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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 0/12] Forward-progress changes for v5.1 Reply-To: paulmck@linux.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: 19010921-0060-0000-0000-000002F64003 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010375; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000274; SDB=6.01144145; UDB=6.00595709; IPR=6.00924407; MB=3.00025056; MTD=3.00000008; XFM=3.00000015; UTC=2019-01-09 21:28:21 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19010921-0061-0000-0000-000047DC70F5 Message-Id: <20190109212816.GA32282@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-01-09_10:,, 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=963 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1901090170 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! This series contains commits that improve RCU's ability to make forward progress on grace periods: 1. Accommodate zero jiffies_till_first_fqs and kthread kicking. 2-6. Move per-CPU variables to rcu_data structure, now that rcu_data is strictly per-CPU itself due to there only being one flavor. Also remove rcu_cpu_kthread_loops and rcu_cpu_kthread_cpu, which are unused. 7. Update outdated NOCB comments. 8. Improve diagnostics for failed RCU grace-period start. 9. Protect rcu_check_gp_kthread_starvation() access to ->gp_flags. 10. Add sysrq rcu_node-dump capability to assist with debugging of forward-progress issues. 11. Do RCU GP kthread self-wakeup from softirq and interrupt, thus fixing a grace-period hang, courtesy of Jun Zhang. 12. Prevent needless ->gp_seq_needed update in __note_gp_changes(), courtesy of Jun Zhang. Thanx, Paul ------------------------------------------------------------------------ Documentation/admin-guide/kernel-parameters.txt | 5 + kernel/rcu/tree.c | 106 ++++++++++++++++-------- kernel/rcu/tree.h | 19 ++-- kernel/rcu/tree_plugin.h | 68 ++++++--------- 4 files changed, 117 insertions(+), 81 deletions(-)