From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751518AbdAUUoF (ORCPT ); Sat, 21 Jan 2017 15:44:05 -0500 Received: from relay6-d.mail.gandi.net ([217.70.183.198]:50175 "EHLO relay6-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750894AbdAUUn5 (ORCPT ); Sat, 21 Jan 2017 15:43:57 -0500 X-Originating-IP: 50.39.169.170 Date: Sat, 21 Jan 2017 12:43:44 -0800 From: Josh Triplett To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, 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 Subject: Re: [PATCH v2 tip/core/rcu 08/18] rcu: Remove short-term CPU kicking Message-ID: <20170121204344.z2yjx6ouenurgduu@x> References: <20170118025316.GB2042@linux.vnet.ibm.com> <1484708037-2523-8-git-send-email-paulmck@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1484708037-2523-8-git-send-email-paulmck@linux.vnet.ibm.com> User-Agent: NeoMutt/20161126 (1.7.1) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 17, 2017 at 06:53:47PM -0800, Paul E. McKenney wrote: > Commit 4914950aaa12d ("rcu: Stop treating in-kernel CPU-bound workloads Does this commit ID still match what you have in your tree, post-rebase? > as errors") added a (relatively) short-timeout call to resched_cpu(). > This was inspired by as issue that was fixed by b7e7ade34e61 ("sched/core: > Fix remote wakeups"). But given that this issue was fixed, it is time > for the current commit to remove this call to resched_cpu(). > > Reported-by: Byungchul Park > Signed-off-by: Paul E. McKenney > Reviewed-by: Josh Triplett > --- > kernel/rcu/tree.c | 5 ----- > 1 file changed, 5 deletions(-) > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index 0e61b62e3f4a..5a4aaad75e76 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -1220,11 +1220,6 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp, > rdp->rsp->jiffies_resched += 5; /* Re-enable beating. */ > } > > - /* And if it has been a really long time, kick the CPU as well. */ > - if (ULONG_CMP_GE(jiffies, > - rdp->rsp->gp_start + 2 * jiffies_till_sched_qs) || > - ULONG_CMP_GE(jiffies, rdp->rsp->gp_start + jiffies_till_sched_qs)) > - resched_cpu(rdp->cpu); /* Force CPU into scheduler. */ > /* > * If more than halfway to RCU CPU stall-warning time, do > * a resched_cpu() to try to loosen things up a bit. > -- > 2.5.2 >