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McKenney" To: linux-kernel@vger.kernel.org Cc: 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 0/10] Forward-progress changes for v4.20/v5.0 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: 18082923-0060-0000-0000-000002A6658D X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009636; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01080751; UDB=6.00557502; IPR=6.00860737; MB=3.00023002; MTD=3.00000008; XFM=3.00000015; UTC=2018-08-29 23:00:39 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18082923-0061-0000-0000-00004655BF76 Message-Id: <20180829230035.GA7751@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-08-29_06:,, 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 mlxscore=0 impostorscore=0 mlxlogscore=685 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1808290224 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! This series includes changes that improve RCU's forward-progress guarantees for normal grace periods, with a few stray RCU-consolidation cleanups thrown in for good measure. 1. Make need_resched() respond to urgent RCU-QS needs. 2. Provide improved interrupt-from-idle check in rcu_check_callbacks(). 3. Make rcutorture dump out the reader protection sequence when an RCU failures or close calls occurs. 4. Motivate Tiny RCU forward progress. 5. Eliminate ->rcu_qs_ctr from the rcu_dynticks structure on account of its no longer being used. And let that be a lesson to the rest of that structure's fields!!! 6. Provide functions for determining if call_rcu() has been invoked for debugging purposes by the users of call_rcu(). 7. Compute jiffies_till_sched_qs from other kernel parameters, because one size simply does not fit all. 8. More aggressively enlist scheduler aid for nohz_full CPUs. After all, they might never see a scheduler-clock interrupt. 9. Avoid resched_cpu() when rescheduling the current CPU. 10. Convert "1UL << x" to "BIT(x)" to save a few characters. Thanx, Paul ------------------------------------------------------------------------ Documentation/admin-guide/kernel-parameters.txt | 9 + include/linux/rcupdate.h | 40 +++++ include/trace/events/rcu.h | 5 kernel/rcu/rcu.h | 5 kernel/rcu/rcutorture.c | 119 +++++++++++++--- kernel/rcu/tiny.c | 6 kernel/rcu/tree.c | 171 ++++++++++++++---------- kernel/rcu/tree.h | 6 kernel/rcu/tree_exp.h | 17 +- kernel/rcu/tree_plugin.h | 14 + 10 files changed, 280 insertions(+), 112 deletions(-)