--- zzzz-none-000/linux-2.6.19.2/arch/x86_64/kernel/vsyscall.c	2007-01-10 19:10:37.000000000 +0000
+++ davinci-8020-5504/linux-2.6.19.2/arch/x86_64/kernel/vsyscall.c	2007-01-11 07:38:19.000000000 +0000
@@ -27,9 +27,6 @@
 #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>
@@ -246,17 +243,32 @@
 
 #endif
 
-/* 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)
+static void __cpuinit write_rdtscp_cb(void *info)
+{
+	write_rdtscp_aux((unsigned long)info);
+}
+
+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))
-		write_rdtscp_aux((node << 12) | cpu);
+	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();
+	}
 
 	/* Store cpu number in limit so that it can be loaded quickly
 	   in user space in vgetcpu.
@@ -268,23 +280,6 @@
 	*d |= (node >> 4) << 48;
 }
 
-static void __cpuinit cpu_vsyscall_init(void *arg)
-{
-	/* preemption should be already off */
-	vsyscall_set_cpu(raw_smp_processor_id());
-}
-
-#ifdef CONFIG_HOTPLUG_CPU
-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;
-}
-#endif
-
 static void __init map_vsyscall(void)
 {
 	extern char __vsyscall_0;
@@ -304,8 +299,6 @@
 #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;
 }