From 0beefa208bb3a9e581a60125703409ebe6f7fa53 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 17 Jun 2008 09:12:03 +0200 Subject: [PATCH] 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 Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/kernel/process.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 68ad3539b1..4061d63aab 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -267,17 +267,29 @@ static void c1e_idle(void) 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(); } -- 2.39.5