From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lihao Liang Subject: Re: linux-next: Signed-off-by missing for commit in the rcu tree Date: Wed, 29 Nov 2017 10:48:19 +0800 Message-ID: <0d3da4c4-1eb3-bcdc-690b-7f864ab35073@huawei.com> References: <20171129115151.40b72764@canb.auug.org.au> <20171129011429.GB3624@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from szxga06-in.huawei.com ([45.249.212.32]:39189 "EHLO huawei.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752682AbdK2CtV (ORCPT ); Tue, 28 Nov 2017 21:49:21 -0500 In-Reply-To: <20171129011429.GB3624@linux.vnet.ibm.com> Content-Language: en-US Sender: linux-next-owner@vger.kernel.org List-ID: To: paulmck@linux.vnet.ibm.com, Stephen Rothwell Cc: Linux-Next Mailing List , Linux Kernel Mailing List , Hanjun Guo Hi Paul, Signed-off-by: Lihao Liang Many thanks, Lihao. On 2017/11/29 9:14, Paul E. McKenney wrote: > On Wed, Nov 29, 2017 at 11:51:51AM +1100, Stephen Rothwell wrote: >> Hi Paul, >> >> Commit >> >> d7e182c9c324 ("rcu: Remove unnecessary spinlock in rcu_boot_init_percpu_data()") >> >> is missing a Signed-off-by from its author. > > Good catch, Stephen! > > Lihao, would you please get me you Signed-off-by? The patch is below. > > Thanx, Paul > > ------------------------------------------------------------------------ > > commit d7e182c9c32480c1f579dd888ac50e88bfb39596 > Author: Liang Lihao > Date: Wed Nov 22 19:00:55 2017 +0000 > > rcu: Remove unnecessary spinlock in rcu_boot_init_percpu_data() > > Since rcu_boot_init_percpu_data() is only called at boot time, > there is no data race and spinlock is not needed. > > Signed-off-by: Paul E. McKenney > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index 69722817d6d6..0abe1db53d70 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -3636,12 +3636,9 @@ static void rcu_init_new_rnp(struct rcu_node *rnp_leaf) > static void __init > rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp) > { > - unsigned long flags; > struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu); > - struct rcu_node *rnp = rcu_get_root(rsp); > > /* Set up local state, ensuring consistent view of global state. */ > - raw_spin_lock_irqsave_rcu_node(rnp, flags); > rdp->grpmask = leaf_node_cpu_bit(rdp->mynode, cpu); > rdp->dynticks = &per_cpu(rcu_dynticks, cpu); > WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != 1); > @@ -3649,7 +3646,6 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp) > rdp->cpu = cpu; > rdp->rsp = rsp; > rcu_boot_init_nocb_percpu_data(rdp); > - raw_spin_unlock_irqrestore_rcu_node(rnp, flags); > } > > /* > > >