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 X-Spam-Level: X-Spam-Status: No, score=-12.0 required=3.0 tests=BAYES_00,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B2AAC4361B for ; Tue, 8 Dec 2020 13:29:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 561FD23ACA for ; Tue, 8 Dec 2020 13:29:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729020AbgLHN33 (ORCPT ); Tue, 8 Dec 2020 08:29:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:47824 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726080AbgLHN33 (ORCPT ); Tue, 8 Dec 2020 08:29:29 -0500 From: Will Deacon Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Will Deacon , Catalin Marinas , Marc Zyngier , Greg Kroah-Hartman , Peter Zijlstra , Morten Rasmussen , Qais Yousef , Suren Baghdasaryan , Quentin Perret , Tejun Heo , Li Zefan , Johannes Weiner , Ingo Molnar , Juri Lelli , Vincent Guittot , kernel-team@android.com Subject: [PATCH v5 00/15] An alternative series for asymmetric AArch32 systems Date: Tue, 8 Dec 2020 13:28:20 +0000 Message-Id: <20201208132835.6151-1-will@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, Christmas has come early: it's time for version five of these patches which have previously appeared here: v1: https://lore.kernel.org/r/20201027215118.27003-1-will@kernel.org v2: https://lore.kernel.org/r/20201109213023.15092-1-will@kernel.org v3: https://lore.kernel.org/r/20201113093720.21106-1-will@kernel.org v4: https://lore.kernel.org/r/20201124155039.13804-1-will@kernel.org and which started life as a reimplementation of some patches from Qais: https://lore.kernel.org/r/20201021104611.2744565-1-qais.yousef@arm.com There's also now a nice writeup on LWN: https://lwn.net/Articles/838339/ and rumours of a feature film are doing the rounds. [subscriber-only, but if you're reading this then you should really subscribe.] The aim of this series is to allow 32-bit ARM applications to run on arm64 SoCs where not all of the CPUs support the 32-bit instruction set. Unfortunately, such SoCs are real and will continue to be productised over the next few years at least. I can assure you that I'm not just doing this for fun. Changes in v5 include: * Teach cpuset_cpus_allowed() about task_cpu_possible_mask() so that we can avoid returning incompatible CPUs for a given task. This means that sched_setaffinity() can be used with larger masks (like the online mask) from userspace and also allows us to take into account the cpuset hierarchy when forcefully overriding the affinity for a task on execve(). * Honour task_cpu_possible_mask() when attaching a task to a cpuset, so that the resulting affinity mask does not contain any incompatible CPUs (since it would be rejected by set_cpus_allowed_ptr() otherwise). * Moved overriding of the affinity mask into the scheduler core rather than munge affinity masks directly in the architecture backend. * Extended comments and documentation. * Some renaming and cosmetic changes. I'm pretty happy with this now, although it still needs review and will require rebasing to play nicely with the SCA changes in -next. Cheers, Will Cc: Catalin Marinas Cc: Marc Zyngier Cc: Greg Kroah-Hartman Cc: Peter Zijlstra Cc: Morten Rasmussen Cc: Qais Yousef Cc: Suren Baghdasaryan Cc: Quentin Perret Cc: Tejun Heo Cc: Li Zefan Cc: Johannes Weiner Cc: Ingo Molnar Cc: Juri Lelli Cc: Vincent Guittot Cc: kernel-team@android.com --->8 Will Deacon (15): arm64: cpuinfo: Split AArch32 registers out into a separate struct arm64: Allow mismatched 32-bit EL0 support KVM: arm64: Kill 32-bit vCPUs on systems with mismatched EL0 support arm64: Kill 32-bit applications scheduled on 64-bit-only CPUs arm64: Advertise CPUs capable of running 32-bit applications in sysfs sched: Introduce task_cpu_possible_mask() to limit fallback rq selection cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1 cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus() sched: Reject CPU affinity changes based on task_cpu_possible_mask() sched: Introduce force_compatible_cpus_allowed_ptr() to limit CPU affinity arm64: Implement task_cpu_possible_mask() arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0 arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores .../ABI/testing/sysfs-devices-system-cpu | 9 + .../admin-guide/kernel-parameters.txt | 8 + arch/arm64/include/asm/cpu.h | 44 ++-- arch/arm64/include/asm/cpucaps.h | 3 +- arch/arm64/include/asm/cpufeature.h | 8 +- arch/arm64/include/asm/mmu_context.h | 13 ++ arch/arm64/kernel/cpufeature.c | 219 ++++++++++++++---- arch/arm64/kernel/cpuinfo.c | 53 +++-- arch/arm64/kernel/process.c | 19 +- arch/arm64/kvm/arm.c | 11 +- include/linux/cpuset.h | 3 +- include/linux/mmu_context.h | 8 + include/linux/sched.h | 1 + kernel/cgroup/cpuset.c | 39 ++-- kernel/sched/core.c | 112 +++++++-- 15 files changed, 426 insertions(+), 124 deletions(-) -- 2.29.2.576.ga3fc446d84-goog