From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753334AbaGaVI3 (ORCPT ); Thu, 31 Jul 2014 17:08:29 -0400 Received: from e35.co.us.ibm.com ([32.97.110.153]:60816 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752779AbaGaVI1 (ORCPT ); Thu, 31 Jul 2014 17:08:27 -0400 Date: Thu, 31 Jul 2014 14:08:22 -0700 From: "Paul E. McKenney" To: Andi Kleen Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, laijs@cn.fujitsu.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, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com Subject: Re: [PATCH v2 tip/core/rcu 0/10] RCU-tasks implementation Message-ID: <20140731210821.GD11241@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20140731003914.GA3872@linux.vnet.ibm.com> <871tt1qqcf.fsf@tassilo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871tt1qqcf.fsf@tassilo.jf.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14073121-6688-0000-0000-000003AFFDC1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 31, 2014 at 12:29:36PM -0700, Andi Kleen wrote: > "Paul E. McKenney" writes: > > > Hello! > > > > This series provides a prototype of an RCU-tasks implementation, which has > > been requested to assist with tramopoline removal. > > Is that trampoline removal (whatever it is) important enough to justify > adding that much new (and complicated) code? Are there other potential > users of this? Is the long term maintenance cost justified? > Will RCU keep growing forever? My answers to all of these questions is "I don't know." That said, I cannot resist pointing out that similar questions could be asked of a great many other subsystems of the Linux kernel, or indeed of the Linux kernel as a whole. ;-) And things do appear to be moving in a good direction for RCU-tasks: v1: 18 files changed, 749 insertions(+), 55 deletions(-) v2: 18 files changed, 590 insertions(+), 83 deletions(-) v3: 17 files changed, 447 insertions(+), 32 deletions(-) The numbers for v3 are tentative, and might change based on test results. Thanx, Paul