From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: [PATCH RT 19/25][RFC 3.0.23-rt39-rc1] timer: Fix hotplug for -rt Date: Tue, 06 Mar 2012 11:16:55 -0500 Message-ID: <20120306161950.996376388@goodmis.org> References: <20120306161636.491172179@goodmis.org> Cc: Thomas Gleixner , Carsten Emde , John Kacur , Peter Zijlstra , Clark Williams , stable-rt@vger.kernel.org To: linux-kernel@vger.kernel.org, linux-rt-users Return-path: Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:14866 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755745Ab2CFQTx (ORCPT ); Tue, 6 Mar 2012 11:19:53 -0500 Content-Disposition: inline; filename=0019-timer-Fix-hotplug-for-rt.patch Sender: linux-rt-users-owner@vger.kernel.org List-ID: From: Steven Rostedt Revert the RT patch: Author: Ingo Molnar Date: Fri Jul 3 08:30:32 2009 -0500 timers: fix timer hotplug on -rt Here we are in the CPU_DEAD notifier, and we must not sleep nor enable interrupts. There's no problem with sleeping in this notifier. But the get_cpu_var() had to be converted to a get_local_var(). Replace the previous fix with the get_local_var() convert. Signed-off-by: Steven Rostedt Cc: Carsten Emde Cc: John Kacur Cc: Peter Zijlstra Cc: Clark Williams Cc: stable-rt@vger.kernel.org Link: http://lkml.kernel.org/r/20120301190344.948157137@goodmis.org Signed-off-by: Thomas Gleixner --- kernel/timer.c | 16 +++++----------- 1 files changed, 5 insertions(+), 11 deletions(-) diff --git a/kernel/timer.c b/kernel/timer.c index 937799f..a319c6a 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1743,21 +1743,17 @@ static void __cpuinit migrate_timers(int cpu) { struct tvec_base *old_base; struct tvec_base *new_base; - unsigned long flags; int i; BUG_ON(cpu_online(cpu)); old_base = per_cpu(tvec_bases, cpu); - new_base = get_cpu_var(tvec_bases); + new_base = get_local_var(tvec_bases); /* * The caller is globally serialized and nobody else * takes two locks at once, deadlock is not possible. */ - local_irq_save(flags); - while (!spin_trylock(&new_base->lock)) - cpu_relax(); - while (!spin_trylock(&old_base->lock)) - cpu_relax(); + spin_lock_irq(&new_base->lock); + spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); BUG_ON(old_base->running_timer); @@ -1771,10 +1767,8 @@ static void __cpuinit migrate_timers(int cpu) } spin_unlock(&old_base->lock); - spin_unlock(&new_base->lock); - local_irq_restore(flags);