From patchwork Sun May 1 13:21:11 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 1263 Return-Path: Delivered-To: unknown Received: from imap.gmail.com (74.125.159.109) by localhost6.localdomain6 with IMAP4-SSL; 08 Jun 2011 14:50:37 -0000 Delivered-To: patches@linaro.org Received: by 10.224.2.73 with SMTP id 9cs230867qai; Sun, 1 May 2011 06:22:24 -0700 (PDT) Received: by 10.100.56.29 with SMTP id e29mr2886697ana.129.1304256143929; Sun, 01 May 2011 06:22:23 -0700 (PDT) Received: from e4.ny.us.ibm.com (e4.ny.us.ibm.com [32.97.182.144]) by mx.google.com with ESMTPS id q6si7429210ani.33.2011.05.01.06.22.23 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 01 May 2011 06:22:23 -0700 (PDT) Received-SPF: pass (google.com: domain of paulmck@linux.vnet.ibm.com designates 32.97.182.144 as permitted sender) client-ip=32.97.182.144; Authentication-Results: mx.google.com; spf=pass (google.com: domain of paulmck@linux.vnet.ibm.com designates 32.97.182.144 as permitted sender) smtp.mail=paulmck@linux.vnet.ibm.com Received: from d01relay05.pok.ibm.com (d01relay05.pok.ibm.com [9.56.227.237]) by e4.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p41D1tAP007934; Sun, 1 May 2011 09:01:55 -0400 Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p41DMNPB059932; Sun, 1 May 2011 09:22:23 -0400 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p41DMHC8019629; Sun, 1 May 2011 09:22:22 -0400 Received: from paulmck-ThinkPad-W500 (sig-9-65-224-93.mts.ibm.com [9.65.224.93]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p41DMErx019302; Sun, 1 May 2011 09:22:15 -0400 Received: by paulmck-ThinkPad-W500 (Postfix, from userid 1000) id 8B71A13F80D; Sun, 1 May 2011 06:22:08 -0700 (PDT) From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, patches@linaro.org, "Paul E. McKenney" , "Paul E. McKenney" Subject: [PATCH tip/core/rcu 31/86] rcu: further lower priority in rcu_yield() Date: Sun, 1 May 2011 06:21:11 -0700 Message-Id: <1304256126-26015-31-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.3.2 In-Reply-To: <20110501132142.GA25494@linux.vnet.ibm.com> References: <20110501132142.GA25494@linux.vnet.ibm.com> From: Paul E. McKenney Although rcu_yield() dropped from real-time to normal priority, there is always the possibility that the competing tasks have been niced. So nice to 19 in rcu_yield() to help ensure that other tasks have a better chance of running. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney --- kernel/rcutree.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 3295c7b..963b4b1 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1561,6 +1561,7 @@ static void rcu_yield(void (*f)(unsigned long), unsigned long arg) mod_timer(&yield_timer, jiffies + 2); sp.sched_priority = 0; sched_setscheduler_nocheck(current, SCHED_NORMAL, &sp); + set_user_nice(current, 19); schedule(); sp.sched_priority = RCU_KTHREAD_PRIO; sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);