Add the sysctls to control pbitmaps

- pbitmap_enabled: Master switch for pbitmap
- pbitmap_early_fault: Control whether pbitmap should do
early page faults or not. Default on.
- pbitmap_update_interval: How often the pbitmap should
be updated on disk.

Signed-off-by: Andi Kleen <andi@firstfloor.org>

---
 kernel/sysctl.c |   30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

Index: linux/kernel/sysctl.c
===================================================================
--- linux.orig/kernel/sysctl.c
+++ linux/kernel/sysctl.c
@@ -1044,6 +1044,36 @@ static struct ctl_table vm_table[] = {
 		.extra1		= &zero,
 	},
 	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "pbitmap_enabled",
+		.data		= &pbitmap_enabled,
+		.maxlen 	= sizeof(pbitmap_enabled),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+		.strategy	= &sysctl_intvec,
+		.extra1 	= &zero,
+	},
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "pbitmap_early_fault",
+		.data		= &pbitmap_early_fault,
+		.maxlen 	= sizeof(pbitmap_early_fault),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+		.strategy	= &sysctl_intvec,
+		.extra1 	= &zero,
+	},
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "pbitmap_update_interval",
+		.data		= &pbitmap_update_interval,
+		.maxlen 	= sizeof(pbitmap_update_interval),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+		.strategy	= &sysctl_intvec,
+		.extra1 	= &zero,
+	},
+	{
 		.ctl_name	= VM_VFS_CACHE_PRESSURE,
 		.procname	= "vfs_cache_pressure",
 		.data		= &sysctl_vfs_cache_pressure,