From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756181AbdGXVyW (ORCPT ); Mon, 24 Jul 2017 17:54:22 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:37884 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753568AbdGXVwC (ORCPT ); Mon, 24 Jul 2017 17:52:02 -0400 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, fweisbec@gmail.com, oleg@redhat.com, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 09/12] rcu: Advance callbacks after migration Date: Mon, 24 Jul 2017 14:51:53 -0700 X-Mailer: git-send-email 2.5.2 In-Reply-To: <20170724215139.GA10881@linux.vnet.ibm.com> References: <20170724215139.GA10881@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17072421-0056-0000-0000-000003AC099A X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007419; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000214; SDB=6.00892374; UDB=6.00446023; IPR=6.00672539; BA=6.00005489; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016356; XFM=3.00000015; UTC=2017-07-24 21:51:59 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17072421-0057-0000-0000-000007E226A2 Message-Id: <1500933116-11642-9-git-send-email-paulmck@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-07-24_13:,, 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=8.0.1-1706020000 definitions=main-1707240334 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When migrating callbacks from a newly offlined CPU, we are already holding the root rcu_node structure's lock, so it costs almost nothing to advance and accelerate the newly migrated callbacks. This patch therefore makes this advancing and acceleration happen. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 58ab489eca66..f9f01aeb5add 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3935,6 +3935,7 @@ static void rcu_migrate_callbacks(int cpu, struct rcu_state *rsp) rcu_advance_cbs(rsp, rnp_root, rdp); /* Leverage recent GPs. */ rcu_send_cbs_to_orphanage(cpu, rsp, rnp, rdp); rcu_adopt_orphan_cbs(rsp, flags); + rcu_advance_cbs(rsp, rnp_root, my_rdp); /* Assign GP to pending CBs. */ raw_spin_unlock_irqrestore_rcu_node(rnp_root, flags); WARN_ONCE(rcu_segcblist_n_cbs(&rdp->cblist) != 0 || !rcu_segcblist_empty(&rdp->cblist), -- 2.5.2