From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 260403B7B71 for ; Fri, 26 Jun 2026 18:37:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782499058; cv=none; b=TWD7IpGSqYDzMible7l7KTrjdwaSlvNqkAJe11DVuqsmw6Gdk1aBr1keum/IcWHovr8hFcB/xh+C5YmGZ+zFHdy0tN74ip+rdjueIiAU5r+lcRYa2E356IQ40pWricPglYFrEJmB6yFmv4G8OIRg0WA1QNY04yunfV8CxXprDF0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782499058; c=relaxed/simple; bh=6dDnymeCyAIjxRoJW74PZ/gV2/Qm9iNCg2yVKleCGx0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=ecUQ/h+jTx/SDvpN1Xzj8/DO2DVc5dVDk+CV35W89QQ/l/5X3p0PtOyvCQVApN7eM31ff3cLw4b4vP6KFJ4J9cZ7/m/Kr2gAgP8ASrUHcnBd2J3wspb3pbiw+xhrY2PfYmVZkd3NZxPc6qPDXtVWPRMHTKKnONMhzMr1CKy9PfM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=PTLB0fEA; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="PTLB0fEA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1782499056; 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; bh=Xg+gfZZRw6uxD4/DdDYAkO88l6qr/2Ph391mNIOILd4=; b=PTLB0fEAKcHHjN2447tjck6d2IPK9JieLCnjxoEGZ3ILyxJL/U55y5jODUIrKEp/V3wsId wOY1UtP+vI4617sJBjp63qh0ZdwV3sn8/vJa18v9LMF9TKerFYlj4uMNyg6vZEFvOOyqhZ yj5oZL6D0qbxhE5KCelHAPrFX2aOUWU= 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-638-vKbXLotSONuCiEMUmwOrWQ-1; Fri, 26 Jun 2026 14:37:30 -0400 X-MC-Unique: vKbXLotSONuCiEMUmwOrWQ-1 X-Mimecast-MFC-AGG-ID: vKbXLotSONuCiEMUmwOrWQ_1782499048 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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 077271955DC9; Fri, 26 Jun 2026 18:37:28 +0000 (UTC) Received: from llong-thinkpadp16vgen1.westford.csb (unknown [10.2.16.156]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id E358619560A3; Fri, 26 Jun 2026 18:37:23 +0000 (UTC) From: Waiman Long To: Ridong Chen , Tejun Heo , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Farhad Alemi , Andrew Morton , Shuah Khan Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Aaron Tomlin , Guopeng Zhang , Gregory Price , David Hildenbrand , Waiman Long Subject: [PATCH v8 00/11] cgroup/cpuset: Support multiple source/destination cpusets for cpuset_*attach() Date: Fri, 26 Jun 2026 14:19:12 -0400 Message-ID: <20260626181923.133658-1-longman@redhat.com> Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 v8: - Update patch 3 to make attach_in_progress a global flag which block all cpuset write operations until the attach is done. - Add a new patch 4 to collect most of the attach related variables into a attach_ctx structure as suggested by Ridong. - Add a test_cpuset selftest patch contributed by Michal Koutný. - Keep the existing Reviewed-by tags as there is no functional change to the other patches other than rename of some variables. Also add some new tags. v7: https://lore.kernel.org/lkml/20260621032816.1806773-1-longman@redhat.com/ - Include the fix patch from Farhad Alemi to fix a div/0 crash that was part of the old patch 1. - Integrated v6 patch 7 into earlier patches. - Add a new "cgroup/cpuset: Prevent race between task attach and cpuset state change" patch to ensure that there will be no cpuset state change between cpuset_can_attach() and cpuset_attach() or cpuset_cancel_attach(). - Break v6 patch 6 into 2 separate patches for supporting multiple source cpusets and multiple destination cpusets respectively and further simplify and streamline the code. v6: - Make guarantee_online_mems() to only return cs->effective_mems with v2 in patch 1. - Remove obsolete commit description text from patch 3. - Add Reviewed-by tags. - In patch 6, add WARN_ON_ONCE() test in cpuset_can_attach() to confirm that cs != oldcs. Sashiko AI review of another cpuset patch had found that cpuset_attach() and cpuset_can_attach() can be passed a cgroup_taskset with tasks migrating from one source cpuset to multiple destination cpusets and vice versa. Further testing of the cpuset code indicates that this is indeed the case when the v2 cpuset controller is enabled or disabled. Unfortunately, cpuset_attach() and cpuset_can_attach() still assume that there will be one source and one destinaton cpuset which may result in inocrrect behavior. This patch series is created to fix this issue. Patch 1 is a fix that fix a cgroup v2 div/0 crash due to bug in cpuset_update_tasks_nodemask(). Patch 2 is to fix an inconsistency in the way node mask update is being handled in cpuset_update_tasks_nodemask() and cpuset_attach() so that they match each other. Patch 3 makes any cpuset state change to wait for the completion of the pending cpuset attach operation, if any. Patch 4 collects task attach related data into a common attach_ctx structure. Patches 5 and 6 are just preparatory patches to make the remaining patches easier to review. Patch 7 makes attach_ctx.old_cs track group leader for use by cpuset_migrate_mm(). Patch 8 moves mpol_rebind_mm() and cpuset_migrate_mm() inside cpuset_attach_task() to make CLONE_INTO_CGROUP flag of clone(2) works more like moving task from one cpuset to another one, while also make supporting multiple source and destination cpusets easier. Patch 9 makes the necessary changes to enable the support of multiple source cpusets by keeping all the source cpusets found during task iterations in a singly linked lists. Patch 10 enables the support of multiple destination cpusets during the the enabling of cpuset v2 controller. Patch 11 adds new test case to test_cpuset to test disabling of cpuset controller. Farhad Alemi (1): cgroup/cpuset: rebind mm mempolicy to effective_mems, not mems_allowed Michal Koutný (1): selftests/cgroup: Add test for cpuset affinity on controller disable Waiman Long (9): cgroup/cpuset: Fix node inconsistencies between cpuset_update_tasks_nodemask() and cpuset_attach() cgroup/cpuset: Prevent race between task attach and cpuset state change cgroup/cpuset: Put all task attach related variables into attach_ctx cgroup/cpuset: Add a cpuset_reserve_dl_bw() helper cgroup/cpuset: Expand the scope of cpuset_can_attach_check() cgroup/cpuset: Make attach_ctx.old_cs track task group leader cgroup/cpuset: Move mpol_rebind_mm/cpuset_migrate_mm() calls inside cpuset_attach_task() cgroup/cpuset: Support multiple source cpusets for cpuset_*attach() cgroup/cpuset: Support multiple destination cpusets for cpuset_*attach() kernel/cgroup/cpuset-internal.h | 11 +- kernel/cgroup/cpuset.c | 442 ++++++++++++------- tools/testing/selftests/cgroup/test_cpuset.c | 243 ++++++++++ 3 files changed, 541 insertions(+), 155 deletions(-) -- 2.54.0