From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755712Ab2HWPCr (ORCPT ); Thu, 23 Aug 2012 11:02:47 -0400 Received: from mail-qa0-f46.google.com ([209.85.216.46]:64622 "EHLO mail-qa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752117Ab2HWO6r (ORCPT ); Thu, 23 Aug 2012 10:58:47 -0400 From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Richard Henderson , Ivan Kokshaysky , Matt Turner , alpha , "Paul E. McKenney" , Michael Cree Subject: [PATCH 01/11] alpha: Fix preemption handling in idle loop Date: Thu, 23 Aug 2012 16:58:25 +0200 Message-Id: <1345733915-20040-2-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1345733915-20040-1-git-send-email-fweisbec@gmail.com> References: <1345733915-20040-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org cpu_idle() is called on the boot CPU by the init code with preemption disabled. But the cpu_idle() function in alpha doesn't handle this when it calls schedule() directly. Fix it by converting it into schedule_preempt_disabled(). Also disable preemption before calling cpu_idle() from secondary CPU entry code to stay consistent with this state. Signed-off-by: Frederic Weisbecker Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: alpha Cc: Paul E. McKenney Cc: Michael Cree --- arch/alpha/kernel/process.c | 3 ++- arch/alpha/kernel/smp.c | 1 + 2 files changed, 3 insertions(+), 1 deletions(-) diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c index 153d3fc..eac5e01 100644 --- a/arch/alpha/kernel/process.c +++ b/arch/alpha/kernel/process.c @@ -56,7 +56,8 @@ cpu_idle(void) while (!need_resched()) cpu_relax(); - schedule(); + + schedule_preempt_disabled(); } } diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c index 35ddc02..a41ad90 100644 --- a/arch/alpha/kernel/smp.c +++ b/arch/alpha/kernel/smp.c @@ -166,6 +166,7 @@ smp_callin(void) DBGS(("smp_callin: commencing CPU %d current %p active_mm %p\n", cpuid, current, current->active_mm)); + preempt_disable(); /* Do nothing. */ cpu_idle(); } -- 1.7.5.4