From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757537Ab0FUI5x (ORCPT ); Mon, 21 Jun 2010 04:57:53 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:64523 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753660Ab0FUI5w (ORCPT ); Mon, 21 Jun 2010 04:57:52 -0400 Message-ID: <4C1F2986.7080006@cn.fujitsu.com> Date: Mon, 21 Jun 2010 16:57:42 +0800 From: Lai Jiangshan User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) MIME-Version: 1.0 To: "Paul E. McKenney" , Ingo Molnar , Peter Zijlstra , LKML Subject: [PATCH] rcutorture: add random preemption Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add random preemption to help we to torture the preemptable rcu. srcu_read_delay() also calls rcu_read_delay() for shorter delays. Signed-off-by: Lai Jiangshan --- diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 2e2726d..7c81d07 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -303,6 +303,10 @@ static void rcu_read_delay(struct rcu_random_state *rrsp) mdelay(longdelay_ms); if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) udelay(shortdelay_us); +#ifdef CONFIG_PREEMPT + if (!preempt_count() && !(rcu_random(rrsp) % (nrealreaders * 20000))) + preempt_schedule(); +#endif } static void rcu_torture_read_unlock(int idx) __releases(RCU) @@ -536,6 +540,8 @@ static void srcu_read_delay(struct rcu_random_state *rrsp) delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick); if (!delay) schedule_timeout_interruptible(longdelay); + else + rcu_read_delay(rrsp); } static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl)