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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 6C5D0C4360C for ; Thu, 3 Oct 2019 01:38:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3201C222C2 for ; Thu, 3 Oct 2019 01:38:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570066717; bh=DWFzTLVMJ2lb38P7yieK3u1L5vc+qIiH05ds6lWnZzw=; h=Date:From:To:Cc:Subject:Reply-To:List-ID:From; b=tniN8WBjW3be9lzLAx1mVomxtbARbTiHN3iHkn17kg2ebxo+LvBilK6IGw1sPosgI M59ZexdtDlE4y/XVlVWy0NyVGk+u797rUYxtirIuM39DgVmmYRWlZeNpRRNAvsfMHE IUBNZcf6hfVR/jNF8N4Bql30J/wncwPZnfaGm0Ns= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725799AbfJCBih (ORCPT ); Wed, 2 Oct 2019 21:38:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:44526 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726376AbfJCBig (ORCPT ); Wed, 2 Oct 2019 21:38:36 -0400 Received: from paulmck-ThinkPad-P72 (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 09D2B222BE; Thu, 3 Oct 2019 01:38:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570066716; bh=DWFzTLVMJ2lb38P7yieK3u1L5vc+qIiH05ds6lWnZzw=; h=Date:From:To:Cc:Subject:Reply-To:From; b=RgAdjpzCpZRxcbGDm7spmnQjPhCIxojSHwBTS/Mgs2wRxmqYMF22xm8gUZFZvAjG8 3PSxnG1UTQ8BCzO8aSSMPN0NG6EtXkOxl/d5k1cDPtEt1eijmhWJj3cqVYwF0cvr+W E1qdwEU7o/z4xLN06YUPI1XTQzPKg61Idnibocrw= Date: Wed, 2 Oct 2019 18:38:34 -0700 From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org Subject: [PATCH tip/core/rcu 0/12] NO_HZ fixes for v5.5 Message-ID: <20191003013834.GA12927@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) Sender: rcu-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org Hello! This series contains various fixes for NO_HZ and NO_HZ_FULL problems, including re-enabling the tick during long-term kernel-mode execution. 1. Add TICK_DEP_BIT_RCU (which allows RCU-specific tick re-enabling), courtesy of Frederic Weisbecker. 2. Export tick start/stop functions for rcutorture. 3. Force on tick when invoking lots of callbacks. 4. Force on tick for rcutorture readers and callback flooders. 5. Provide RCU quiescent state in multi_cpu_stop(). 6. Make CPU-hotplug removal operations enable tick. 7. Use {READ,WRITE)_ONCE() for multi_cpu_stop() ->state. 8. Force tick on for nohz_full CPUs not reaching quiescent states. 9. Force nohz_full tick on upon irq enter instead of exit. 10. Reset CPU hints when reporting a quiescent state, courtesy of Joel Fernandes. 11. Confine ->core_needs_qs accesses to the corresponding CPU. 12. Make kernel-mode nohz_full CPUs invoke the RCU core processing. Thanx, Paul ------------------------------------------------------------------------ include/linux/rcutree.h | 1 include/linux/tick.h | 7 ++ include/trace/events/timer.h | 3 - kernel/rcu/rcutorture.c | 20 +++++--- kernel/rcu/tree.c | 105 ++++++++++++++++++++++++++++++------------- kernel/rcu/tree.h | 1 kernel/stop_machine.c | 7 +- kernel/time/tick-sched.c | 11 ++++ 8 files changed, 114 insertions(+), 41 deletions(-)