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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, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 11/12] rcu: Inline _synchronize_rcu_expedited() into synchronize_rcu_expedited() Date: Wed, 9 Jan 2019 13:18:49 -0800 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190109211830.GA30595@linux.ibm.com> References: <20190109211830.GA30595@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19010921-0068-0000-0000-000003800515 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010374; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000274; SDB=6.01144142; UDB=6.00595706; IPR=6.00924404; MB=3.00025056; MTD=3.00000008; XFM=3.00000015; UTC=2019-01-09 21:18:58 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19010921-0069-0000-0000-000047121E1B Message-Id: <20190109211850.31599-11-paulmck@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=999 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 Now that _synchronize_rcu_expedited() has only one caller, and given that this is a tail call, this commit inlines _synchronize_rcu_expedited() into synchronize_rcu_expedited(). Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_exp.h | 81 +++++++++++++++++++------------------------ 1 file changed, 36 insertions(+), 45 deletions(-) diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 353d113c0cd4..d882ca0cd01b 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -599,50 +599,6 @@ static void wait_rcu_exp_gp(struct work_struct *wp) rcu_exp_sel_wait_wake(rewp->rew_s); } -/* - * Given a smp_call_function() handler, kick off the specified - * implementation of expedited grace period. - */ -static void _synchronize_rcu_expedited(void) -{ - struct rcu_data *rdp; - struct rcu_exp_work rew; - struct rcu_node *rnp; - unsigned long s; - - /* If expedited grace periods are prohibited, fall back to normal. */ - if (rcu_gp_is_normal()) { - wait_rcu_gp(call_rcu); - return; - } - - /* Take a snapshot of the sequence number. */ - s = rcu_exp_gp_seq_snap(); - if (exp_funnel_lock(s)) - return; /* Someone else did our work for us. */ - - /* Ensure that load happens before action based on it. */ - if (unlikely(rcu_scheduler_active == RCU_SCHEDULER_INIT)) { - /* Direct call during scheduler init and early_initcalls(). */ - rcu_exp_sel_wait_wake(s); - } else { - /* Marshall arguments & schedule the expedited grace period. */ - rew.rew_s = s; - INIT_WORK_ONSTACK(&rew.rew_work, wait_rcu_exp_gp); - queue_work(rcu_gp_wq, &rew.rew_work); - } - - /* Wait for expedited grace period to complete. */ - rdp = per_cpu_ptr(&rcu_data, raw_smp_processor_id()); - rnp = rcu_get_root(); - wait_event(rnp->exp_wq[rcu_seq_ctr(s) & 0x3], - sync_exp_work_done(s)); - smp_mb(); /* Workqueue actions happen before return. */ - - /* Let the next expedited grace period start. */ - mutex_unlock(&rcu_state.exp_mutex); -} - #ifdef CONFIG_PREEMPT_RCU /* @@ -792,6 +748,11 @@ static void sync_sched_exp_online_cleanup(int cpu) */ void synchronize_rcu_expedited(void) { + struct rcu_data *rdp; + struct rcu_exp_work rew; + struct rcu_node *rnp; + unsigned long s; + RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map) || lock_is_held(&rcu_lock_map) || lock_is_held(&rcu_sched_lock_map), @@ -801,6 +762,36 @@ void synchronize_rcu_expedited(void) if (rcu_blocking_is_gp()) return; - _synchronize_rcu_expedited(); + /* If expedited grace periods are prohibited, fall back to normal. */ + if (rcu_gp_is_normal()) { + wait_rcu_gp(call_rcu); + return; + } + + /* Take a snapshot of the sequence number. */ + s = rcu_exp_gp_seq_snap(); + if (exp_funnel_lock(s)) + return; /* Someone else did our work for us. */ + + /* Ensure that load happens before action based on it. */ + if (unlikely(rcu_scheduler_active == RCU_SCHEDULER_INIT)) { + /* Direct call during scheduler init and early_initcalls(). */ + rcu_exp_sel_wait_wake(s); + } else { + /* Marshall arguments & schedule the expedited grace period. */ + rew.rew_s = s; + INIT_WORK_ONSTACK(&rew.rew_work, wait_rcu_exp_gp); + queue_work(rcu_gp_wq, &rew.rew_work); + } + + /* Wait for expedited grace period to complete. */ + rdp = per_cpu_ptr(&rcu_data, raw_smp_processor_id()); + rnp = rcu_get_root(); + wait_event(rnp->exp_wq[rcu_seq_ctr(s) & 0x3], + sync_exp_work_done(s)); + smp_mb(); /* Workqueue actions happen before return. */ + + /* Let the next expedited grace period start. */ + mutex_unlock(&rcu_state.exp_mutex); } EXPORT_SYMBOL_GPL(synchronize_rcu_expedited); -- 2.17.1