From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755638AbcHVPXI (ORCPT ); Mon, 22 Aug 2016 11:23:08 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:40897 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755142AbcHVPXC (ORCPT ); Mon, 22 Aug 2016 11:23:02 -0400 X-IBM-Helo: d03dlp02.boulder.ibm.com X-IBM-MailFrom: paulmck@linux.vnet.ibm.com From: "Paul E. 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, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 1/6] rcu: Consolidate expedited grace period machinery Date: Mon, 22 Aug 2016 08:23:02 -0700 X-Mailer: git-send-email 2.5.2 In-Reply-To: <20160822152239.GA7153@linux.vnet.ibm.com> References: <20160822152239.GA7153@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16082215-0016-0000-0000-0000047A620B X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00005629; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000183; SDB=6.00748116; UDB=6.00353034; IPR=6.00520781; BA=6.00004672; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00012420; XFM=3.00000011; UTC=2016-08-22 15:23:00 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16082215-0017-0000-0000-0000323A88B0 Message-Id: <1471879387-7902-1-git-send-email-paulmck@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-08-22_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1608220159 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The functions synchronize_rcu_expedited() and synchronize_sched_expedite() have nearly identical code. This commit therefore consolidates this code into a new _synchronize_rcu_expedited() function. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_exp.h | 62 ++++++++++++++++++++++++--------------------------- 1 file changed, 29 insertions(+), 33 deletions(-) diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 6d86ab6ec2c9..1549f456fb7b 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -516,6 +516,33 @@ static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s) mutex_unlock(&rsp->exp_wake_mutex); } +/* + * Given an rcu_state pointer and a smp_call_function() handler, kick + * off the specified flavor of expedited grace period. + */ +static void _synchronize_rcu_expedited(struct rcu_state *rsp, + smp_call_func_t func) +{ + unsigned long s; + + /* If expedited grace periods are prohibited, fall back to normal. */ + if (rcu_gp_is_normal()) { + wait_rcu_gp(rsp->call); + return; + } + + /* Take a snapshot of the sequence number. */ + s = rcu_exp_gp_seq_snap(rsp); + if (exp_funnel_lock(rsp, s)) + return; /* Someone else did our work for us. */ + + /* Initialize the rcu_node tree in preparation for the wait. */ + sync_rcu_exp_select_cpus(rsp, func); + + /* Wait and clean up, including waking everyone. */ + rcu_exp_wait_wake(rsp, s); +} + /** * synchronize_sched_expedited - Brute-force RCU-sched grace period * @@ -534,29 +561,13 @@ static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s) */ void synchronize_sched_expedited(void) { - unsigned long s; struct rcu_state *rsp = &rcu_sched_state; /* If only one CPU, this is automatically a grace period. */ if (rcu_blocking_is_gp()) return; - /* If expedited grace periods are prohibited, fall back to normal. */ - if (rcu_gp_is_normal()) { - wait_rcu_gp(call_rcu_sched); - return; - } - - /* Take a snapshot of the sequence number. */ - s = rcu_exp_gp_seq_snap(rsp); - if (exp_funnel_lock(rsp, s)) - return; /* Someone else did our work for us. */ - - /* Initialize the rcu_node tree in preparation for the wait. */ - sync_rcu_exp_select_cpus(rsp, sync_sched_exp_handler); - - /* Wait and clean up, including waking everyone. */ - rcu_exp_wait_wake(rsp, s); + _synchronize_rcu_expedited(rsp, sync_sched_exp_handler); } EXPORT_SYMBOL_GPL(synchronize_sched_expedited); @@ -620,23 +631,8 @@ static void sync_rcu_exp_handler(void *info) void synchronize_rcu_expedited(void) { struct rcu_state *rsp = rcu_state_p; - unsigned long s; - /* If expedited grace periods are prohibited, fall back to normal. */ - if (rcu_gp_is_normal()) { - wait_rcu_gp(call_rcu); - return; - } - - s = rcu_exp_gp_seq_snap(rsp); - if (exp_funnel_lock(rsp, s)) - return; /* Someone else did our work for us. */ - - /* Initialize the rcu_node tree in preparation for the wait. */ - sync_rcu_exp_select_cpus(rsp, sync_rcu_exp_handler); - - /* Wait for ->blkd_tasks lists to drain, then wake everyone up. */ - rcu_exp_wait_wake(rsp, s); + _synchronize_rcu_expedited(rsp, sync_rcu_exp_handler); } EXPORT_SYMBOL_GPL(synchronize_rcu_expedited); -- 2.5.2