From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752544AbeEQOjR (ORCPT ); Thu, 17 May 2018 10:39:17 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:34144 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752505AbeEQOjP (ORCPT ); Thu, 17 May 2018 10:39:15 -0400 Date: Thu, 17 May 2018 07:40:44 -0700 From: "Paul E. McKenney" To: rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org Subject: RCU branching for the v4.19 merge window Reply-To: paulmck@linux.vnet.ibm.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 18051714-0040-0000-0000-0000042CE3D9 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009041; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000260; SDB=6.01033645; UDB=6.00528540; IPR=6.00812774; MB=3.00021162; MTD=3.00000008; XFM=3.00000015; UTC=2018-05-17 14:39:12 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18051714-0041-0000-0000-00000832FA15 Message-Id: <20180517144044.GA6089@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-05-17_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1805170134 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Steve! Another year, another difficult-to-branch set of RCU commits. In happy contrast to last year, I can make some branches (SRCU, some of the torture commits, and a few miscellaneous commits), but I will likely end up with several short branches and one huge one. My thought is to keep the long branch, but email the patches out in a few separate serieses, with each depending on its predecessor. For example, one series from the big branch would be folding the ->gpnum and ->completed fields into a single ->gp_seq, which helps the RCU-flavor consolidation task. Another series suppresses some rare false-positive splats that have been plaguing me for more than a year. Yet another series within this huge branch applies and optimizes funnel locking for grace-period startup. The problem is that the conversion to ->gp_seq has a very large footprint, which of course generates lots of conflicts. I could of course collapse these commits into a single commit, but if I did that I would also defer to the merge window following v4.19 due to the resulting loss of bisection within that change. Any advice? The commits are for-mingo..rcu/dev in my -rcu tree. Thanx, Paul