From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Subject: [PATCH 0/4 RFC] preemptible RCU Date: Tue, 7 Aug 2007 11:39:46 -0700 Message-ID: <20070807183946.GA32110@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-rt-users@vger.kernel.org, mingo@elte.hu, akpm@linux-foundation.org, dipankar@in.ibm.com, josht@linux.vnet.ibm.com, tytso@us.ibm.com, dvhltc@us.ibm.com, tglx@linutronix.de To: linux-kernel@vger.kernel.org Return-path: Received: from e3.ny.us.ibm.com ([32.97.182.143]:47705 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750813AbXHGSjs (ORCPT ); Tue, 7 Aug 2007 14:39:48 -0400 Content-Disposition: inline Sender: linux-rt-users-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org Hello! This patchset is an update of that posted by Dipankar last January (http://lkml.org/lkml/2007/1/15/133). This is work in progress, not yet ready for inclusion. It passes rcutorture on i386, x86_64, and ppc64 boxes as well as kernbench, so should be safe for experimentation. As with Dipankar's previous post, this variant of preemptible rcu_read_lock() and rcu_read_unlock may be invoked from NMI/SMI handlers, and do not contain any heavyweight atomic operations or memory barriers (although they do still momentarily disable IRQs). This patchset features a fully parallel grace-period computation, which will become increasingly important with upcoming multicore/multi-threaded CPUs. In addition, this patchset provides a preemptible-RCU variant of synchronize_sched() that avoids the previous deadlock with CPU hotplug -- this variant may eventually prove unnecessary, but is offered in the spirit of separating concerns. Next steps: (1) Integrate with CPU hotplug. (2) Re-merge RCU priority boosting. (3) Fix some naming issues. Longer term work includes optimized dyntick operation and eliminating the interrupt disabling in rcu_read_lock() and rcu_read_unlock(). Thanx, Paul