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From: Steven Rostedt <rostedt@goodmis.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
	linux-rt-users <linux-rt-users@vger.kernel.org>,
	Clark Williams <clark@redhat.com>,
	"Luis Claudio R. Goncalves" <lclaudio@uudg.org>,
	Fernando Lopez-Lezcano <nando@ccrma.Stanford.EDU>
Subject: Re: [ANNOUNCE] 3.2.9-rt15
Date: Mon, 05 Mar 2012 17:14:00 -0500	[thread overview]
Message-ID: <1330985640.25686.342.camel@gandalf.stny.rr.com> (raw)
In-Reply-To: <alpine.LFD.2.02.1203021743040.2742@ionos>

Thomas,

Please fold this change into

   cpu-rt-make-hotplug-lock-a-sleeping-spinlock-on-rt.patch


As the patch was never tested (nor even compiled) it introduced a nasty
bug into taking a CPU down instead of fixing one.

Thanks,

-- Steve

diff --git a/kernel/cpu.c b/kernel/cpu.c
index c25b5ff..66dfb74 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -59,16 +59,20 @@ static struct {
 	int refcount;
 } cpu_hotplug = {
 	.active_writer = NULL,
+#ifdef CONFIG_PREEMPT_RT_FULL
+	.lock = __SPIN_LOCK_UNLOCKED(cpu_hotplug.lock),
+#else
 	.lock = __MUTEX_INITIALIZER(cpu_hotplug.lock),
+#endif
 	.refcount = 0,
 };
 
 #ifdef CONFIG_PREEMPT_RT_FULL
-# define hotplug_lock() spin_lock(&cpu_hotplug.lock)
-# define hotplug_unlock() spin_unlock(&cpu_hotplug.lock)
+# define hotplug_lock() rt_spin_lock(&cpu_hotplug.lock)
+# define hotplug_unlock() rt_spin_unlock(&cpu_hotplug.lock)
 #else
 # define hotplug_lock() mutex_lock(&cpu_hotplug.lock)
-# define hotplug_lock() mutex_unlock(&cpu_hotplug.lock)
+# define hotplug_unlock() mutex_unlock(&cpu_hotplug.lock)
 #endif
 
 struct hotplug_pcp {



  reply	other threads:[~2012-03-05 22:14 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-02 17:01 [ANNOUNCE] 3.2.9-rt15 Thomas Gleixner
2012-03-05 22:14 ` Steven Rostedt [this message]
2012-03-06  4:15   ` Fernando Lopez-Lezcano
2012-03-06  8:20   ` Thomas Gleixner

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