3 files changed, 26 insertions, 33 deletions

diff --git a/arch/x86_64/kernel/smp.c b/arch/x86_64/kernel/smp.c
index 4f67697f503..9f74c883568 100644
--- a/arch/x86_64/kernel/smp.c
+++ b/arch/x86_64/kernel/smp.c
@@ -376,9 +376,8 @@ int smp_call_function_single (int cpu, void (*func) (void *info), void *info,
 	/* prevent preemption and reschedule on another processor */
 	int me = get_cpu();
 	if (cpu == me) {
-		WARN_ON(1);
 		put_cpu();
-		return -EBUSY;
+		return 0;
 	}
 	spin_lock_bh(&call_lock);
 	__smp_call_function_single(cpu, func, info, nonatomic, wait);
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index 88722f11ca1..e3ef544d2cf 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -876,15 +876,6 @@ static struct irqaction irq0 = {
 	timer_interrupt, IRQF_DISABLED, CPU_MASK_NONE, "timer", NULL, NULL
 };
 
-static int __cpuinit
-time_cpu_notifier(struct notifier_block *nb, unsigned long action, void *hcpu)
-{
-	unsigned cpu = (unsigned long) hcpu;
-	if (action == CPU_ONLINE)
-		vsyscall_set_cpu(cpu);
-	return NOTIFY_DONE;
-}
-
 void __init time_init(void)
 {
 	if (nohpet)
@@ -925,8 +916,6 @@ void __init time_init(void)
 	vxtime.last_tsc = get_cycles_sync();
 	set_cyc2ns_scale(cpu_khz);
 	setup_irq(0, &irq0);
-	hotcpu_notifier(time_cpu_notifier, 0);
-	time_cpu_notifier(NULL, CPU_ONLINE, (void *)(long)smp_processor_id());
 
 #ifndef CONFIG_SMP
 	time_init_gtod();
diff --git a/arch/x86_64/kernel/vsyscall.c b/arch/x86_64/kernel/vsyscall.c
index a98b460af6a..a730bacecb0 100644
--- a/arch/x86_64/kernel/vsyscall.c
+++ b/arch/x86_64/kernel/vsyscall.c
@@ -27,6 +27,9 @@
 #include <linux/jiffies.h>
 #include <linux/sysctl.h>
 #include <linux/getcpu.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <linux/notifier.h>
 
 #include <asm/vsyscall.h>
 #include <asm/pgtable.h>
@@ -243,32 +246,17 @@ static ctl_table kernel_root_table2[] = {
 
 #endif
 
-static void __cpuinit write_rdtscp_cb(void *info)
-{
-	write_rdtscp_aux((unsigned long)info);
-}
-
-void __cpuinit vsyscall_set_cpu(int cpu)
+/* Assume __initcall executes before all user space. Hopefully kmod
+   doesn't violate that. We'll find out if it does. */
+static void __cpuinit vsyscall_set_cpu(int cpu)
 {
 	unsigned long *d;
 	unsigned long node = 0;
 #ifdef CONFIG_NUMA
 	node = cpu_to_node[cpu];
 #endif
-	if (cpu_has(&cpu_data[cpu], X86_FEATURE_RDTSCP)) {
-		void *info = (void *)((node << 12) | cpu);
-		/* Can happen on preemptive kernel */
-		if (get_cpu() == cpu)
-			write_rdtscp_cb(info);
-#ifdef CONFIG_SMP
-		else {
-			/* the notifier is unfortunately not executed on the
-			   target CPU */
-			smp_call_function_single(cpu,write_rdtscp_cb,info,0,1);
-		}
-#endif
-		put_cpu();
-	}
+	if (cpu_has(&cpu_data[cpu], X86_FEATURE_RDTSCP))
+		write_rdtscp_aux((node << 12) | cpu);
 
 	/* Store cpu number in limit so that it can be loaded quickly
 	   in user space in vgetcpu.
@@ -280,6 +268,21 @@ void __cpuinit vsyscall_set_cpu(int cpu)
 	*d |= (node >> 4) << 48;
 }
 
+static void __cpuinit cpu_vsyscall_init(void *arg)
+{
+	/* preemption should be already off */
+	vsyscall_set_cpu(raw_smp_processor_id());
+}
+
+static int __cpuinit
+cpu_vsyscall_notifier(struct notifier_block *n, unsigned long action, void *arg)
+{
+	long cpu = (long)arg;
+	if (action == CPU_ONLINE)
+		smp_call_function_single(cpu, cpu_vsyscall_init, NULL, 0, 1);
+	return NOTIFY_DONE;
+}
+
 static void __init map_vsyscall(void)
 {
 	extern char __vsyscall_0;
@@ -299,6 +302,8 @@ static int __init vsyscall_init(void)
 #ifdef CONFIG_SYSCTL
 	register_sysctl_table(kernel_root_table2, 0);
 #endif
+	on_each_cpu(cpu_vsyscall_init, NULL, 0, 1);
+	hotcpu_notifier(cpu_vsyscall_notifier, 0);
 	return 0;
 }