From nobody Wed Dec 17 08:00:50 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4802CDB47E for ; Fri, 13 Oct 2023 09:38:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231246AbjJMJiO (ORCPT ); Fri, 13 Oct 2023 05:38:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230512AbjJMJiI (ORCPT ); Fri, 13 Oct 2023 05:38:08 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 578BEBE; Fri, 13 Oct 2023 02:38:05 -0700 (PDT) Date: Fri, 13 Oct 2023 09:38:03 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1697189884; 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: in-reply-to:in-reply-to:references:references; bh=wvykBSg8m0Q1xA5BZ7F/jqR4FIzxpwGYfb6UZQ016/0=; b=ogvC0Ii/A9JdjRoEHABoWKkyShDYaPc6kHMKTT/4OTwqcqpExBdwp+81MTazfcyBl+IkHQ +dIGwD9FHRRsFsAM+6DthQphJ9lbKGXl/rHpLFqmptKnWZwmy8NdvsL4kPuuV4FKEjDYmS p4lySpLg/OMJ8TD3hCoWuyMChKxU53NwI5sI7YIzOwBzpXMZgYE35+coITUupiP08nvXX0 O1IskfDTe85xAqjCXd1jMJxSnB4fBidyrxLWs3DHNzTmC+FHOtdBL22Og9qicW5j5ewRig MAWadzl/QIKHuf6CuIa7cmDhetN49MerldxbQvq3FXHVo9Ow/XncerAiaf2Teg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1697189884; 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: in-reply-to:in-reply-to:references:references; bh=wvykBSg8m0Q1xA5BZ7F/jqR4FIzxpwGYfb6UZQ016/0=; b=oGPC7omCb1GCJMaFBZRaNSfZ40MYbe4OYx3trhbjMcCGHSHtQHC7LsKz7lkf4lkS2kP9os O9icP0JcxM3zm+Dg== From: "tip-bot2 for Thomas Gleixner" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/core] x86/cpu/topology: Cure the abuse of cpuinfo for persisting logical ids Cc: Thomas Gleixner , Juergen Gross , Sohil Mehta , Michael Kelley , "Peter Zijlstra (Intel)" , Zhang Rui , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20230814085113.292947071@linutronix.de> References: <20230814085113.292947071@linutronix.de> MIME-Version: 1.0 Message-ID: <169718988316.3135.12947465467392664307.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/core branch of tip: Commit-ID: 90781f0c4c41a41043e39d9acbc66cc3644769ba Gitweb: https://git.kernel.org/tip/90781f0c4c41a41043e39d9acbc66cc36= 44769ba Author: Thomas Gleixner AuthorDate: Mon, 14 Aug 2023 10:18:46 +02:00 Committer: Thomas Gleixner CommitterDate: Tue, 10 Oct 2023 14:38:19 +02:00 x86/cpu/topology: Cure the abuse of cpuinfo for persisting logical ids Per CPU cpuinfo is used to persist the logical package and die IDs. That's really not the right place simply because cpuinfo is subject to be reinitialized when a CPU goes through an offline/online cycle. This works by chance today, but that's far from correct and neither obvious nor documented. Add a per cpu datastructure which persists those logical IDs, which allows to cleanup the CPUID evaluation code. This is a temporary workaround until the larger topology management is in place, which makes all of this logical management mechanics obsolete. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Sohil Mehta Tested-by: Michael Kelley Tested-by: Peter Zijlstra (Intel) Tested-by: Zhang Rui Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20230814085113.292947071@linutronix.de --- arch/x86/kernel/smpboot.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 04a1136..54541a1 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -124,7 +124,20 @@ struct mwait_cpu_dead { */ static DEFINE_PER_CPU_ALIGNED(struct mwait_cpu_dead, mwait_cpu_dead); =20 -/* Logical package management. We might want to allocate that dynamically = */ +/* Logical package management. */ +struct logical_maps { + u32 phys_pkg_id; + u32 phys_die_id; + u32 logical_pkg_id; + u32 logical_die_id; +}; + +/* Temporary workaround until the full topology mechanics is in place */ +static DEFINE_PER_CPU_READ_MOSTLY(struct logical_maps, logical_maps) =3D { + .phys_pkg_id =3D U32_MAX, + .phys_die_id =3D U32_MAX, +}; + unsigned int __max_logical_packages __read_mostly; EXPORT_SYMBOL(__max_logical_packages); static unsigned int logical_packages __read_mostly; @@ -337,10 +350,8 @@ int topology_phys_to_logical_pkg(unsigned int phys_pkg) int cpu; =20 for_each_possible_cpu(cpu) { - struct cpuinfo_x86 *c =3D &cpu_data(cpu); - - if (c->initialized && c->topo.pkg_id =3D=3D phys_pkg) - return c->topo.logical_pkg_id; + if (per_cpu(logical_maps.phys_pkg_id, cpu) =3D=3D phys_pkg) + return per_cpu(logical_maps.logical_pkg_id, cpu); } return -1; } @@ -358,11 +369,9 @@ static int topology_phys_to_logical_die(unsigned int d= ie_id, unsigned int cur_cp int cpu, proc_id =3D cpu_data(cur_cpu).topo.pkg_id; =20 for_each_possible_cpu(cpu) { - struct cpuinfo_x86 *c =3D &cpu_data(cpu); - - if (c->initialized && c->topo.die_id =3D=3D die_id && - c->topo.pkg_id =3D=3D proc_id) - return c->topo.logical_die_id; + if (per_cpu(logical_maps.phys_pkg_id, cpu) =3D=3D proc_id && + per_cpu(logical_maps.phys_die_id, cpu) =3D=3D die_id) + return per_cpu(logical_maps.logical_die_id, cpu); } return -1; } @@ -387,6 +396,8 @@ int topology_update_package_map(unsigned int pkg, unsig= ned int cpu) cpu, pkg, new); } found: + per_cpu(logical_maps.phys_pkg_id, cpu) =3D pkg; + per_cpu(logical_maps.logical_pkg_id, cpu) =3D new; cpu_data(cpu).topo.logical_pkg_id =3D new; return 0; } @@ -410,6 +421,8 @@ int topology_update_die_map(unsigned int die, unsigned = int cpu) cpu, die, new); } found: + per_cpu(logical_maps.phys_die_id, cpu) =3D die; + per_cpu(logical_maps.logical_die_id, cpu) =3D new; cpu_data(cpu).topo.logical_die_id =3D new; return 0; }