shared PMD in PAE), then just copy the - references from swapper_pg_dir. */ - if (CONFIG_PGTABLE_LEVELS =3D=3D 2 || - (CONFIG_PGTABLE_LEVELS =3D=3D 3 && SHARED_KERNEL_PMD) || - CONFIG_PGTABLE_LEVELS >=3D 4) { + /* PAE preallocates all its PMDs. No cloning needed. */ + if (!IS_ENABLED(CONFIG_X86_PAE)) clone_pgd_range(pgd + KERNEL_PGD_BOUNDARY, swapper_pg_dir + KERNEL_PGD_BOUNDARY, KERNEL_PGD_PTRS); - } =20 /* List used to sync kernel mapping updates */ pgd_set_mm(pgd, mm); @@ -122,8 +117,7 @@ static void pgd_dtor(pgd_t *pgd) * all 4 top-level entries are used almost immediately in a * new process's life, we just pre-populate them here. */ -#define PREALLOCATED_PMDS (static_cpu_has(X86_FEATURE_PTI) ? \ - PTRS_PER_PGD : KERNEL_PGD_BOUNDARY) +#define PREALLOCATED_PMDS PTRS_PER_PGD #define MAX_PREALLOCATED_PMDS PTRS_PER_PGD =20 /*