From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40892C433F4 for ; Wed, 29 Aug 2018 22:21:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D74292064E for ; Wed, 29 Aug 2018 22:21:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D74292064E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.vnet.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727632AbeH3CUm (ORCPT ); Wed, 29 Aug 2018 22:20:42 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:42260 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727378AbeH3CTz (ORCPT ); Wed, 29 Aug 2018 22:19:55 -0400 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w7TMJBa9117160 for ; Wed, 29 Aug 2018 18:20:56 -0400 Received: from e15.ny.us.ibm.com (e15.ny.us.ibm.com [129.33.205.205]) by mx0a-001b2d01.pphosted.com with ESMTP id 2m637yhts1-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 29 Aug 2018 18:20:56 -0400 Received: from localhost by e15.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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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 18/19] rcu: Remove rcu_state_p pointer to default rcu_state structure Date: Wed, 29 Aug 2018 15:20:46 -0700 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180829222021.GA29944@linux.vnet.ibm.com> References: <20180829222021.GA29944@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18082922-0068-0000-0000-00000331B7B7 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009636; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01080738; UDB=6.00557494; IPR=6.00860723; MB=3.00023001; MTD=3.00000008; XFM=3.00000015; UTC=2018-08-29 22:20:55 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18082922-0069-0000-0000-0000458F0E12 Message-Id: <20180829222047.319-18-paulmck@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=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1808290217 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The rcu_state_p pointer references the default rcu_state structure, that is, the one that call_rcu() uses, as opposed to call_rcu_bh() and sometimes call_rcu_sched(). But there is now only one rcu_state structure, so that one structure is by definition the default, which means that the rcu_state_p pointer no longer serves any useful purpose. This commit therefore removes it. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 27 ++++++++++++--------------- kernel/rcu/tree_exp.h | 2 +- kernel/rcu/tree_plugin.h | 16 ++++++++-------- 3 files changed, 21 insertions(+), 24 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 1dd8086ee90d..a3bcf08ad596 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -85,7 +85,6 @@ struct rcu_state rcu_state = { .ofl_lock = __SPIN_LOCK_UNLOCKED(rcu_state.ofl_lock), }; -static struct rcu_state *const rcu_state_p = &rcu_state; static struct rcu_data __percpu *const rcu_data_p = &rcu_data; LIST_HEAD(rcu_struct_flavors); @@ -491,7 +490,7 @@ static int rcu_pending(void); */ unsigned long rcu_get_gp_seq(void) { - return READ_ONCE(rcu_state_p->gp_seq); + return READ_ONCE(rcu_state.gp_seq); } EXPORT_SYMBOL_GPL(rcu_get_gp_seq); @@ -510,7 +509,7 @@ EXPORT_SYMBOL_GPL(rcu_sched_get_gp_seq); */ unsigned long rcu_bh_get_gp_seq(void) { - return READ_ONCE(rcu_state_p->gp_seq); + return READ_ONCE(rcu_state.gp_seq); } EXPORT_SYMBOL_GPL(rcu_bh_get_gp_seq); @@ -522,7 +521,7 @@ EXPORT_SYMBOL_GPL(rcu_bh_get_gp_seq); */ unsigned long rcu_exp_batches_completed(void) { - return rcu_state_p->expedited_sequence; + return rcu_state.expedited_sequence; } EXPORT_SYMBOL_GPL(rcu_exp_batches_completed); @@ -541,7 +540,7 @@ EXPORT_SYMBOL_GPL(rcu_exp_batches_completed_sched); */ void rcu_force_quiescent_state(void) { - force_quiescent_state(rcu_state_p); + force_quiescent_state(&rcu_state); } EXPORT_SYMBOL_GPL(rcu_force_quiescent_state); @@ -550,7 +549,7 @@ EXPORT_SYMBOL_GPL(rcu_force_quiescent_state); */ void rcu_bh_force_quiescent_state(void) { - force_quiescent_state(rcu_state_p); + force_quiescent_state(&rcu_state); } EXPORT_SYMBOL_GPL(rcu_bh_force_quiescent_state); @@ -611,7 +610,7 @@ void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags, case RCU_FLAVOR: case RCU_BH_FLAVOR: case RCU_SCHED_FLAVOR: - rsp = rcu_state_p; + rsp = &rcu_state; break; default: break; @@ -2291,7 +2290,6 @@ rcu_report_unblock_qs_rnp(struct rcu_state *rsp, raw_lockdep_assert_held_rcu_node(rnp); if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_PREEMPT)) || - WARN_ON_ONCE(rsp != rcu_state_p) || WARN_ON_ONCE(rcu_preempt_blocked_readers_cgp(rnp)) || rnp->qsmask != 0) { raw_spin_unlock_irqrestore_rcu_node(rnp, flags); @@ -2603,7 +2601,6 @@ static void force_qs_rnp(struct rcu_state *rsp, int (*f)(struct rcu_data *rsp)) raw_spin_lock_irqsave_rcu_node(rnp, flags); if (rnp->qsmask == 0) { if (!IS_ENABLED(CONFIG_PREEMPT) || - rsp != rcu_state_p || rcu_preempt_blocked_readers_cgp(rnp)) { /* * No point in scanning bits because they @@ -2972,7 +2969,7 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func, */ void call_rcu(struct rcu_head *head, rcu_callback_t func) { - __call_rcu(head, func, rcu_state_p, -1, 0); + __call_rcu(head, func, &rcu_state, -1, 0); } EXPORT_SYMBOL_GPL(call_rcu); @@ -2999,7 +2996,7 @@ EXPORT_SYMBOL_GPL(call_rcu_sched); void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) { - __call_rcu(head, func, rcu_state_p, -1, 1); + __call_rcu(head, func, &rcu_state, -1, 1); } EXPORT_SYMBOL_GPL(kfree_call_rcu); @@ -3028,7 +3025,7 @@ unsigned long get_state_synchronize_rcu(void) * before the load from ->gp_seq. */ smp_mb(); /* ^^^ */ - return rcu_seq_snap(&rcu_state_p->gp_seq); + return rcu_seq_snap(&rcu_state.gp_seq); } EXPORT_SYMBOL_GPL(get_state_synchronize_rcu); @@ -3048,7 +3045,7 @@ EXPORT_SYMBOL_GPL(get_state_synchronize_rcu); */ void cond_synchronize_rcu(unsigned long oldstate) { - if (!rcu_seq_done(&rcu_state_p->gp_seq, oldstate)) + if (!rcu_seq_done(&rcu_state.gp_seq, oldstate)) synchronize_rcu(); else smp_mb(); /* Ensure GP ends before subsequent accesses. */ @@ -3307,7 +3304,7 @@ static void _rcu_barrier(struct rcu_state *rsp) */ void rcu_barrier_bh(void) { - _rcu_barrier(rcu_state_p); + _rcu_barrier(&rcu_state); } EXPORT_SYMBOL_GPL(rcu_barrier_bh); @@ -3321,7 +3318,7 @@ EXPORT_SYMBOL_GPL(rcu_barrier_bh); */ void rcu_barrier(void) { - _rcu_barrier(rcu_state_p); + _rcu_barrier(&rcu_state); } EXPORT_SYMBOL_GPL(rcu_barrier); diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 3a8a582d9958..298a6904bbcd 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -756,7 +756,7 @@ static void sync_sched_exp_online_cleanup(int cpu) */ void synchronize_rcu_expedited(void) { - struct rcu_state *rsp = rcu_state_p; + struct rcu_state *rsp = &rcu_state; RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map) || lock_is_held(&rcu_lock_map) || diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index b7a99a6e64b6..329d5802d899 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -381,7 +381,7 @@ void rcu_note_context_switch(bool preempt) */ rcu_qs(); if (rdp->deferred_qs) - rcu_report_exp_rdp(rcu_state_p, rdp); + rcu_report_exp_rdp(&rcu_state, rdp); trace_rcu_utilization(TPS("End context switch")); barrier(); /* Avoid RCU read-side critical sections leaking up. */ } @@ -509,7 +509,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) * blocked-tasks list below. */ if (rdp->deferred_qs) { - rcu_report_exp_rdp(rcu_state_p, rdp); + rcu_report_exp_rdp(&rcu_state, rdp); if (!t->rcu_read_unlock_special.s) { local_irq_restore(flags); return; @@ -566,7 +566,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) rnp->grplo, rnp->grphi, !!rnp->gp_tasks); - rcu_report_unblock_qs_rnp(rcu_state_p, rnp, flags); + rcu_report_unblock_qs_rnp(&rcu_state, rnp, flags); } else { raw_spin_unlock_irqrestore_rcu_node(rnp, flags); } @@ -580,7 +580,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) * then we need to report up the rcu_node hierarchy. */ if (!empty_exp && empty_exp_now) - rcu_report_exp_rnp(rcu_state_p, rnp, true); + rcu_report_exp_rnp(&rcu_state, rnp, true); } else { local_irq_restore(flags); } @@ -1300,7 +1300,7 @@ static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp, struct sched_param sp; struct task_struct *t; - if (rcu_state_p != rsp) + if (&rcu_state != rsp) return 0; if (!rcu_scheduler_fully_active || rcu_rnp_online_cpus(rnp) == 0) @@ -1431,8 +1431,8 @@ static void __init rcu_spawn_boost_kthreads(void) for_each_possible_cpu(cpu) per_cpu(rcu_cpu_has_work, cpu) = 0; BUG_ON(smpboot_register_percpu_thread(&rcu_cpu_thread_spec)); - rcu_for_each_leaf_node(rcu_state_p, rnp) - (void)rcu_spawn_one_boost_kthread(rcu_state_p, rnp); + rcu_for_each_leaf_node(&rcu_state, rnp) + (void)rcu_spawn_one_boost_kthread(&rcu_state, rnp); } static void rcu_prepare_kthreads(int cpu) @@ -1442,7 +1442,7 @@ static void rcu_prepare_kthreads(int cpu) /* Fire up the incoming CPU's kthread and leaf rcu_node kthread. */ if (rcu_scheduler_fully_active) - (void)rcu_spawn_one_boost_kthread(rcu_state_p, rnp); + (void)rcu_spawn_one_boost_kthread(&rcu_state, rnp); } #else /* #ifdef CONFIG_RCU_BOOST */ -- 2.17.1