Merge branch 'xen-tmem-selfballoon-v8' of...

Merge branch 'xen-tmem-selfballoon-v8' of git://git.kernel.org/pub/scm/linux/kernel/git/djm/tmem into stable/drivers

* 'xen-tmem-selfballoon-v8' of git://git.kernel.org/pub/scm/linux/kernel/git/djm/tmem:
  xen: tmem: self-ballooning and frontswap-selfshrinking

drivers/xen/Kconfig

@@ -9,6 +9,23 @@ config XEN_BALLOON
 	  the system to expand the domain's memory allocation, or alternatively
 	  return unneeded memory to the system.
 
+config XEN_SELFBALLOONING
+	bool "Dynamically self-balloon kernel memory to target"
+	depends on XEN && XEN_BALLOON && CLEANCACHE && SWAP
+	default n
+	help
+	  Self-ballooning dynamically balloons available kernel memory driven
+	  by the current usage of anonymous memory ("committed AS") and
+	  controlled by various sysfs-settable parameters.  Configuring
+	  FRONTSWAP is highly recommended; if it is not configured, self-
+	  ballooning is disabled by default but can be enabled with the
+	  'selfballooning' kernel boot parameter.  If FRONTSWAP is configured,
+	  frontswap-selfshrinking is enabled by default but can be disabled
+	  with the 'noselfshrink' kernel boot parameter; and self-ballooning
+	  is enabled by default but can be disabled with the 'noselfballooning'
+	  kernel boot parameter.  Note that systems without a sufficiently
+	  large swap device should not enable self-ballooning.
+
 config XEN_SCRUB_PAGES
 	bool "Scrub pages before returning them to system"
 	depends on XEN_BALLOON

drivers/xen/Makefile

@@ -8,6 +8,7 @@ obj-$(CONFIG_BLOCK)			+= biomerge.o
 obj-$(CONFIG_HOTPLUG_CPU)		+= cpu_hotplug.o
 obj-$(CONFIG_XEN_XENCOMM)		+= xencomm.o
 obj-$(CONFIG_XEN_BALLOON)		+= xen-balloon.o
+obj-$(CONFIG_XEN_SELFBALLOONING)	+= xen-selfballoon.o
 obj-$(CONFIG_XEN_DEV_EVTCHN)		+= xen-evtchn.o
 obj-$(CONFIG_XEN_GNTDEV)		+= xen-gntdev.o
 obj-$(CONFIG_XEN_GRANT_DEV_ALLOC)	+= xen-gntalloc.o

drivers/xen/xen-balloon.c

@@ -98,6 +98,8 @@ static int __init balloon_init(void)
 
 	register_balloon(&balloon_sysdev);
 
+	register_xen_selfballooning(&balloon_sysdev);
+
 	target_watch.callback = watch_target;
 	xenstore_notifier.notifier_call = balloon_init_watcher;
 

include/xen/balloon.h

@@ -23,3 +23,13 @@ void balloon_set_new_target(unsigned long target);
 
 int alloc_xenballooned_pages(int nr_pages, struct page** pages);
 void free_xenballooned_pages(int nr_pages, struct page** pages);
+
+struct sys_device;
+#ifdef CONFIG_XEN_SELFBALLOONING
+extern int register_xen_selfballooning(struct sys_device *sysdev);
+#else
+static inline int register_xen_selfballooning(struct sys_device *sysdev)
+{
+	return -ENOSYS;
+}
+#endif

include/xen/tmem.h

+#ifndef _XEN_TMEM_H
+#define _XEN_TMEM_H
+/* defined in drivers/xen/tmem.c */
+extern int tmem_enabled;
+#endif /* _XEN_TMEM_H */