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+ analogdevicesinc#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: Frederic Weisbecker <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Andy Henroid <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> Reviewed-by: Josh Triplett <[email protected]>
mrcsosa · Dec 11, 2011 · 98ad1cc · 98ad1cc
1 parent e37e112
commit 98ad1cc
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Showing 5 changed files with 9 additions and 9 deletions.
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
@@ -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);

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
@@ -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++) {

diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c
@@ -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();

diff --git a/arch/x86/kernel/cpu/mcheck/threshold.c b/arch/x86/kernel/cpu/mcheck/threshold.c
@@ -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();

diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
@@ -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)