From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755898Ab1K1Xep (ORCPT ); Mon, 28 Nov 2011 18:34:45 -0500 Received: from e3.ny.us.ibm.com ([32.97.182.143]:37020 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755374Ab1K1Xd7 (ORCPT ); Mon, 28 Nov 2011 18:33:59 -0500 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 RFC tip/core/rcu 11/13] rcu: Identify dyntick-idle CPUs on first force_quiescent_state() pass Date: Mon, 28 Nov 2011 15:33:03 -0800 Message-Id: <1322523185-456-11-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.3.2 In-Reply-To: <20111128233212.GA32279@linux.vnet.ibm.com> References: <20111128233212.GA32279@linux.vnet.ibm.com> x-cbid: 11112823-8974-0000-0000-000003806470 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paul E. McKenney Fixes and workarounds for a number of issues (for example, that in df4012edc) make it safe to once again detect dyntick-idle CPUs on the first pass of force_quiescent_state(), so this commit makes that change. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney --- kernel/rcutree.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kernel/rcutree.c b/kernel/rcutree.c index aab9ed5..69bb372 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -607,7 +607,7 @@ int rcu_is_cpu_rrupt_from_idle(void) static int dyntick_save_progress_counter(struct rcu_data *rdp) { rdp->dynticks_snap = atomic_add_return(0, &rdp->dynticks->dynticks); - return 0; + return (rdp->dynticks_snap & 0x1) == 0; } /* -- 1.7.3.2