From patchwork Mon Apr 1 14:58:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Waiman Long X-Patchwork-Id: 13612810 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 7C66E28684 for ; Mon, 1 Apr 2024 14:59:24 +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=1711983566; cv=none; b=AEdtCnYqrngsOpc9iACcREOcXiT9wKhV2Kun/5N23YFIoU/h160+PSUXwFRnPNKfsC0i+/bMVTGYDdig3I7y+NawrkpWwkuUPEqz9A2asCYbxKJL4R6Ds7W4DHkPwmTYF+zSUEV2uGhPc1UmJxA4sWToBw7dfGQ+IvhPZLBRU0k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711983566; c=relaxed/simple; bh=+N7vB/l8eI+BsoWxlwCAb4p/o1JU7fDVp21tieM+N0U=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=S5Dcp7x9Ok/QLfVWYzyzKcvHJ7om7ysO0MWwkvueCgLgNM0xionQ4AzJt+r7cAjoHKm7suUeA+uh7mP4/46Ut9/dZDqTJ5z53gEURXskFqxOUQwBtBgEKiS/tzOhzrvzI8a/yqt6vcn8EFHFqWfI4bcqg7j64u1WQ57wiLFJEXc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=Pe9Yb4sL; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="Pe9Yb4sL" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1711983563; 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=tTOZ+xVZLIL276KYyTbnm56/gg9lamrdIo8smfPcjkg=; b=Pe9Yb4sLD3mtlm9gcOXiXwPU8QVlk8DV37IZHXuCwi6mu9Rp4rk09A9yTEB79JqA17bmRF IHlnU+C5Vm8FJhFox2oApsFjxF1L/jPTdoHrLAKZNs4IV6rfYoTxR3d3eE9KwfcHzrSYdM 9m4YMADUvX3srhuRb1kDzPrlpsQyIyY= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-664-Z94_VNTWNcOgc4Tmt2zvUw-1; Mon, 01 Apr 2024 10:59:18 -0400 X-MC-Unique: Z94_VNTWNcOgc4Tmt2zvUw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (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 mimecast-mx02.redhat.com (Postfix) with ESMTPS id 42ABC88F2EB; Mon, 1 Apr 2024 14:59:17 +0000 (UTC) Received: from llong.com (unknown [10.22.16.160]) by smtp.corp.redhat.com (Postfix) with ESMTP id 40C1511310; Mon, 1 Apr 2024 14:59:15 +0000 (UTC) From: Waiman Long To: Tejun Heo , Zefan Li , Johannes Weiner , Thomas Gleixner , Peter Zijlstra , "Rafael J. Wysocki" , Len Brown , Pavel Machek , Shuah Khan Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-pm@vger.kernel.org, linux-kselftest@vger.kernel.org, Frederic Weisbecker , "Paul E. McKenney" , Ingo Molnar , Valentin Schneider , Anna-Maria Behnsen , Alex Shi , Vincent Guittot , Barry Song , Waiman Long Subject: [PATCH 0/2] cgroup/cpuset: Make cpuset hotplug processing synchronous Date: Mon, 1 Apr 2024 10:58:56 -0400 Message-Id: <20240401145858.2656598-1-longman@redhat.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.5 As discussed in the LKML thread [1], the asynchronous nature of cpuset hotplug handling code is causing problem with RCU testing. With recent changes in the way locking is being handled in the cpuset code, it is now possible to make the cpuset hotplug code synchronous again without major changes. This series enables the hotplug code to call directly into cpuset hotplug core without indirection with the exception of the special case of v1 cpuset becoming empty still being handled indirectly with workqueue. A new simple test case was also written to test this special v1 cpuset case. The test_cpuset_prs.sh script was also run with LOCKDEP on to verify that there is no regression. [1] https://lore.kernel.org/lkml/ZgYikMb5kZ7rxPp6@slm.duckdns.org/ Waiman Long (2): cgroup/cpuset: Make cpuset hotplug processing synchronous cgroup/cpuset: Add test_cpuset_v1_hp.sh include/linux/cpuset.h | 3 - kernel/cgroup/cpuset.c | 131 +++++++----------- kernel/cpu.c | 48 ------- kernel/power/process.c | 2 - tools/testing/selftests/cgroup/Makefile | 2 +- .../selftests/cgroup/test_cpuset_v1_hp.sh | 40 ++++++ 6 files changed, 88 insertions(+), 138 deletions(-) create mode 100755 tools/testing/selftests/cgroup/test_cpuset_v1_hp.sh