From: Shaohua Li <shaohua.li@intel.com>
To: lkml <linux-kernel@vger.kernel.org>
Cc: "Raj, Ashok" <ashok.raj@intel.com>, akpm <akpm@osdl.org>, ak <ak@muc.de>
Subject: trival patch: disable interrupt in play_dead
Date: Mon, 28 Nov 2005 22:48:16 -0800 [thread overview]
Message-ID: <1133246896.8076.4.camel@linux.site> (raw)
It's physical CPU hotplug now, so disable interrupt in play_dead.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
---
linux-2.6.14-root/arch/x86_64/kernel/process.c | 5 +++--
linux-2.6.14-root/include/asm-x86_64/system.h | 2 ++
2 files changed, 5 insertions(+), 2 deletions(-)
diff -puN arch/x86_64/kernel/process.c~cpuhp-disable-interrupt arch/x86_64/kernel/process.c
--- linux-2.6.14/arch/x86_64/kernel/process.c~cpuhp-disable-interrupt 2005-11-28 22:20:28.000000000 -0800
+++ linux-2.6.14-root/arch/x86_64/kernel/process.c 2005-11-28 22:20:28.000000000 -0800
@@ -157,7 +157,7 @@ EXPORT_SYMBOL_GPL(cpu_idle_wait);
DECLARE_PER_CPU(int, cpu_state);
#include <asm/nmi.h>
-/* We don't actually take CPU down, just spin without interrupts. */
+/* We halt the CPU with physical CPU hotplug */
static inline void play_dead(void)
{
idle_task_exit();
@@ -166,8 +166,9 @@ static inline void play_dead(void)
/* Ack it */
__get_cpu_var(cpu_state) = CPU_DEAD;
+ local_irq_disable();
while (1)
- safe_halt();
+ halt();
}
#else
static inline void play_dead(void)
diff -puN include/asm-x86_64/system.h~cpuhp-disable-interrupt include/asm-x86_64/system.h
--- linux-2.6.14/include/asm-x86_64/system.h~cpuhp-disable-interrupt 2005-11-28 22:20:28.000000000 -0800
+++ linux-2.6.14-root/include/asm-x86_64/system.h 2005-11-28 22:20:28.000000000 -0800
@@ -315,6 +315,8 @@ static inline unsigned long __cmpxchg(vo
#define local_irq_enable() __asm__ __volatile__("sti": : :"memory")
/* used in the idle loop; sti takes one instruction cycle to complete */
#define safe_halt() __asm__ __volatile__("sti; hlt": : :"memory")
+/* used when interrupts are already enabled or to shutdown the processor */
+#define halt() __asm__ __volatile__("hlt": : :"memory")
#define irqs_disabled() \
({ \
_
reply other threads:[~2005-11-28 23:27 UTC|newest]
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