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Commit 98ad1cc1 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Paul E. McKenney
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x86: Call idle notifier after irq_enter() 



Interrupts notify the idle exit state before calling irq_enter().
But the notifier code calls rcu_read_lock() and this is not
allowed while rcu is in an extended quiescent state. We need
to wait for irq_enter() -> rcu_idle_exit() to be called before
doing so otherwise this results in a grumpy RCU:

[    0.099991] WARNING: at include/linux/rcupdate.h:194 __atomic_notifier_call_chain+0xd2/0x110()
[    0.099991] Hardware name: AMD690VM-FMH
[    0.099991] Modules linked in:
[    0.099991] Pid: 0, comm: swapper Not tainted 3.0.0-rc6+ #255
[    0.099991] Call Trace:
[    0.099991]  <IRQ>  [<ffffffff81051c8a>] warn_slowpath_common+0x7a/0xb0
[    0.099991]  [<ffffffff81051cd5>] warn_slowpath_null+0x15/0x20
[    0.099991]  [<ffffffff817d6fa2>] __atomic_notifier_call_chain+0xd2/0x110
[    0.099991]  [<ffffffff817d6ff1>] atomic_notifier_call_chain+0x11/0x20
[    0.099991]  [<ffffffff81001873>] exit_idle+0x43/0x50
[    0.099991]  [<ffffffff81020439>] smp_apic_timer_interrupt+0x39/0xa0
[    0.099991]  [<ffffffff817da253>] apic_timer_interrupt+0x13/0x20
[    0.099991]  <EOI>  [<ffffffff8100ae67>] ? default_idle+0xa7/0x350
[    0.099991]  [<ffffffff8100ae65>] ? default_idle+0xa5/0x350
[    0.099991]  [<ffffffff8100b19b>] amd_e400_idle+0x8b/0x110
[    0.099991]  [<ffffffff810cb01f>] ? rcu_enter_nohz+0x8f/0x160
[    0.099991]  [<ffffffff810019a0>] cpu_idle+0xb0/0x110
[    0.099991]  [<ffffffff817a7505>] rest_init+0xe5/0x140
[    0.099991]  [<ffffffff817a7468>] ? rest_init+0x48/0x140
[    0.099991]  [<ffffffff81cc5ca3>] start_kernel+0x3d1/0x3dc
[    0.099991]  [<ffffffff81cc5321>] x86_64_start_reservations+0x131/0x135
[    0.099991]  [<ffffffff81cc5412>] x86_64_start_kernel+0xed/0xf4

Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andy Henroid <andrew.d.henroid@intel.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: default avatarJosh Triplett <josh@joshtriplett.org>
parent e37e112d

arch/x86/kernel/apic/apic.c

+3 −3
Original line number Diff line number Diff line
@@ -876,8 +876,8 @@ void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs) 
	 * Besides, if we don't timer interrupts ignore the global

	 * interrupt lock, which is the WrongThing (tm) to do.

	 */

	exit_idle();

	irq_enter();

	exit_idle();

	local_apic_timer_interrupt();

	irq_exit();
@@ -1809,8 +1809,8 @@ void smp_spurious_interrupt(struct pt_regs *regs) 
{

	u32 v;



	exit_idle();

	irq_enter();

	exit_idle();

	/*

	 * Check if this really is a spurious interrupt and ACK it

	 * if it is a vectored one.  Just in case...
@@ -1846,8 +1846,8 @@ void smp_error_interrupt(struct pt_regs *regs) 
		"Illegal register address",	/* APIC Error Bit 7 */

	};



	exit_idle();

	irq_enter();

	exit_idle();

	/* First tickle the hardware, only then report what went on. -- REW */

	v0 = apic_read(APIC_ESR);

	apic_write(APIC_ESR, 0);

arch/x86/kernel/apic/io_apic.c

+1 −1
Original line number Diff line number Diff line
@@ -2421,8 +2421,8 @@ asmlinkage void smp_irq_move_cleanup_interrupt(void) 
	unsigned vector, me;



	ack_APIC_irq();

	exit_idle();

	irq_enter();

	exit_idle();



	me = smp_processor_id();

	for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {

arch/x86/kernel/cpu/mcheck/therm_throt.c

+1 −1
Original line number Diff line number Diff line
@@ -397,8 +397,8 @@ static void (*smp_thermal_vector)(void) = unexpected_thermal_interrupt; 


asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)

{

	exit_idle();

	irq_enter();

	exit_idle();

	inc_irq_stat(irq_thermal_count);

	smp_thermal_vector();

	irq_exit();

arch/x86/kernel/cpu/mcheck/threshold.c

+1 −1
Original line number Diff line number Diff line
@@ -19,8 +19,8 @@ void (*mce_threshold_vector)(void) = default_threshold_interrupt; 


asmlinkage void smp_threshold_interrupt(void)

{

	exit_idle();

	irq_enter();

	exit_idle();

	inc_irq_stat(irq_threshold_count);

	mce_threshold_vector();

	irq_exit();

arch/x86/kernel/irq.c

+3 −3
Original line number Diff line number Diff line
@@ -181,8 +181,8 @@ unsigned int __irq_entry do_IRQ(struct pt_regs *regs) 
	unsigned vector = ~regs->orig_ax;

	unsigned irq;



	exit_idle();

	irq_enter();

	exit_idle();



	irq = __this_cpu_read(vector_irq[vector]);
@@ -209,10 +209,10 @@ void smp_x86_platform_ipi(struct pt_regs *regs) 


	ack_APIC_irq();



	exit_idle();



	irq_enter();



	exit_idle();



	inc_irq_stat(x86_platform_ipis);



	if (x86_platform_ipi_callback)