x86: add C1E aware idle function, fix
On Tue, 17 Jun 2008, Rafael J. Wysocki wrote:
>
> BTW, with the C1E patches reverted I don't get the
> WARNING: at /home/rafael/src/linux-next/kernel/smp.c:215 smp_call_function_single+0x3d/0xa2
> in the log. Thomas?
The BROADCAST_FORCE notification uses smp_function_call and therefor
must be run with interrupts enabled.
While at it, add a comment for the BROADCAST_EXIT notifier as well.
Reported-and-bisected-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 68ad353..4061d63 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -267,17 +267,29 @@
if (!cpu_isset(cpu, c1e_mask)) {
cpu_set(cpu, c1e_mask);
- /* Force broadcast so ACPI can not interfere */
+ /*
+ * Force broadcast so ACPI can not interfere. Needs
+ * to run with interrupts enabled as it uses
+ * smp_function_call.
+ */
+ local_irq_enable();
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_FORCE,
&cpu);
printk(KERN_INFO "Switch to broadcast mode on CPU%d\n",
cpu);
+ local_irq_disable();
}
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
+
default_idle();
- local_irq_disable();
- clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
- local_irq_enable();
+
+ /*
+ * The switch back from broadcast mode needs to be
+ * called with interrupts disabled.
+ */
+ local_irq_disable();
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
+ local_irq_enable();
} else
default_idle();
}
