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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5336CECAAD8 for ; Thu, 22 Sep 2022 18:02:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232290AbiIVSCF (ORCPT ); Thu, 22 Sep 2022 14:02:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232342AbiIVSBT (ORCPT ); Thu, 22 Sep 2022 14:01:19 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B274852466 for ; Thu, 22 Sep 2022 11:01:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1663869671; 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; bh=QKj0XDJiFycujGKDCoaD+l0V6a5h4eQ/770vvHNlNfI=; b=RNIQDYL5ICACMvicIMnlZ5G11rcbQHE1YBAyx7j3tb8eIHH3+DSTaKRiaWqXfWhIt7tjT3 2kkOWwHG98D8RU4XB/5y2obgBAajiV/rjARqBjN3cTUB1ij9WJ3XCU1DxYHccd3s5bwW9O RkWm4OAzYCsl4/GIHZXrpYHE+zUMEDI= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-614-rsOsESkYNOWYBfJreKfKvg-1; Thu, 22 Sep 2022 14:01:09 -0400 X-MC-Unique: rsOsESkYNOWYBfJreKfKvg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 9D3BF3C30508; Thu, 22 Sep 2022 18:01:08 +0000 (UTC) Received: from llong.com (unknown [10.22.33.6]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3482414152E8; Thu, 22 Sep 2022 18:01:05 +0000 (UTC) From: Waiman Long To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , Tejun Heo , Zefan Li , Johannes Weiner , Will Deacon Cc: linux-kernel@vger.kernel.org, Linus Torvalds , Lai Jiangshan , Waiman Long Subject: [PATCH v10 0/5] sched: Persistent user requested affinity Date: Thu, 22 Sep 2022 14:00:36 -0400 Message-Id: <20220922180041.1768141-1-longman@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org v10: - Squash patches 4, 5 & 6 together into a single patch as suggested by PeterZ. v9: - Fix non-SMP config build errors in patch 4 reported by kernel test robot. - Disable user_cpus_ptr masking also when any of the SCA_MIGRATE_* flags are set. v8: - Add patches "sched: Introduce affinity_context structure" and "sched: Always clear user_cpus_ptr in do_set_cpus_allowed()" as suggested by PeterZ. - Better handle cpuset and sched_setaffinity() race in patch 5. v7: - Make changes recommended by Peter such as making scratch_mask allocation earlier and using percpu variable to pass information. The user_cpus_ptr field is added by commit b90ca8badbd1 ("sched: Introduce task_struct::user_cpus_ptr to track requested affinity") which uses it narrowly to allow keeping cpus affinity intact with asymmetric cpu setup. This patchset extends user_cpus_ptr to store user requested cpus affinity via the sched_setaffinity() API. With that information available, it will enable cpuset and other callers of set_cpus_allowed_ptr() like hotplug to keep cpus afinity as close to what the user wants as possible within the cpu list constraint of the current cpuset. Otherwise some change to the cpuset hierarchy or a hotplug event may reset the cpumask of the tasks in the affected cpusets to the default cpuset value even if those tasks have cpus affinity explicitly set by the users before. It also means that once sched_setaffinity() is called successfully, user_cpus_ptr will remain allocated until the task exits except in some rare circumstances. Waiman Long (5): sched: Add __releases annotations to affine_move_task() sched: Use user_cpus_ptr for saving user provided cpumask in sched_setaffinity() sched: Enforce user requested affinity sched: Handle set_cpus_allowed_ptr(), sched_setaffinity() & other races sched: Always clear user_cpus_ptr in do_set_cpus_allowed() kernel/sched/core.c | 231 +++++++++++++++++++++++++--------------- kernel/sched/deadline.c | 7 +- kernel/sched/sched.h | 22 +++- 3 files changed, 169 insertions(+), 91 deletions(-) -- 2.31.1